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fs/dcache.c
93.5 KB
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/* * fs/dcache.c * * Complete reimplementation * (C) 1997 Thomas Schoebel-Theuer, * with heavy changes by Linus Torvalds */ /* * Notes on the allocation strategy: * * The dcache is a master of the icache - whenever a dcache entry * exists, the inode will always exist. "iput()" is done either when * the dcache entry is deleted or garbage collected. */ |
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#include <linux/syscalls.h> #include <linux/string.h> #include <linux/mm.h> #include <linux/fs.h> |
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#include <linux/fsnotify.h> |
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#include <linux/slab.h> #include <linux/init.h> |
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#include <linux/hash.h> #include <linux/cache.h> |
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#include <linux/export.h> |
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#include <linux/mount.h> #include <linux/file.h> #include <asm/uaccess.h> #include <linux/security.h> #include <linux/seqlock.h> #include <linux/swap.h> #include <linux/bootmem.h> |
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#include <linux/fs_struct.h> |
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#include <linux/hardirq.h> |
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#include <linux/bit_spinlock.h> #include <linux/rculist_bl.h> |
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#include <linux/prefetch.h> |
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#include <linux/ratelimit.h> |
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#include <linux/list_lru.h> |
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#include <linux/kasan.h> |
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#include "internal.h" |
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#include "mount.h" |
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/* * Usage: |
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* dcache->d_inode->i_lock protects: |
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* - i_dentry, d_u.d_alias, d_inode of aliases |
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* dcache_hash_bucket lock protects: * - the dcache hash table * s_anon bl list spinlock protects: * - the s_anon list (see __d_drop) |
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* dentry->d_sb->s_dentry_lru_lock protects: |
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* - the dcache lru lists and counters * d_lock protects: * - d_flags * - d_name * - d_lru |
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* - d_count |
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* - d_unhashed() |
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* - d_parent and d_subdirs * - childrens' d_child and d_parent |
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* - d_u.d_alias, d_inode |
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* * Ordering: |
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* dentry->d_inode->i_lock |
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* dentry->d_lock |
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* dentry->d_sb->s_dentry_lru_lock |
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* dcache_hash_bucket lock * s_anon lock |
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* |
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* If there is an ancestor relationship: * dentry->d_parent->...->d_parent->d_lock * ... * dentry->d_parent->d_lock * dentry->d_lock * * If no ancestor relationship: |
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* if (dentry1 < dentry2) * dentry1->d_lock * dentry2->d_lock */ |
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int sysctl_vfs_cache_pressure __read_mostly = 100; |
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EXPORT_SYMBOL_GPL(sysctl_vfs_cache_pressure); |
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__cacheline_aligned_in_smp DEFINE_SEQLOCK(rename_lock); |
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EXPORT_SYMBOL(rename_lock); |
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static struct kmem_cache *dentry_cache __read_mostly; |
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/* * This is the single most critical data structure when it comes * to the dcache: the hashtable for lookups. Somebody should try * to make this good - I've just made it work. * * This hash-function tries to avoid losing too many bits of hash * information, yet avoid using a prime hash-size or similar. */ |
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static unsigned int d_hash_mask __read_mostly; static unsigned int d_hash_shift __read_mostly; |
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static struct hlist_bl_head *dentry_hashtable __read_mostly; |
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static inline struct hlist_bl_head *d_hash(unsigned int hash) |
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{ |
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return dentry_hashtable + (hash >> (32 - d_hash_shift)); |
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} |
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#define IN_LOOKUP_SHIFT 10 static struct hlist_bl_head in_lookup_hashtable[1 << IN_LOOKUP_SHIFT]; static inline struct hlist_bl_head *in_lookup_hash(const struct dentry *parent, unsigned int hash) { hash += (unsigned long) parent / L1_CACHE_BYTES; return in_lookup_hashtable + hash_32(hash, IN_LOOKUP_SHIFT); } |
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/* Statistics gathering. */ struct dentry_stat_t dentry_stat = { .age_limit = 45, }; |
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static DEFINE_PER_CPU(long, nr_dentry); |
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static DEFINE_PER_CPU(long, nr_dentry_unused); |
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#if defined(CONFIG_SYSCTL) && defined(CONFIG_PROC_FS) |
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/* * Here we resort to our own counters instead of using generic per-cpu counters * for consistency with what the vfs inode code does. We are expected to harvest * better code and performance by having our own specialized counters. * * Please note that the loop is done over all possible CPUs, not over all online * CPUs. The reason for this is that we don't want to play games with CPUs going * on and off. If one of them goes off, we will just keep their counters. * * glommer: See cffbc8a for details, and if you ever intend to change this, * please update all vfs counters to match. */ |
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static long get_nr_dentry(void) |
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{ int i; |
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long sum = 0; |
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for_each_possible_cpu(i) sum += per_cpu(nr_dentry, i); return sum < 0 ? 0 : sum; } |
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static long get_nr_dentry_unused(void) { int i; long sum = 0; for_each_possible_cpu(i) sum += per_cpu(nr_dentry_unused, i); return sum < 0 ? 0 : sum; } |
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int proc_nr_dentry(struct ctl_table *table, int write, void __user *buffer, |
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size_t *lenp, loff_t *ppos) { |
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dentry_stat.nr_dentry = get_nr_dentry(); |
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dentry_stat.nr_unused = get_nr_dentry_unused(); |
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return proc_doulongvec_minmax(table, write, buffer, lenp, ppos); |
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} #endif |
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/* * Compare 2 name strings, return 0 if they match, otherwise non-zero. * The strings are both count bytes long, and count is non-zero. */ |
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#ifdef CONFIG_DCACHE_WORD_ACCESS #include <asm/word-at-a-time.h> /* * NOTE! 'cs' and 'scount' come from a dentry, so it has a * aligned allocation for this particular component. We don't * strictly need the load_unaligned_zeropad() safety, but it * doesn't hurt either. * * In contrast, 'ct' and 'tcount' can be from a pathname, and do * need the careful unaligned handling. */ |
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static inline int dentry_string_cmp(const unsigned char *cs, const unsigned char *ct, unsigned tcount) |
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{ |
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unsigned long a,b,mask; |
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for (;;) { |
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a = *(unsigned long *)cs; |
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b = load_unaligned_zeropad(ct); |
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if (tcount < sizeof(unsigned long)) break; if (unlikely(a != b)) return 1; cs += sizeof(unsigned long); ct += sizeof(unsigned long); tcount -= sizeof(unsigned long); if (!tcount) return 0; } |
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mask = bytemask_from_count(tcount); |
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return unlikely(!!((a ^ b) & mask)); |
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} |
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#else |
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static inline int dentry_string_cmp(const unsigned char *cs, const unsigned char *ct, unsigned tcount) |
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{ |
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do { if (*cs != *ct) return 1; cs++; ct++; tcount--; } while (tcount); return 0; } |
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#endif |
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static inline int dentry_cmp(const struct dentry *dentry, const unsigned char *ct, unsigned tcount) { |
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/* * Be careful about RCU walk racing with rename: |
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* use 'lockless_dereference' to fetch the name pointer. |
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* * NOTE! Even if a rename will mean that the length * was not loaded atomically, we don't care. The * RCU walk will check the sequence count eventually, * and catch it. And we won't overrun the buffer, * because we're reading the name pointer atomically, * and a dentry name is guaranteed to be properly * terminated with a NUL byte. * * End result: even if 'len' is wrong, we'll exit * early because the data cannot match (there can * be no NUL in the ct/tcount data) */ |
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const unsigned char *cs = lockless_dereference(dentry->d_name.name); |
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return dentry_string_cmp(cs, ct, tcount); |
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} |
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struct external_name { union { atomic_t count; struct rcu_head head; } u; unsigned char name[]; }; static inline struct external_name *external_name(struct dentry *dentry) { return container_of(dentry->d_name.name, struct external_name, name[0]); } |
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static void __d_free(struct rcu_head *head) |
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{ |
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struct dentry *dentry = container_of(head, struct dentry, d_u.d_rcu); |
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kmem_cache_free(dentry_cache, dentry); } static void __d_free_external(struct rcu_head *head) { struct dentry *dentry = container_of(head, struct dentry, d_u.d_rcu); |
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kfree(external_name(dentry)); |
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kmem_cache_free(dentry_cache, dentry); } |
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static inline int dname_external(const struct dentry *dentry) { return dentry->d_name.name != dentry->d_iname; } |
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static inline void __d_set_inode_and_type(struct dentry *dentry, struct inode *inode, unsigned type_flags) { unsigned flags; dentry->d_inode = inode; |
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flags = READ_ONCE(dentry->d_flags); flags &= ~(DCACHE_ENTRY_TYPE | DCACHE_FALLTHRU); flags |= type_flags; WRITE_ONCE(dentry->d_flags, flags); } |
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static inline void __d_clear_type_and_inode(struct dentry *dentry) { unsigned flags = READ_ONCE(dentry->d_flags); flags &= ~(DCACHE_ENTRY_TYPE | DCACHE_FALLTHRU); WRITE_ONCE(dentry->d_flags, flags); |
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dentry->d_inode = NULL; } |
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static void dentry_free(struct dentry *dentry) { |
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WARN_ON(!hlist_unhashed(&dentry->d_u.d_alias)); |
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if (unlikely(dname_external(dentry))) { struct external_name *p = external_name(dentry); if (likely(atomic_dec_and_test(&p->u.count))) { call_rcu(&dentry->d_u.d_rcu, __d_free_external); return; } } |
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/* if dentry was never visible to RCU, immediate free is OK */ if (!(dentry->d_flags & DCACHE_RCUACCESS)) __d_free(&dentry->d_u.d_rcu); else call_rcu(&dentry->d_u.d_rcu, __d_free); } |
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/* * Release the dentry's inode, using the filesystem |
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* d_iput() operation if defined. |
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*/ static void dentry_unlink_inode(struct dentry * dentry) __releases(dentry->d_lock) |
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__releases(dentry->d_inode->i_lock) |
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{ struct inode *inode = dentry->d_inode; |
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bool hashed = !d_unhashed(dentry); |
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if (hashed) raw_write_seqcount_begin(&dentry->d_seq); |
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__d_clear_type_and_inode(dentry); |
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hlist_del_init(&dentry->d_u.d_alias); |
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if (hashed) raw_write_seqcount_end(&dentry->d_seq); |
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spin_unlock(&dentry->d_lock); |
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spin_unlock(&inode->i_lock); |
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if (!inode->i_nlink) fsnotify_inoderemove(inode); if (dentry->d_op && dentry->d_op->d_iput) dentry->d_op->d_iput(dentry, inode); else iput(inode); } /* |
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* The DCACHE_LRU_LIST bit is set whenever the 'd_lru' entry * is in use - which includes both the "real" per-superblock * LRU list _and_ the DCACHE_SHRINK_LIST use. * * The DCACHE_SHRINK_LIST bit is set whenever the dentry is * on the shrink list (ie not on the superblock LRU list). * * The per-cpu "nr_dentry_unused" counters are updated with * the DCACHE_LRU_LIST bit. * * These helper functions make sure we always follow the * rules. d_lock must be held by the caller. */ #define D_FLAG_VERIFY(dentry,x) WARN_ON_ONCE(((dentry)->d_flags & (DCACHE_LRU_LIST | DCACHE_SHRINK_LIST)) != (x)) static void d_lru_add(struct dentry *dentry) { D_FLAG_VERIFY(dentry, 0); dentry->d_flags |= DCACHE_LRU_LIST; this_cpu_inc(nr_dentry_unused); WARN_ON_ONCE(!list_lru_add(&dentry->d_sb->s_dentry_lru, &dentry->d_lru)); } static void d_lru_del(struct dentry *dentry) { D_FLAG_VERIFY(dentry, DCACHE_LRU_LIST); dentry->d_flags &= ~DCACHE_LRU_LIST; this_cpu_dec(nr_dentry_unused); WARN_ON_ONCE(!list_lru_del(&dentry->d_sb->s_dentry_lru, &dentry->d_lru)); } static void d_shrink_del(struct dentry *dentry) { D_FLAG_VERIFY(dentry, DCACHE_SHRINK_LIST | DCACHE_LRU_LIST); list_del_init(&dentry->d_lru); dentry->d_flags &= ~(DCACHE_SHRINK_LIST | DCACHE_LRU_LIST); this_cpu_dec(nr_dentry_unused); } static void d_shrink_add(struct dentry *dentry, struct list_head *list) { D_FLAG_VERIFY(dentry, 0); list_add(&dentry->d_lru, list); dentry->d_flags |= DCACHE_SHRINK_LIST | DCACHE_LRU_LIST; this_cpu_inc(nr_dentry_unused); } /* * These can only be called under the global LRU lock, ie during the * callback for freeing the LRU list. "isolate" removes it from the * LRU lists entirely, while shrink_move moves it to the indicated * private list. */ |
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static void d_lru_isolate(struct list_lru_one *lru, struct dentry *dentry) |
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{ D_FLAG_VERIFY(dentry, DCACHE_LRU_LIST); dentry->d_flags &= ~DCACHE_LRU_LIST; this_cpu_dec(nr_dentry_unused); |
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list_lru_isolate(lru, &dentry->d_lru); |
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} |
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static void d_lru_shrink_move(struct list_lru_one *lru, struct dentry *dentry, struct list_head *list) |
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{ D_FLAG_VERIFY(dentry, DCACHE_LRU_LIST); dentry->d_flags |= DCACHE_SHRINK_LIST; |
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list_lru_isolate_move(lru, &dentry->d_lru, list); |
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} /* |
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* dentry_lru_(add|del)_list) must be called with d_lock held. |
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*/ static void dentry_lru_add(struct dentry *dentry) { |
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if (unlikely(!(dentry->d_flags & DCACHE_LRU_LIST))) d_lru_add(dentry); |
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} |
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/** |
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* d_drop - drop a dentry * @dentry: dentry to drop * * d_drop() unhashes the entry from the parent dentry hashes, so that it won't * be found through a VFS lookup any more. Note that this is different from * deleting the dentry - d_delete will try to mark the dentry negative if * possible, giving a successful _negative_ lookup, while d_drop will * just make the cache lookup fail. * * d_drop() is used mainly for stuff that wants to invalidate a dentry for some * reason (NFS timeouts or autofs deletes). * * __d_drop requires dentry->d_lock. */ void __d_drop(struct dentry *dentry) { |
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if (!d_unhashed(dentry)) { |
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struct hlist_bl_head *b; |
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/* * Hashed dentries are normally on the dentry hashtable, * with the exception of those newly allocated by * d_obtain_alias, which are always IS_ROOT: */ if (unlikely(IS_ROOT(dentry))) |
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b = &dentry->d_sb->s_anon; else |
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b = d_hash(dentry->d_name.hash); |
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hlist_bl_lock(b); __hlist_bl_del(&dentry->d_hash); dentry->d_hash.pprev = NULL; hlist_bl_unlock(b); |
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/* After this call, in-progress rcu-walk path lookup will fail. */ write_seqcount_invalidate(&dentry->d_seq); |
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} } EXPORT_SYMBOL(__d_drop); void d_drop(struct dentry *dentry) { |
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spin_lock(&dentry->d_lock); __d_drop(dentry); spin_unlock(&dentry->d_lock); |
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} EXPORT_SYMBOL(d_drop); |
ba65dc5ef much milder d_wal... |
446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 |
static inline void dentry_unlist(struct dentry *dentry, struct dentry *parent) { struct dentry *next; /* * Inform d_walk() and shrink_dentry_list() that we are no longer * attached to the dentry tree */ dentry->d_flags |= DCACHE_DENTRY_KILLED; if (unlikely(list_empty(&dentry->d_child))) return; __list_del_entry(&dentry->d_child); /* * Cursors can move around the list of children. While we'd been * a normal list member, it didn't matter - ->d_child.next would've * been updated. However, from now on it won't be and for the * things like d_walk() it might end up with a nasty surprise. * Normally d_walk() doesn't care about cursors moving around - * ->d_lock on parent prevents that and since a cursor has no children * of its own, we get through it without ever unlocking the parent. * There is one exception, though - if we ascend from a child that * gets killed as soon as we unlock it, the next sibling is found * using the value left in its ->d_child.next. And if _that_ * pointed to a cursor, and cursor got moved (e.g. by lseek()) * before d_walk() regains parent->d_lock, we'll end up skipping * everything the cursor had been moved past. * * Solution: make sure that the pointer left behind in ->d_child.next * points to something that won't be moving around. I.e. skip the * cursors. */ while (dentry->d_child.next != &parent->d_subdirs) { next = list_entry(dentry->d_child.next, struct dentry, d_child); if (likely(!(next->d_flags & DCACHE_DENTRY_CURSOR))) break; dentry->d_child.next = next->d_child.next; } } |
e55fd0115 split dentry_kill() |
483 |
static void __dentry_kill(struct dentry *dentry) |
77812a1ef fs: consolidate d... |
484 |
{ |
41edf278f dentry_kill(): do... |
485 486 |
struct dentry *parent = NULL; bool can_free = true; |
41edf278f dentry_kill(): do... |
487 |
if (!IS_ROOT(dentry)) |
77812a1ef fs: consolidate d... |
488 |
parent = dentry->d_parent; |
31e6b01f4 fs: rcu-walk for ... |
489 |
|
0d98439ea vfs: use lockred ... |
490 491 492 493 |
/* * The dentry is now unrecoverably dead to the world. */ lockref_mark_dead(&dentry->d_lockref); |
f0023bc61 vfs: add d_prune ... |
494 |
/* |
f0023bc61 vfs: add d_prune ... |
495 496 497 |
* inform the fs via d_prune that this dentry is about to be * unhashed and destroyed. */ |
292662014 dcache.c: call ->... |
498 |
if (dentry->d_flags & DCACHE_OP_PRUNE) |
61572bb1f fs: remove dentry... |
499 |
dentry->d_op->d_prune(dentry); |
01b603519 expand the call o... |
500 501 502 |
if (dentry->d_flags & DCACHE_LRU_LIST) { if (!(dentry->d_flags & DCACHE_SHRINK_LIST)) d_lru_del(dentry); |
01b603519 expand the call o... |
503 |
} |
77812a1ef fs: consolidate d... |
504 505 |
/* if it was on the hash then remove it */ __d_drop(dentry); |
ba65dc5ef much milder d_wal... |
506 |
dentry_unlist(dentry, parent); |
03b3b889e fold d_kill() and... |
507 508 |
if (parent) spin_unlock(&parent->d_lock); |
550dce01d unify dentry_iput... |
509 510 511 512 |
if (dentry->d_inode) dentry_unlink_inode(dentry); else spin_unlock(&dentry->d_lock); |
03b3b889e fold d_kill() and... |
513 514 515 |
this_cpu_dec(nr_dentry); if (dentry->d_op && dentry->d_op->d_release) dentry->d_op->d_release(dentry); |
41edf278f dentry_kill(): do... |
516 517 518 519 520 521 |
spin_lock(&dentry->d_lock); if (dentry->d_flags & DCACHE_SHRINK_LIST) { dentry->d_flags |= DCACHE_MAY_FREE; can_free = false; } spin_unlock(&dentry->d_lock); |
41edf278f dentry_kill(): do... |
522 523 |
if (likely(can_free)) dentry_free(dentry); |
e55fd0115 split dentry_kill() |
524 525 526 527 528 529 530 531 |
} /* * Finish off a dentry we've decided to kill. * dentry->d_lock must be held, returns with it unlocked. * If ref is non-zero, then decrement the refcount too. * Returns dentry requiring refcount drop, or NULL if we're done. */ |
8cbf74da4 dentry_kill() doe... |
532 |
static struct dentry *dentry_kill(struct dentry *dentry) |
e55fd0115 split dentry_kill() |
533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 |
__releases(dentry->d_lock) { struct inode *inode = dentry->d_inode; struct dentry *parent = NULL; if (inode && unlikely(!spin_trylock(&inode->i_lock))) goto failed; if (!IS_ROOT(dentry)) { parent = dentry->d_parent; if (unlikely(!spin_trylock(&parent->d_lock))) { if (inode) spin_unlock(&inode->i_lock); goto failed; } } __dentry_kill(dentry); |
03b3b889e fold d_kill() and... |
551 |
return parent; |
e55fd0115 split dentry_kill() |
552 553 |
failed: |
8cbf74da4 dentry_kill() doe... |
554 |
spin_unlock(&dentry->d_lock); |
e55fd0115 split dentry_kill() |
555 |
return dentry; /* try again with same dentry */ |
77812a1ef fs: consolidate d... |
556 |
} |
046b961b4 shrink_dentry_lis... |
557 558 559 560 561 |
static inline struct dentry *lock_parent(struct dentry *dentry) { struct dentry *parent = dentry->d_parent; if (IS_ROOT(dentry)) return NULL; |
360f54796 dcache: let the d... |
562 |
if (unlikely(dentry->d_lockref.count < 0)) |
c2338f2dc lock_parent: don'... |
563 |
return NULL; |
046b961b4 shrink_dentry_lis... |
564 565 |
if (likely(spin_trylock(&parent->d_lock))) return parent; |
046b961b4 shrink_dentry_lis... |
566 |
rcu_read_lock(); |
c2338f2dc lock_parent: don'... |
567 |
spin_unlock(&dentry->d_lock); |
046b961b4 shrink_dentry_lis... |
568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 |
again: parent = ACCESS_ONCE(dentry->d_parent); spin_lock(&parent->d_lock); /* * We can't blindly lock dentry until we are sure * that we won't violate the locking order. * Any changes of dentry->d_parent must have * been done with parent->d_lock held, so * spin_lock() above is enough of a barrier * for checking if it's still our child. */ if (unlikely(parent != dentry->d_parent)) { spin_unlock(&parent->d_lock); goto again; } rcu_read_unlock(); if (parent != dentry) |
9f12600fe dcache: add missi... |
585 |
spin_lock_nested(&dentry->d_lock, DENTRY_D_LOCK_NESTED); |
046b961b4 shrink_dentry_lis... |
586 587 588 589 |
else parent = NULL; return parent; } |
360f54796 dcache: let the d... |
590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 |
/* * Try to do a lockless dput(), and return whether that was successful. * * If unsuccessful, we return false, having already taken the dentry lock. * * The caller needs to hold the RCU read lock, so that the dentry is * guaranteed to stay around even if the refcount goes down to zero! */ static inline bool fast_dput(struct dentry *dentry) { int ret; unsigned int d_flags; /* * If we have a d_op->d_delete() operation, we sould not |
75a6f82a0 freeing unlinked ... |
605 |
* let the dentry count go to zero, so use "put_or_lock". |
360f54796 dcache: let the d... |
606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 |
*/ if (unlikely(dentry->d_flags & DCACHE_OP_DELETE)) return lockref_put_or_lock(&dentry->d_lockref); /* * .. otherwise, we can try to just decrement the * lockref optimistically. */ ret = lockref_put_return(&dentry->d_lockref); /* * If the lockref_put_return() failed due to the lock being held * by somebody else, the fast path has failed. We will need to * get the lock, and then check the count again. */ if (unlikely(ret < 0)) { spin_lock(&dentry->d_lock); if (dentry->d_lockref.count > 1) { dentry->d_lockref.count--; spin_unlock(&dentry->d_lock); return 1; } return 0; } /* * If we weren't the last ref, we're done. */ if (ret) return 1; /* * Careful, careful. The reference count went down * to zero, but we don't hold the dentry lock, so * somebody else could get it again, and do another * dput(), and we need to not race with that. * * However, there is a very special and common case * where we don't care, because there is nothing to * do: the dentry is still hashed, it does not have * a 'delete' op, and it's referenced and already on * the LRU list. * * NOTE! Since we aren't locked, these values are * not "stable". However, it is sufficient that at * some point after we dropped the reference the * dentry was hashed and the flags had the proper * value. Other dentry users may have re-gotten * a reference to the dentry and change that, but * our work is done - we can leave the dentry * around with a zero refcount. */ smp_rmb(); d_flags = ACCESS_ONCE(dentry->d_flags); |
75a6f82a0 freeing unlinked ... |
660 |
d_flags &= DCACHE_REFERENCED | DCACHE_LRU_LIST | DCACHE_DISCONNECTED; |
360f54796 dcache: let the d... |
661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 |
/* Nothing to do? Dropping the reference was all we needed? */ if (d_flags == (DCACHE_REFERENCED | DCACHE_LRU_LIST) && !d_unhashed(dentry)) return 1; /* * Not the fast normal case? Get the lock. We've already decremented * the refcount, but we'll need to re-check the situation after * getting the lock. */ spin_lock(&dentry->d_lock); /* * Did somebody else grab a reference to it in the meantime, and * we're no longer the last user after all? Alternatively, somebody * else could have killed it and marked it dead. Either way, we * don't need to do anything else. */ if (dentry->d_lockref.count) { spin_unlock(&dentry->d_lock); return 1; } /* * Re-get the reference we optimistically dropped. We hold the * lock, and we just tested that it was zero, so we can just * set it to 1. */ dentry->d_lockref.count = 1; return 0; } |
1da177e4c Linux-2.6.12-rc2 |
692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 |
/* * This is dput * * This is complicated by the fact that we do not want to put * dentries that are no longer on any hash chain on the unused * list: we'd much rather just get rid of them immediately. * * However, that implies that we have to traverse the dentry * tree upwards to the parents which might _also_ now be * scheduled for deletion (it may have been only waiting for * its last child to go away). * * This tail recursion is done by hand as we don't want to depend * on the compiler to always get this right (gcc generally doesn't). * Real recursion would eat up our stack space. */ /* * dput - release a dentry * @dentry: dentry to release * * Release a dentry. This will drop the usage count and if appropriate * call the dentry unlink method as well as removing it from the queues and * releasing its resources. If the parent dentries were scheduled for release * they too may now get deleted. |
1da177e4c Linux-2.6.12-rc2 |
717 |
*/ |
1da177e4c Linux-2.6.12-rc2 |
718 719 |
void dput(struct dentry *dentry) { |
8aab6a273 vfs: reorganize d... |
720 |
if (unlikely(!dentry)) |
1da177e4c Linux-2.6.12-rc2 |
721 722 723 |
return; repeat: |
47be61845 fs/dcache.c: avoi... |
724 |
might_sleep(); |
360f54796 dcache: let the d... |
725 726 727 |
rcu_read_lock(); if (likely(fast_dput(dentry))) { rcu_read_unlock(); |
1da177e4c Linux-2.6.12-rc2 |
728 |
return; |
360f54796 dcache: let the d... |
729 730 731 732 |
} /* Slow case: now with the dentry lock held */ rcu_read_unlock(); |
1da177e4c Linux-2.6.12-rc2 |
733 |
|
85c7f8104 beginning of tran... |
734 |
WARN_ON(d_in_lookup(dentry)); |
8aab6a273 vfs: reorganize d... |
735 736 737 |
/* Unreachable? Get rid of it */ if (unlikely(d_unhashed(dentry))) goto kill_it; |
75a6f82a0 freeing unlinked ... |
738 739 |
if (unlikely(dentry->d_flags & DCACHE_DISCONNECTED)) goto kill_it; |
8aab6a273 vfs: reorganize d... |
740 |
if (unlikely(dentry->d_flags & DCACHE_OP_DELETE)) { |
1da177e4c Linux-2.6.12-rc2 |
741 |
if (dentry->d_op->d_delete(dentry)) |
61f3dee4a fs: dcache reduce... |
742 |
goto kill_it; |
1da177e4c Linux-2.6.12-rc2 |
743 |
} |
265ac9023 fs: improve DCACH... |
744 |
|
358eec182 vfs: decrapify dp... |
745 746 |
if (!(dentry->d_flags & DCACHE_REFERENCED)) dentry->d_flags |= DCACHE_REFERENCED; |
a4633357a fs: clean up dent... |
747 |
dentry_lru_add(dentry); |
265ac9023 fs: improve DCACH... |
748 |
|
98474236f vfs: make the den... |
749 |
dentry->d_lockref.count--; |
61f3dee4a fs: dcache reduce... |
750 |
spin_unlock(&dentry->d_lock); |
1da177e4c Linux-2.6.12-rc2 |
751 |
return; |
d52b90864 fix quadratic beh... |
752 |
kill_it: |
8cbf74da4 dentry_kill() doe... |
753 |
dentry = dentry_kill(dentry); |
47be61845 fs/dcache.c: avoi... |
754 755 |
if (dentry) { cond_resched(); |
d52b90864 fix quadratic beh... |
756 |
goto repeat; |
47be61845 fs/dcache.c: avoi... |
757 |
} |
1da177e4c Linux-2.6.12-rc2 |
758 |
} |
ec4f86059 fs/dcache.c: Codi... |
759 |
EXPORT_SYMBOL(dput); |
1da177e4c Linux-2.6.12-rc2 |
760 |
|
1da177e4c Linux-2.6.12-rc2 |
761 |
|
b5c84bf6f fs: dcache remove... |
762 |
/* This must be called with d_lock held */ |
dc0474be3 fs: dcache ration... |
763 |
static inline void __dget_dlock(struct dentry *dentry) |
230445078 fs: dcache scale lru |
764 |
{ |
98474236f vfs: make the den... |
765 |
dentry->d_lockref.count++; |
230445078 fs: dcache scale lru |
766 |
} |
dc0474be3 fs: dcache ration... |
767 |
static inline void __dget(struct dentry *dentry) |
1da177e4c Linux-2.6.12-rc2 |
768 |
{ |
98474236f vfs: make the den... |
769 |
lockref_get(&dentry->d_lockref); |
1da177e4c Linux-2.6.12-rc2 |
770 |
} |
b7ab39f63 fs: dcache scale ... |
771 772 |
struct dentry *dget_parent(struct dentry *dentry) { |
df3d0bbcd vfs: use lockref_... |
773 |
int gotref; |
b7ab39f63 fs: dcache scale ... |
774 |
struct dentry *ret; |
df3d0bbcd vfs: use lockref_... |
775 776 777 778 779 780 781 782 783 784 785 786 787 |
/* * Do optimistic parent lookup without any * locking. */ rcu_read_lock(); ret = ACCESS_ONCE(dentry->d_parent); gotref = lockref_get_not_zero(&ret->d_lockref); rcu_read_unlock(); if (likely(gotref)) { if (likely(ret == ACCESS_ONCE(dentry->d_parent))) return ret; dput(ret); } |
b7ab39f63 fs: dcache scale ... |
788 |
repeat: |
a734eb458 fs: dcache reduce... |
789 790 791 792 793 |
/* * Don't need rcu_dereference because we re-check it was correct under * the lock. */ rcu_read_lock(); |
b7ab39f63 fs: dcache scale ... |
794 |
ret = dentry->d_parent; |
a734eb458 fs: dcache reduce... |
795 796 797 798 |
spin_lock(&ret->d_lock); if (unlikely(ret != dentry->d_parent)) { spin_unlock(&ret->d_lock); rcu_read_unlock(); |
b7ab39f63 fs: dcache scale ... |
799 800 |
goto repeat; } |
a734eb458 fs: dcache reduce... |
801 |
rcu_read_unlock(); |
98474236f vfs: make the den... |
802 803 |
BUG_ON(!ret->d_lockref.count); ret->d_lockref.count++; |
b7ab39f63 fs: dcache scale ... |
804 |
spin_unlock(&ret->d_lock); |
b7ab39f63 fs: dcache scale ... |
805 806 807 |
return ret; } EXPORT_SYMBOL(dget_parent); |
1da177e4c Linux-2.6.12-rc2 |
808 809 810 |
/** * d_find_alias - grab a hashed alias of inode * @inode: inode in question |
1da177e4c Linux-2.6.12-rc2 |
811 812 813 814 815 |
* * If inode has a hashed alias, or is a directory and has any alias, * acquire the reference to alias and return it. Otherwise return NULL. * Notice that if inode is a directory there can be only one alias and * it can be unhashed only if it has no children, or if it is the root |
3ccb354d6 vfs: Document the... |
816 817 |
* of a filesystem, or if the directory was renamed and d_revalidate * was the first vfs operation to notice. |
1da177e4c Linux-2.6.12-rc2 |
818 |
* |
21c0d8fdd [PATCH] knfsd: cl... |
819 |
* If the inode has an IS_ROOT, DCACHE_DISCONNECTED alias, then prefer |
52ed46f0f dcache: remove un... |
820 |
* any other hashed alias over that one. |
1da177e4c Linux-2.6.12-rc2 |
821 |
*/ |
52ed46f0f dcache: remove un... |
822 |
static struct dentry *__d_find_alias(struct inode *inode) |
1da177e4c Linux-2.6.12-rc2 |
823 |
{ |
da5029563 fs: dcache scale ... |
824 |
struct dentry *alias, *discon_alias; |
1da177e4c Linux-2.6.12-rc2 |
825 |
|
da5029563 fs: dcache scale ... |
826 827 |
again: discon_alias = NULL; |
946e51f2b move d_rcu from o... |
828 |
hlist_for_each_entry(alias, &inode->i_dentry, d_u.d_alias) { |
da5029563 fs: dcache scale ... |
829 |
spin_lock(&alias->d_lock); |
1da177e4c Linux-2.6.12-rc2 |
830 |
if (S_ISDIR(inode->i_mode) || !d_unhashed(alias)) { |
21c0d8fdd [PATCH] knfsd: cl... |
831 |
if (IS_ROOT(alias) && |
da5029563 fs: dcache scale ... |
832 |
(alias->d_flags & DCACHE_DISCONNECTED)) { |
1da177e4c Linux-2.6.12-rc2 |
833 |
discon_alias = alias; |
52ed46f0f dcache: remove un... |
834 |
} else { |
dc0474be3 fs: dcache ration... |
835 |
__dget_dlock(alias); |
da5029563 fs: dcache scale ... |
836 837 838 839 840 841 842 843 844 845 |
spin_unlock(&alias->d_lock); return alias; } } spin_unlock(&alias->d_lock); } if (discon_alias) { alias = discon_alias; spin_lock(&alias->d_lock); if (S_ISDIR(inode->i_mode) || !d_unhashed(alias)) { |
8d80d7dab dcache: d_find_al... |
846 847 848 |
__dget_dlock(alias); spin_unlock(&alias->d_lock); return alias; |
1da177e4c Linux-2.6.12-rc2 |
849 |
} |
da5029563 fs: dcache scale ... |
850 851 |
spin_unlock(&alias->d_lock); goto again; |
1da177e4c Linux-2.6.12-rc2 |
852 |
} |
da5029563 fs: dcache scale ... |
853 |
return NULL; |
1da177e4c Linux-2.6.12-rc2 |
854 |
} |
da5029563 fs: dcache scale ... |
855 |
struct dentry *d_find_alias(struct inode *inode) |
1da177e4c Linux-2.6.12-rc2 |
856 |
{ |
214fda1f6 [PATCH] Optimise ... |
857 |
struct dentry *de = NULL; |
b3d9b7a3c vfs: switch i_den... |
858 |
if (!hlist_empty(&inode->i_dentry)) { |
873feea09 fs: dcache per-in... |
859 |
spin_lock(&inode->i_lock); |
52ed46f0f dcache: remove un... |
860 |
de = __d_find_alias(inode); |
873feea09 fs: dcache per-in... |
861 |
spin_unlock(&inode->i_lock); |
214fda1f6 [PATCH] Optimise ... |
862 |
} |
1da177e4c Linux-2.6.12-rc2 |
863 864 |
return de; } |
ec4f86059 fs/dcache.c: Codi... |
865 |
EXPORT_SYMBOL(d_find_alias); |
1da177e4c Linux-2.6.12-rc2 |
866 867 868 869 870 871 872 |
/* * Try to kill dentries associated with this inode. * WARNING: you must own a reference to inode. */ void d_prune_aliases(struct inode *inode) { |
0cdca3f98 [PATCH] janitor: ... |
873 |
struct dentry *dentry; |
1da177e4c Linux-2.6.12-rc2 |
874 |
restart: |
873feea09 fs: dcache per-in... |
875 |
spin_lock(&inode->i_lock); |
946e51f2b move d_rcu from o... |
876 |
hlist_for_each_entry(dentry, &inode->i_dentry, d_u.d_alias) { |
1da177e4c Linux-2.6.12-rc2 |
877 |
spin_lock(&dentry->d_lock); |
98474236f vfs: make the den... |
878 |
if (!dentry->d_lockref.count) { |
29355c390 d_prune_alias(): ... |
879 880 881 |
struct dentry *parent = lock_parent(dentry); if (likely(!dentry->d_lockref.count)) { __dentry_kill(dentry); |
4a7795d35 vfs: fix referenc... |
882 |
dput(parent); |
29355c390 d_prune_alias(): ... |
883 884 885 886 |
goto restart; } if (parent) spin_unlock(&parent->d_lock); |
1da177e4c Linux-2.6.12-rc2 |
887 888 889 |
} spin_unlock(&dentry->d_lock); } |
873feea09 fs: dcache per-in... |
890 |
spin_unlock(&inode->i_lock); |
1da177e4c Linux-2.6.12-rc2 |
891 |
} |
ec4f86059 fs/dcache.c: Codi... |
892 |
EXPORT_SYMBOL(d_prune_aliases); |
1da177e4c Linux-2.6.12-rc2 |
893 |
|
3049cfe24 fs: split __shrin... |
894 |
static void shrink_dentry_list(struct list_head *list) |
1da177e4c Linux-2.6.12-rc2 |
895 |
{ |
5c47e6d0a fold try_prune_on... |
896 |
struct dentry *dentry, *parent; |
da3bbdd46 fix soft lock up ... |
897 |
|
60942f2f2 dcache: don't nee... |
898 |
while (!list_empty(list)) { |
ff2fde992 expand dentry_kil... |
899 |
struct inode *inode; |
60942f2f2 dcache: don't nee... |
900 |
dentry = list_entry(list->prev, struct dentry, d_lru); |
ec33679d7 fs: use RCU in sh... |
901 |
spin_lock(&dentry->d_lock); |
046b961b4 shrink_dentry_lis... |
902 |
parent = lock_parent(dentry); |
1da177e4c Linux-2.6.12-rc2 |
903 |
/* |
dd1f6b2e4 dcache: remove de... |
904 905 906 907 |
* The dispose list is isolated and dentries are not accounted * to the LRU here, so we can simply remove it from the list * here regardless of whether it is referenced or not. */ |
89dc77bcd vfs: fix dentry L... |
908 |
d_shrink_del(dentry); |
dd1f6b2e4 dcache: remove de... |
909 910 |
/* |
1da177e4c Linux-2.6.12-rc2 |
911 |
* We found an inuse dentry which was not removed from |
dd1f6b2e4 dcache: remove de... |
912 |
* the LRU because of laziness during lookup. Do not free it. |
1da177e4c Linux-2.6.12-rc2 |
913 |
*/ |
360f54796 dcache: let the d... |
914 |
if (dentry->d_lockref.count > 0) { |
da3bbdd46 fix soft lock up ... |
915 |
spin_unlock(&dentry->d_lock); |
046b961b4 shrink_dentry_lis... |
916 917 |
if (parent) spin_unlock(&parent->d_lock); |
1da177e4c Linux-2.6.12-rc2 |
918 919 |
continue; } |
77812a1ef fs: consolidate d... |
920 |
|
64fd72e0a lift the "already... |
921 922 923 924 |
if (unlikely(dentry->d_flags & DCACHE_DENTRY_KILLED)) { bool can_free = dentry->d_flags & DCACHE_MAY_FREE; spin_unlock(&dentry->d_lock); |
046b961b4 shrink_dentry_lis... |
925 926 |
if (parent) spin_unlock(&parent->d_lock); |
64fd72e0a lift the "already... |
927 928 929 930 |
if (can_free) dentry_free(dentry); continue; } |
ff2fde992 expand dentry_kil... |
931 932 |
inode = dentry->d_inode; if (inode && unlikely(!spin_trylock(&inode->i_lock))) { |
89dc77bcd vfs: fix dentry L... |
933 |
d_shrink_add(dentry, list); |
dd1f6b2e4 dcache: remove de... |
934 |
spin_unlock(&dentry->d_lock); |
046b961b4 shrink_dentry_lis... |
935 936 |
if (parent) spin_unlock(&parent->d_lock); |
5c47e6d0a fold try_prune_on... |
937 |
continue; |
dd1f6b2e4 dcache: remove de... |
938 |
} |
ff2fde992 expand dentry_kil... |
939 |
|
ff2fde992 expand dentry_kil... |
940 |
__dentry_kill(dentry); |
046b961b4 shrink_dentry_lis... |
941 |
|
5c47e6d0a fold try_prune_on... |
942 943 944 945 946 947 948 |
/* * We need to prune ancestors too. This is necessary to prevent * quadratic behavior of shrink_dcache_parent(), but is also * expected to be beneficial in reducing dentry cache * fragmentation. */ dentry = parent; |
b2b80195d dealing with the ... |
949 950 951 952 953 954 955 956 957 958 959 960 961 962 963 964 965 966 967 968 |
while (dentry && !lockref_put_or_lock(&dentry->d_lockref)) { parent = lock_parent(dentry); if (dentry->d_lockref.count != 1) { dentry->d_lockref.count--; spin_unlock(&dentry->d_lock); if (parent) spin_unlock(&parent->d_lock); break; } inode = dentry->d_inode; /* can't be NULL */ if (unlikely(!spin_trylock(&inode->i_lock))) { spin_unlock(&dentry->d_lock); if (parent) spin_unlock(&parent->d_lock); cpu_relax(); continue; } __dentry_kill(dentry); dentry = parent; } |
da3bbdd46 fix soft lock up ... |
969 |
} |
3049cfe24 fs: split __shrin... |
970 |
} |
3f97b1632 list_lru: add hel... |
971 972 |
static enum lru_status dentry_lru_isolate(struct list_head *item, struct list_lru_one *lru, spinlock_t *lru_lock, void *arg) |
f60415675 dcache: convert t... |
973 974 975 976 977 978 979 980 981 982 983 984 985 986 987 988 989 990 991 |
{ struct list_head *freeable = arg; struct dentry *dentry = container_of(item, struct dentry, d_lru); /* * we are inverting the lru lock/dentry->d_lock here, * so use a trylock. If we fail to get the lock, just skip * it */ if (!spin_trylock(&dentry->d_lock)) return LRU_SKIP; /* * Referenced dentries are still in use. If they have active * counts, just remove them from the LRU. Otherwise give them * another pass through the LRU. */ if (dentry->d_lockref.count) { |
3f97b1632 list_lru: add hel... |
992 |
d_lru_isolate(lru, dentry); |
f60415675 dcache: convert t... |
993 994 995 996 997 998 999 1000 1001 1002 1003 1004 1005 1006 1007 1008 1009 1010 1011 1012 1013 1014 1015 1016 1017 1018 1019 1020 1021 |
spin_unlock(&dentry->d_lock); return LRU_REMOVED; } if (dentry->d_flags & DCACHE_REFERENCED) { dentry->d_flags &= ~DCACHE_REFERENCED; spin_unlock(&dentry->d_lock); /* * The list move itself will be made by the common LRU code. At * this point, we've dropped the dentry->d_lock but keep the * lru lock. This is safe to do, since every list movement is * protected by the lru lock even if both locks are held. * * This is guaranteed by the fact that all LRU management * functions are intermediated by the LRU API calls like * list_lru_add and list_lru_del. List movement in this file * only ever occur through this functions or through callbacks * like this one, that are called from the LRU API. * * The only exceptions to this are functions like * shrink_dentry_list, and code that first checks for the * DCACHE_SHRINK_LIST flag. Those are guaranteed to be * operating only with stack provided lists after they are * properly isolated from the main list. It is thus, always a * local access. */ return LRU_ROTATE; } |
3f97b1632 list_lru: add hel... |
1022 |
d_lru_shrink_move(lru, dentry, freeable); |
f60415675 dcache: convert t... |
1023 1024 1025 1026 |
spin_unlock(&dentry->d_lock); return LRU_REMOVED; } |
3049cfe24 fs: split __shrin... |
1027 |
/** |
b48f03b31 dcache: use a dis... |
1028 1029 |
* prune_dcache_sb - shrink the dcache * @sb: superblock |
503c358cf list_lru: introdu... |
1030 |
* @sc: shrink control, passed to list_lru_shrink_walk() |
b48f03b31 dcache: use a dis... |
1031 |
* |
503c358cf list_lru: introdu... |
1032 1033 |
* Attempt to shrink the superblock dcache LRU by @sc->nr_to_scan entries. This * is done when we need more memory and called from the superblock shrinker |
b48f03b31 dcache: use a dis... |
1034 |
* function. |
3049cfe24 fs: split __shrin... |
1035 |
* |
b48f03b31 dcache: use a dis... |
1036 1037 |
* This function may fail to free any resources if all the dentries are in * use. |
3049cfe24 fs: split __shrin... |
1038 |
*/ |
503c358cf list_lru: introdu... |
1039 |
long prune_dcache_sb(struct super_block *sb, struct shrink_control *sc) |
3049cfe24 fs: split __shrin... |
1040 |
{ |
f60415675 dcache: convert t... |
1041 1042 |
LIST_HEAD(dispose); long freed; |
3049cfe24 fs: split __shrin... |
1043 |
|
503c358cf list_lru: introdu... |
1044 1045 |
freed = list_lru_shrink_walk(&sb->s_dentry_lru, sc, dentry_lru_isolate, &dispose); |
f60415675 dcache: convert t... |
1046 |
shrink_dentry_list(&dispose); |
0a234c6dc shrinker: convert... |
1047 |
return freed; |
da3bbdd46 fix soft lock up ... |
1048 |
} |
230445078 fs: dcache scale lru |
1049 |
|
4e717f5c1 list_lru: remove ... |
1050 |
static enum lru_status dentry_lru_isolate_shrink(struct list_head *item, |
3f97b1632 list_lru: add hel... |
1051 |
struct list_lru_one *lru, spinlock_t *lru_lock, void *arg) |
dd1f6b2e4 dcache: remove de... |
1052 |
{ |
4e717f5c1 list_lru: remove ... |
1053 1054 |
struct list_head *freeable = arg; struct dentry *dentry = container_of(item, struct dentry, d_lru); |
dd1f6b2e4 dcache: remove de... |
1055 |
|
4e717f5c1 list_lru: remove ... |
1056 1057 1058 1059 1060 1061 1062 |
/* * we are inverting the lru lock/dentry->d_lock here, * so use a trylock. If we fail to get the lock, just skip * it */ if (!spin_trylock(&dentry->d_lock)) return LRU_SKIP; |
3f97b1632 list_lru: add hel... |
1063 |
d_lru_shrink_move(lru, dentry, freeable); |
4e717f5c1 list_lru: remove ... |
1064 |
spin_unlock(&dentry->d_lock); |
ec33679d7 fs: use RCU in sh... |
1065 |
|
4e717f5c1 list_lru: remove ... |
1066 |
return LRU_REMOVED; |
da3bbdd46 fix soft lock up ... |
1067 |
} |
4e717f5c1 list_lru: remove ... |
1068 |
|
da3bbdd46 fix soft lock up ... |
1069 |
/** |
1da177e4c Linux-2.6.12-rc2 |
1070 1071 1072 |
* shrink_dcache_sb - shrink dcache for a superblock * @sb: superblock * |
3049cfe24 fs: split __shrin... |
1073 1074 |
* Shrink the dcache for the specified super block. This is used to free * the dcache before unmounting a file system. |
1da177e4c Linux-2.6.12-rc2 |
1075 |
*/ |
3049cfe24 fs: split __shrin... |
1076 |
void shrink_dcache_sb(struct super_block *sb) |
1da177e4c Linux-2.6.12-rc2 |
1077 |
{ |
4e717f5c1 list_lru: remove ... |
1078 1079 1080 1081 1082 1083 1084 |
long freed; do { LIST_HEAD(dispose); freed = list_lru_walk(&sb->s_dentry_lru, dentry_lru_isolate_shrink, &dispose, UINT_MAX); |
3049cfe24 fs: split __shrin... |
1085 |
|
4e717f5c1 list_lru: remove ... |
1086 1087 1088 |
this_cpu_sub(nr_dentry_unused, freed); shrink_dentry_list(&dispose); } while (freed > 0); |
1da177e4c Linux-2.6.12-rc2 |
1089 |
} |
ec4f86059 fs/dcache.c: Codi... |
1090 |
EXPORT_SYMBOL(shrink_dcache_sb); |
1da177e4c Linux-2.6.12-rc2 |
1091 |
|
db14fc3ab vfs: add d_walk() |
1092 1093 1094 1095 1096 1097 1098 1099 1100 1101 1102 1103 1104 |
/** * enum d_walk_ret - action to talke during tree walk * @D_WALK_CONTINUE: contrinue walk * @D_WALK_QUIT: quit walk * @D_WALK_NORETRY: quit when retry is needed * @D_WALK_SKIP: skip this dentry and its children */ enum d_walk_ret { D_WALK_CONTINUE, D_WALK_QUIT, D_WALK_NORETRY, D_WALK_SKIP, }; |
c826cb7df dcache.c: create ... |
1105 |
|
1da177e4c Linux-2.6.12-rc2 |
1106 |
/** |
db14fc3ab vfs: add d_walk() |
1107 1108 1109 1110 1111 |
* d_walk - walk the dentry tree * @parent: start of walk * @data: data passed to @enter() and @finish() * @enter: callback when first entering the dentry * @finish: callback when successfully finished the walk |
1da177e4c Linux-2.6.12-rc2 |
1112 |
* |
db14fc3ab vfs: add d_walk() |
1113 |
* The @enter() and @finish() callbacks are called with d_lock held. |
1da177e4c Linux-2.6.12-rc2 |
1114 |
*/ |
db14fc3ab vfs: add d_walk() |
1115 1116 1117 |
static void d_walk(struct dentry *parent, void *data, enum d_walk_ret (*enter)(void *, struct dentry *), void (*finish)(void *)) |
1da177e4c Linux-2.6.12-rc2 |
1118 |
{ |
949854d02 fs: Use rename lo... |
1119 |
struct dentry *this_parent; |
1da177e4c Linux-2.6.12-rc2 |
1120 |
struct list_head *next; |
48f5ec21d split read_seqret... |
1121 |
unsigned seq = 0; |
db14fc3ab vfs: add d_walk() |
1122 1123 |
enum d_walk_ret ret; bool retry = true; |
949854d02 fs: Use rename lo... |
1124 |
|
58db63d08 fs: dcache avoid ... |
1125 |
again: |
48f5ec21d split read_seqret... |
1126 |
read_seqbegin_or_lock(&rename_lock, &seq); |
58db63d08 fs: dcache avoid ... |
1127 |
this_parent = parent; |
2fd6b7f50 fs: dcache scale ... |
1128 |
spin_lock(&this_parent->d_lock); |
db14fc3ab vfs: add d_walk() |
1129 1130 1131 1132 1133 1134 1135 1136 1137 1138 1139 1140 |
ret = enter(data, this_parent); switch (ret) { case D_WALK_CONTINUE: break; case D_WALK_QUIT: case D_WALK_SKIP: goto out_unlock; case D_WALK_NORETRY: retry = false; break; } |
1da177e4c Linux-2.6.12-rc2 |
1141 1142 1143 1144 1145 |
repeat: next = this_parent->d_subdirs.next; resume: while (next != &this_parent->d_subdirs) { struct list_head *tmp = next; |
946e51f2b move d_rcu from o... |
1146 |
struct dentry *dentry = list_entry(tmp, struct dentry, d_child); |
1da177e4c Linux-2.6.12-rc2 |
1147 |
next = tmp->next; |
2fd6b7f50 fs: dcache scale ... |
1148 |
|
ba65dc5ef much milder d_wal... |
1149 1150 |
if (unlikely(dentry->d_flags & DCACHE_DENTRY_CURSOR)) continue; |
2fd6b7f50 fs: dcache scale ... |
1151 |
spin_lock_nested(&dentry->d_lock, DENTRY_D_LOCK_NESTED); |
db14fc3ab vfs: add d_walk() |
1152 1153 1154 1155 1156 1157 |
ret = enter(data, dentry); switch (ret) { case D_WALK_CONTINUE: break; case D_WALK_QUIT: |
2fd6b7f50 fs: dcache scale ... |
1158 |
spin_unlock(&dentry->d_lock); |
db14fc3ab vfs: add d_walk() |
1159 1160 1161 1162 1163 1164 1165 |
goto out_unlock; case D_WALK_NORETRY: retry = false; break; case D_WALK_SKIP: spin_unlock(&dentry->d_lock); continue; |
2fd6b7f50 fs: dcache scale ... |
1166 |
} |
db14fc3ab vfs: add d_walk() |
1167 |
|
1da177e4c Linux-2.6.12-rc2 |
1168 |
if (!list_empty(&dentry->d_subdirs)) { |
2fd6b7f50 fs: dcache scale ... |
1169 1170 |
spin_unlock(&this_parent->d_lock); spin_release(&dentry->d_lock.dep_map, 1, _RET_IP_); |
1da177e4c Linux-2.6.12-rc2 |
1171 |
this_parent = dentry; |
2fd6b7f50 fs: dcache scale ... |
1172 |
spin_acquire(&this_parent->d_lock.dep_map, 0, 1, _RET_IP_); |
1da177e4c Linux-2.6.12-rc2 |
1173 1174 |
goto repeat; } |
2fd6b7f50 fs: dcache scale ... |
1175 |
spin_unlock(&dentry->d_lock); |
1da177e4c Linux-2.6.12-rc2 |
1176 1177 1178 1179 |
} /* * All done at this level ... ascend and resume the search. */ |
ca5358ef7 deal with deadloc... |
1180 1181 |
rcu_read_lock(); ascend: |
1da177e4c Linux-2.6.12-rc2 |
1182 |
if (this_parent != parent) { |
c826cb7df dcache.c: create ... |
1183 |
struct dentry *child = this_parent; |
31dec1327 fold try_to_ascen... |
1184 |
this_parent = child->d_parent; |
31dec1327 fold try_to_ascen... |
1185 1186 |
spin_unlock(&child->d_lock); spin_lock(&this_parent->d_lock); |
ca5358ef7 deal with deadloc... |
1187 1188 |
/* might go back up the wrong parent if we have had a rename. */ if (need_seqretry(&rename_lock, seq)) |
949854d02 fs: Use rename lo... |
1189 |
goto rename_retry; |
2159184ea d_walk() might sk... |
1190 1191 1192 |
/* go into the first sibling still alive */ do { next = child->d_child.next; |
ca5358ef7 deal with deadloc... |
1193 1194 1195 |
if (next == &this_parent->d_subdirs) goto ascend; child = list_entry(next, struct dentry, d_child); |
2159184ea d_walk() might sk... |
1196 |
} while (unlikely(child->d_flags & DCACHE_DENTRY_KILLED)); |
31dec1327 fold try_to_ascen... |
1197 |
rcu_read_unlock(); |
1da177e4c Linux-2.6.12-rc2 |
1198 1199 |
goto resume; } |
ca5358ef7 deal with deadloc... |
1200 |
if (need_seqretry(&rename_lock, seq)) |
949854d02 fs: Use rename lo... |
1201 |
goto rename_retry; |
ca5358ef7 deal with deadloc... |
1202 |
rcu_read_unlock(); |
db14fc3ab vfs: add d_walk() |
1203 1204 1205 1206 1207 |
if (finish) finish(data); out_unlock: spin_unlock(&this_parent->d_lock); |
48f5ec21d split read_seqret... |
1208 |
done_seqretry(&rename_lock, seq); |
db14fc3ab vfs: add d_walk() |
1209 |
return; |
58db63d08 fs: dcache avoid ... |
1210 1211 |
rename_retry: |
ca5358ef7 deal with deadloc... |
1212 1213 1214 |
spin_unlock(&this_parent->d_lock); rcu_read_unlock(); BUG_ON(seq & 1); |
db14fc3ab vfs: add d_walk() |
1215 1216 |
if (!retry) return; |
48f5ec21d split read_seqret... |
1217 |
seq = 1; |
58db63d08 fs: dcache avoid ... |
1218 |
goto again; |
1da177e4c Linux-2.6.12-rc2 |
1219 |
} |
db14fc3ab vfs: add d_walk() |
1220 1221 1222 1223 1224 1225 |
/* * Search for at least 1 mount point in the dentry's subdirs. * We descend to the next level whenever the d_subdirs * list is non-empty and continue searching. */ |
db14fc3ab vfs: add d_walk() |
1226 1227 1228 1229 1230 1231 1232 1233 1234 |
static enum d_walk_ret check_mount(void *data, struct dentry *dentry) { int *ret = data; if (d_mountpoint(dentry)) { *ret = 1; return D_WALK_QUIT; } return D_WALK_CONTINUE; } |
69c88dc7d vfs: fix new kern... |
1235 1236 1237 1238 1239 1240 1241 |
/** * have_submounts - check for mounts over a dentry * @parent: dentry to check. * * Return true if the parent or its subdirectories contain * a mount point */ |
db14fc3ab vfs: add d_walk() |
1242 1243 1244 1245 1246 1247 1248 1249 |
int have_submounts(struct dentry *parent) { int ret = 0; d_walk(parent, &ret, check_mount, NULL); return ret; } |
ec4f86059 fs/dcache.c: Codi... |
1250 |
EXPORT_SYMBOL(have_submounts); |
1da177e4c Linux-2.6.12-rc2 |
1251 1252 |
/* |
eed810076 vfs: check unlink... |
1253 1254 1255 1256 |
* Called by mount code to set a mountpoint and check if the mountpoint is * reachable (e.g. NFS can unhash a directory dentry and then the complete * subtree can become unreachable). * |
1ffe46d11 vfs: Merge check_... |
1257 |
* Only one of d_invalidate() and d_set_mounted() must succeed. For |
eed810076 vfs: check unlink... |
1258 1259 1260 1261 1262 1263 1264 1265 |
* this reason take rename_lock and d_lock on dentry and ancestors. */ int d_set_mounted(struct dentry *dentry) { struct dentry *p; int ret = -ENOENT; write_seqlock(&rename_lock); for (p = dentry->d_parent; !IS_ROOT(p); p = p->d_parent) { |
1ffe46d11 vfs: Merge check_... |
1266 |
/* Need exclusion wrt. d_invalidate() */ |
eed810076 vfs: check unlink... |
1267 1268 1269 1270 1271 1272 1273 1274 1275 |
spin_lock(&p->d_lock); if (unlikely(d_unhashed(p))) { spin_unlock(&p->d_lock); goto out; } spin_unlock(&p->d_lock); } spin_lock(&dentry->d_lock); if (!d_unlinked(dentry)) { |
1a62a0f76 mnt: Protect the ... |
1276 1277 1278 1279 1280 |
ret = -EBUSY; if (!d_mountpoint(dentry)) { dentry->d_flags |= DCACHE_MOUNTED; ret = 0; } |
eed810076 vfs: check unlink... |
1281 1282 1283 1284 1285 1286 1287 1288 |
} spin_unlock(&dentry->d_lock); out: write_sequnlock(&rename_lock); return ret; } /* |
fd5179094 trivial select_pa... |
1289 |
* Search the dentry child list of the specified parent, |
1da177e4c Linux-2.6.12-rc2 |
1290 1291 1292 1293 1294 1295 1296 1297 1298 1299 1300 1301 |
* and move any unused dentries to the end of the unused * list for prune_dcache(). We descend to the next level * whenever the d_subdirs list is non-empty and continue * searching. * * It returns zero iff there are no unused children, * otherwise it returns the number of children moved to * the end of the unused list. This may not be the total * number of unused children, because select_parent can * drop the lock and return early due to latency * constraints. */ |
1da177e4c Linux-2.6.12-rc2 |
1302 |
|
db14fc3ab vfs: add d_walk() |
1303 1304 1305 1306 1307 |
struct select_data { struct dentry *start; struct list_head dispose; int found; }; |
230445078 fs: dcache scale lru |
1308 |
|
db14fc3ab vfs: add d_walk() |
1309 1310 1311 1312 |
static enum d_walk_ret select_collect(void *_data, struct dentry *dentry) { struct select_data *data = _data; enum d_walk_ret ret = D_WALK_CONTINUE; |
1da177e4c Linux-2.6.12-rc2 |
1313 |
|
db14fc3ab vfs: add d_walk() |
1314 1315 |
if (data->start == dentry) goto out; |
2fd6b7f50 fs: dcache scale ... |
1316 |
|
fe91522a7 don't remove from... |
1317 |
if (dentry->d_flags & DCACHE_SHRINK_LIST) { |
db14fc3ab vfs: add d_walk() |
1318 |
data->found++; |
fe91522a7 don't remove from... |
1319 1320 1321 1322 1323 1324 1325 |
} else { if (dentry->d_flags & DCACHE_LRU_LIST) d_lru_del(dentry); if (!dentry->d_lockref.count) { d_shrink_add(dentry, &data->dispose); data->found++; } |
1da177e4c Linux-2.6.12-rc2 |
1326 |
} |
db14fc3ab vfs: add d_walk() |
1327 1328 1329 1330 1331 |
/* * We can return to the caller if we have found some (this * ensures forward progress). We'll be coming back to find * the rest. */ |
fe91522a7 don't remove from... |
1332 1333 |
if (!list_empty(&data->dispose)) ret = need_resched() ? D_WALK_QUIT : D_WALK_NORETRY; |
1da177e4c Linux-2.6.12-rc2 |
1334 |
out: |
db14fc3ab vfs: add d_walk() |
1335 |
return ret; |
1da177e4c Linux-2.6.12-rc2 |
1336 1337 1338 1339 1340 1341 1342 1343 |
} /** * shrink_dcache_parent - prune dcache * @parent: parent of entries to prune * * Prune the dcache to remove unused children of the parent dentry. */ |
db14fc3ab vfs: add d_walk() |
1344 |
void shrink_dcache_parent(struct dentry *parent) |
1da177e4c Linux-2.6.12-rc2 |
1345 |
{ |
db14fc3ab vfs: add d_walk() |
1346 1347 |
for (;;) { struct select_data data; |
1da177e4c Linux-2.6.12-rc2 |
1348 |
|
db14fc3ab vfs: add d_walk() |
1349 1350 1351 1352 1353 1354 1355 1356 1357 |
INIT_LIST_HEAD(&data.dispose); data.start = parent; data.found = 0; d_walk(parent, &data, select_collect, NULL); if (!data.found) break; shrink_dentry_list(&data.dispose); |
421348f1c fs/dcache.c: add ... |
1358 1359 |
cond_resched(); } |
1da177e4c Linux-2.6.12-rc2 |
1360 |
} |
ec4f86059 fs/dcache.c: Codi... |
1361 |
EXPORT_SYMBOL(shrink_dcache_parent); |
1da177e4c Linux-2.6.12-rc2 |
1362 |
|
9c8c10e26 more graceful rec... |
1363 |
static enum d_walk_ret umount_check(void *_data, struct dentry *dentry) |
42c326082 switch shrink_dca... |
1364 |
{ |
9c8c10e26 more graceful rec... |
1365 1366 1367 |
/* it has busy descendents; complain about those instead */ if (!list_empty(&dentry->d_subdirs)) return D_WALK_CONTINUE; |
42c326082 switch shrink_dca... |
1368 |
|
9c8c10e26 more graceful rec... |
1369 1370 1371 1372 1373 1374 1375 |
/* root with refcount 1 is fine */ if (dentry == _data && dentry->d_lockref.count == 1) return D_WALK_CONTINUE; printk(KERN_ERR "BUG: Dentry %p{i=%lx,n=%pd} " " still in use (%d) [unmount of %s %s] ", |
42c326082 switch shrink_dca... |
1376 1377 1378 |
dentry, dentry->d_inode ? dentry->d_inode->i_ino : 0UL, |
9c8c10e26 more graceful rec... |
1379 |
dentry, |
42c326082 switch shrink_dca... |
1380 1381 1382 |
dentry->d_lockref.count, dentry->d_sb->s_type->name, dentry->d_sb->s_id); |
9c8c10e26 more graceful rec... |
1383 1384 1385 1386 1387 1388 1389 1390 1391 1392 |
WARN_ON(1); return D_WALK_CONTINUE; } static void do_one_tree(struct dentry *dentry) { shrink_dcache_parent(dentry); d_walk(dentry, dentry, umount_check, NULL); d_drop(dentry); dput(dentry); |
42c326082 switch shrink_dca... |
1393 1394 1395 1396 1397 1398 1399 1400 |
} /* * destroy the dentries attached to a superblock on unmounting */ void shrink_dcache_for_umount(struct super_block *sb) { struct dentry *dentry; |
9c8c10e26 more graceful rec... |
1401 |
WARN(down_read_trylock(&sb->s_umount), "s_umount should've been locked"); |
42c326082 switch shrink_dca... |
1402 1403 1404 |
dentry = sb->s_root; sb->s_root = NULL; |
9c8c10e26 more graceful rec... |
1405 |
do_one_tree(dentry); |
42c326082 switch shrink_dca... |
1406 1407 |
while (!hlist_bl_empty(&sb->s_anon)) { |
9c8c10e26 more graceful rec... |
1408 1409 |
dentry = dget(hlist_bl_entry(hlist_bl_first(&sb->s_anon), struct dentry, d_hash)); do_one_tree(dentry); |
42c326082 switch shrink_dca... |
1410 1411 |
} } |
8ed936b56 vfs: Lazily remov... |
1412 1413 1414 1415 1416 |
struct detach_data { struct select_data select; struct dentry *mountpoint; }; static enum d_walk_ret detach_and_collect(void *_data, struct dentry *dentry) |
848ac114e vfs: check submou... |
1417 |
{ |
8ed936b56 vfs: Lazily remov... |
1418 |
struct detach_data *data = _data; |
848ac114e vfs: check submou... |
1419 1420 |
if (d_mountpoint(dentry)) { |
8ed936b56 vfs: Lazily remov... |
1421 1422 |
__dget_dlock(dentry); data->mountpoint = dentry; |
848ac114e vfs: check submou... |
1423 1424 |
return D_WALK_QUIT; } |
8ed936b56 vfs: Lazily remov... |
1425 |
return select_collect(&data->select, dentry); |
848ac114e vfs: check submou... |
1426 1427 1428 1429 |
} static void check_and_drop(void *_data) { |
8ed936b56 vfs: Lazily remov... |
1430 |
struct detach_data *data = _data; |
848ac114e vfs: check submou... |
1431 |
|
8ed936b56 vfs: Lazily remov... |
1432 1433 |
if (!data->mountpoint && !data->select.found) __d_drop(data->select.start); |
848ac114e vfs: check submou... |
1434 1435 1436 |
} /** |
1ffe46d11 vfs: Merge check_... |
1437 1438 1439 |
* d_invalidate - detach submounts, prune dcache, and drop * @dentry: dentry to invalidate (aka detach, prune and drop) * |
1ffe46d11 vfs: Merge check_... |
1440 |
* no dcache lock. |
848ac114e vfs: check submou... |
1441 |
* |
8ed936b56 vfs: Lazily remov... |
1442 1443 1444 |
* The final d_drop is done as an atomic operation relative to * rename_lock ensuring there are no races with d_set_mounted. This * ensures there are no unhashed dentries on the path to a mountpoint. |
848ac114e vfs: check submou... |
1445 |
*/ |
5542aa2fa vfs: Make d_inval... |
1446 |
void d_invalidate(struct dentry *dentry) |
848ac114e vfs: check submou... |
1447 |
{ |
1ffe46d11 vfs: Merge check_... |
1448 1449 1450 1451 1452 1453 |
/* * If it's already been dropped, return OK. */ spin_lock(&dentry->d_lock); if (d_unhashed(dentry)) { spin_unlock(&dentry->d_lock); |
5542aa2fa vfs: Make d_inval... |
1454 |
return; |
1ffe46d11 vfs: Merge check_... |
1455 1456 |
} spin_unlock(&dentry->d_lock); |
848ac114e vfs: check submou... |
1457 1458 1459 |
/* Negative dentries can be dropped without further checks */ if (!dentry->d_inode) { d_drop(dentry); |
5542aa2fa vfs: Make d_inval... |
1460 |
return; |
848ac114e vfs: check submou... |
1461 1462 1463 |
} for (;;) { |
8ed936b56 vfs: Lazily remov... |
1464 |
struct detach_data data; |
848ac114e vfs: check submou... |
1465 |
|
8ed936b56 vfs: Lazily remov... |
1466 1467 1468 1469 1470 1471 |
data.mountpoint = NULL; INIT_LIST_HEAD(&data.select.dispose); data.select.start = dentry; data.select.found = 0; d_walk(dentry, &data, detach_and_collect, check_and_drop); |
848ac114e vfs: check submou... |
1472 |
|
8ed936b56 vfs: Lazily remov... |
1473 1474 |
if (data.select.found) shrink_dentry_list(&data.select.dispose); |
848ac114e vfs: check submou... |
1475 |
|
8ed936b56 vfs: Lazily remov... |
1476 1477 1478 1479 |
if (data.mountpoint) { detach_mounts(data.mountpoint); dput(data.mountpoint); } |
848ac114e vfs: check submou... |
1480 |
|
8ed936b56 vfs: Lazily remov... |
1481 |
if (!data.mountpoint && !data.select.found) |
848ac114e vfs: check submou... |
1482 1483 1484 1485 |
break; cond_resched(); } |
848ac114e vfs: check submou... |
1486 |
} |
1ffe46d11 vfs: Merge check_... |
1487 |
EXPORT_SYMBOL(d_invalidate); |
848ac114e vfs: check submou... |
1488 |
|
1da177e4c Linux-2.6.12-rc2 |
1489 |
/** |
a4464dbc0 Make ->d_sb assig... |
1490 1491 |
* __d_alloc - allocate a dcache entry * @sb: filesystem it will belong to |
1da177e4c Linux-2.6.12-rc2 |
1492 1493 1494 1495 1496 1497 1498 |
* @name: qstr of the name * * Allocates a dentry. It returns %NULL if there is insufficient memory * available. On a success the dentry is returned. The name passed in is * copied and the copy passed in may be reused after this call. */ |
a4464dbc0 Make ->d_sb assig... |
1499 |
struct dentry *__d_alloc(struct super_block *sb, const struct qstr *name) |
1da177e4c Linux-2.6.12-rc2 |
1500 1501 1502 |
{ struct dentry *dentry; char *dname; |
285b102d3 vfs: new d_init m... |
1503 |
int err; |
1da177e4c Linux-2.6.12-rc2 |
1504 |
|
e12ba74d8 Group short-lived... |
1505 |
dentry = kmem_cache_alloc(dentry_cache, GFP_KERNEL); |
1da177e4c Linux-2.6.12-rc2 |
1506 1507 |
if (!dentry) return NULL; |
6326c71fd vfs: be even more... |
1508 1509 1510 1511 1512 1513 1514 |
/* * We guarantee that the inline name is always NUL-terminated. * This way the memcpy() done by the name switching in rename * will still always have a NUL at the end, even if we might * be overwriting an internal NUL character */ dentry->d_iname[DNAME_INLINE_LEN-1] = 0; |
798434bda __d_alloc(): trea... |
1515 1516 1517 1518 1519 |
if (unlikely(!name)) { static const struct qstr anon = QSTR_INIT("/", 1); name = &anon; dname = dentry->d_iname; } else if (name->len > DNAME_INLINE_LEN-1) { |
8d85b4845 Allow sharing ext... |
1520 |
size_t size = offsetof(struct external_name, name[1]); |
5d097056c kmemcg: account c... |
1521 1522 |
struct external_name *p = kmalloc(size + name->len, GFP_KERNEL_ACCOUNT); |
8d85b4845 Allow sharing ext... |
1523 |
if (!p) { |
1da177e4c Linux-2.6.12-rc2 |
1524 1525 1526 |
kmem_cache_free(dentry_cache, dentry); return NULL; } |
8d85b4845 Allow sharing ext... |
1527 1528 |
atomic_set(&p->u.count, 1); dname = p->name; |
df4c0e36f fs: dcache: manua... |
1529 1530 1531 |
if (IS_ENABLED(CONFIG_DCACHE_WORD_ACCESS)) kasan_unpoison_shadow(dname, round_up(name->len + 1, sizeof(unsigned long))); |
1da177e4c Linux-2.6.12-rc2 |
1532 1533 1534 |
} else { dname = dentry->d_iname; } |
1da177e4c Linux-2.6.12-rc2 |
1535 1536 1537 1538 1539 |
dentry->d_name.len = name->len; dentry->d_name.hash = name->hash; memcpy(dname, name->name, name->len); dname[name->len] = 0; |
6326c71fd vfs: be even more... |
1540 1541 1542 |
/* Make sure we always see the terminating NUL character */ smp_wmb(); dentry->d_name.name = dname; |
98474236f vfs: make the den... |
1543 |
dentry->d_lockref.count = 1; |
dea3667bc vfs: get rid of i... |
1544 |
dentry->d_flags = 0; |
1da177e4c Linux-2.6.12-rc2 |
1545 |
spin_lock_init(&dentry->d_lock); |
31e6b01f4 fs: rcu-walk for ... |
1546 |
seqcount_init(&dentry->d_seq); |
1da177e4c Linux-2.6.12-rc2 |
1547 |
dentry->d_inode = NULL; |
a4464dbc0 Make ->d_sb assig... |
1548 1549 |
dentry->d_parent = dentry; dentry->d_sb = sb; |
1da177e4c Linux-2.6.12-rc2 |
1550 1551 |
dentry->d_op = NULL; dentry->d_fsdata = NULL; |
ceb5bdc2d fs: dcache per-bu... |
1552 |
INIT_HLIST_BL_NODE(&dentry->d_hash); |
1da177e4c Linux-2.6.12-rc2 |
1553 1554 |
INIT_LIST_HEAD(&dentry->d_lru); INIT_LIST_HEAD(&dentry->d_subdirs); |
946e51f2b move d_rcu from o... |
1555 1556 |
INIT_HLIST_NODE(&dentry->d_u.d_alias); INIT_LIST_HEAD(&dentry->d_child); |
a4464dbc0 Make ->d_sb assig... |
1557 |
d_set_d_op(dentry, dentry->d_sb->s_d_op); |
1da177e4c Linux-2.6.12-rc2 |
1558 |
|
285b102d3 vfs: new d_init m... |
1559 1560 1561 1562 1563 1564 1565 1566 1567 |
if (dentry->d_op && dentry->d_op->d_init) { err = dentry->d_op->d_init(dentry); if (err) { if (dname_external(dentry)) kfree(external_name(dentry)); kmem_cache_free(dentry_cache, dentry); return NULL; } } |
3e880fb5e fs: use fast coun... |
1568 |
this_cpu_inc(nr_dentry); |
312d3ca85 fs: use percpu co... |
1569 |
|
1da177e4c Linux-2.6.12-rc2 |
1570 1571 |
return dentry; } |
a4464dbc0 Make ->d_sb assig... |
1572 1573 1574 1575 1576 1577 1578 1579 1580 1581 1582 1583 1584 1585 1586 |
/** * d_alloc - allocate a dcache entry * @parent: parent of entry to allocate * @name: qstr of the name * * Allocates a dentry. It returns %NULL if there is insufficient memory * available. On a success the dentry is returned. The name passed in is * copied and the copy passed in may be reused after this call. */ struct dentry *d_alloc(struct dentry * parent, const struct qstr *name) { struct dentry *dentry = __d_alloc(parent->d_sb, name); if (!dentry) return NULL; |
3d56c25e3 fix d_walk()/non-... |
1587 |
dentry->d_flags |= DCACHE_RCUACCESS; |
a4464dbc0 Make ->d_sb assig... |
1588 1589 1590 1591 1592 1593 1594 |
spin_lock(&parent->d_lock); /* * don't need child lock because it is not subject * to concurrency here */ __dget_dlock(parent); dentry->d_parent = parent; |
946e51f2b move d_rcu from o... |
1595 |
list_add(&dentry->d_child, &parent->d_subdirs); |
a4464dbc0 Make ->d_sb assig... |
1596 1597 1598 1599 |
spin_unlock(&parent->d_lock); return dentry; } |
ec4f86059 fs/dcache.c: Codi... |
1600 |
EXPORT_SYMBOL(d_alloc); |
1da177e4c Linux-2.6.12-rc2 |
1601 |
|
ba65dc5ef much milder d_wal... |
1602 1603 1604 1605 1606 1607 1608 1609 1610 |
struct dentry *d_alloc_cursor(struct dentry * parent) { struct dentry *dentry = __d_alloc(parent->d_sb, NULL); if (dentry) { dentry->d_flags |= DCACHE_RCUACCESS | DCACHE_DENTRY_CURSOR; dentry->d_parent = dget(parent); } return dentry; } |
e1a24bb0a dcache: Don't set... |
1611 1612 1613 1614 1615 1616 1617 1618 |
/** * d_alloc_pseudo - allocate a dentry (for lookup-less filesystems) * @sb: the superblock * @name: qstr of the name * * For a filesystem that just pins its dentries in memory and never * performs lookups at all, return an unhashed IS_ROOT dentry. */ |
4b936885a fs: improve scala... |
1619 1620 |
struct dentry *d_alloc_pseudo(struct super_block *sb, const struct qstr *name) { |
e1a24bb0a dcache: Don't set... |
1621 |
return __d_alloc(sb, name); |
4b936885a fs: improve scala... |
1622 1623 |
} EXPORT_SYMBOL(d_alloc_pseudo); |
1da177e4c Linux-2.6.12-rc2 |
1624 1625 1626 1627 1628 |
struct dentry *d_alloc_name(struct dentry *parent, const char *name) { struct qstr q; q.name = name; |
8387ff257 vfs: make the str... |
1629 |
q.hash_len = hashlen_string(parent, name); |
1da177e4c Linux-2.6.12-rc2 |
1630 1631 |
return d_alloc(parent, &q); } |
ef26ca97e libfs: move EXPOR... |
1632 |
EXPORT_SYMBOL(d_alloc_name); |
1da177e4c Linux-2.6.12-rc2 |
1633 |
|
fb045adb9 fs: dcache reduce... |
1634 1635 |
void d_set_d_op(struct dentry *dentry, const struct dentry_operations *op) { |
6f7f7caab Turn d_set_d_op()... |
1636 1637 |
WARN_ON_ONCE(dentry->d_op); WARN_ON_ONCE(dentry->d_flags & (DCACHE_OP_HASH | |
fb045adb9 fs: dcache reduce... |
1638 1639 |
DCACHE_OP_COMPARE | DCACHE_OP_REVALIDATE | |
ecf3d1f1a vfs: kill FS_REVA... |
1640 |
DCACHE_OP_WEAK_REVALIDATE | |
4bacc9c92 overlayfs: Make f... |
1641 |
DCACHE_OP_DELETE | |
d101a1259 fs: add file_dent... |
1642 |
DCACHE_OP_REAL)); |
fb045adb9 fs: dcache reduce... |
1643 1644 1645 1646 1647 1648 1649 1650 1651 |
dentry->d_op = op; if (!op) return; if (op->d_hash) dentry->d_flags |= DCACHE_OP_HASH; if (op->d_compare) dentry->d_flags |= DCACHE_OP_COMPARE; if (op->d_revalidate) dentry->d_flags |= DCACHE_OP_REVALIDATE; |
ecf3d1f1a vfs: kill FS_REVA... |
1652 1653 |
if (op->d_weak_revalidate) dentry->d_flags |= DCACHE_OP_WEAK_REVALIDATE; |
fb045adb9 fs: dcache reduce... |
1654 1655 |
if (op->d_delete) dentry->d_flags |= DCACHE_OP_DELETE; |
f0023bc61 vfs: add d_prune ... |
1656 1657 |
if (op->d_prune) dentry->d_flags |= DCACHE_OP_PRUNE; |
d101a1259 fs: add file_dent... |
1658 1659 |
if (op->d_real) dentry->d_flags |= DCACHE_OP_REAL; |
fb045adb9 fs: dcache reduce... |
1660 1661 1662 |
} EXPORT_SYMBOL(d_set_d_op); |
df1a085af VFS: Add a fallth... |
1663 1664 1665 1666 1667 1668 1669 1670 1671 1672 1673 1674 1675 1676 1677 |
/* * d_set_fallthru - Mark a dentry as falling through to a lower layer * @dentry - The dentry to mark * * Mark a dentry as falling through to the lower layer (as set with * d_pin_lower()). This flag may be recorded on the medium. */ void d_set_fallthru(struct dentry *dentry) { spin_lock(&dentry->d_lock); dentry->d_flags |= DCACHE_FALLTHRU; spin_unlock(&dentry->d_lock); } EXPORT_SYMBOL(d_set_fallthru); |
b18825a7c VFS: Put a small ... |
1678 1679 |
static unsigned d_flags_for_inode(struct inode *inode) { |
44bdb5e5f VFS: Split DCACHE... |
1680 |
unsigned add_flags = DCACHE_REGULAR_TYPE; |
b18825a7c VFS: Put a small ... |
1681 1682 1683 1684 1685 1686 1687 1688 1689 1690 1691 1692 |
if (!inode) return DCACHE_MISS_TYPE; if (S_ISDIR(inode->i_mode)) { add_flags = DCACHE_DIRECTORY_TYPE; if (unlikely(!(inode->i_opflags & IOP_LOOKUP))) { if (unlikely(!inode->i_op->lookup)) add_flags = DCACHE_AUTODIR_TYPE; else inode->i_opflags |= IOP_LOOKUP; } |
44bdb5e5f VFS: Split DCACHE... |
1693 1694 1695 1696 |
goto type_determined; } if (unlikely(!(inode->i_opflags & IOP_NOFOLLOW))) { |
6b2553918 replace ->follow_... |
1697 |
if (unlikely(inode->i_op->get_link)) { |
b18825a7c VFS: Put a small ... |
1698 |
add_flags = DCACHE_SYMLINK_TYPE; |
44bdb5e5f VFS: Split DCACHE... |
1699 1700 1701 |
goto type_determined; } inode->i_opflags |= IOP_NOFOLLOW; |
b18825a7c VFS: Put a small ... |
1702 |
} |
44bdb5e5f VFS: Split DCACHE... |
1703 1704 1705 1706 |
if (unlikely(!S_ISREG(inode->i_mode))) add_flags = DCACHE_SPECIAL_TYPE; type_determined: |
b18825a7c VFS: Put a small ... |
1707 1708 1709 1710 |
if (unlikely(IS_AUTOMOUNT(inode))) add_flags |= DCACHE_NEED_AUTOMOUNT; return add_flags; } |
360da9002 [PATCH vfs-2.6 3/... |
1711 1712 |
static void __d_instantiate(struct dentry *dentry, struct inode *inode) { |
b18825a7c VFS: Put a small ... |
1713 |
unsigned add_flags = d_flags_for_inode(inode); |
85c7f8104 beginning of tran... |
1714 |
WARN_ON(d_in_lookup(dentry)); |
b18825a7c VFS: Put a small ... |
1715 |
|
b23fb0a60 fs: scale inode a... |
1716 |
spin_lock(&dentry->d_lock); |
de689f5e3 don't bother with... |
1717 |
hlist_add_head(&dentry->d_u.d_alias, &inode->i_dentry); |
a528aca7f use ->d_seq to ge... |
1718 |
raw_write_seqcount_begin(&dentry->d_seq); |
4bf46a272 VFS: Impose order... |
1719 |
__d_set_inode_and_type(dentry, inode, add_flags); |
a528aca7f use ->d_seq to ge... |
1720 |
raw_write_seqcount_end(&dentry->d_seq); |
affda4841 trim fsnotify hoo... |
1721 |
fsnotify_update_flags(dentry); |
b23fb0a60 fs: scale inode a... |
1722 |
spin_unlock(&dentry->d_lock); |
360da9002 [PATCH vfs-2.6 3/... |
1723 |
} |
1da177e4c Linux-2.6.12-rc2 |
1724 1725 1726 1727 1728 1729 1730 1731 1732 1733 1734 1735 1736 1737 1738 1739 1740 |
/** * d_instantiate - fill in inode information for a dentry * @entry: dentry to complete * @inode: inode to attach to this dentry * * Fill in inode information in the entry. * * This turns negative dentries into productive full members * of society. * * NOTE! This assumes that the inode count has been incremented * (or otherwise set) by the caller to indicate that it is now * in use by the dcache. */ void d_instantiate(struct dentry *entry, struct inode * inode) { |
946e51f2b move d_rcu from o... |
1741 |
BUG_ON(!hlist_unhashed(&entry->d_u.d_alias)); |
de689f5e3 don't bother with... |
1742 |
if (inode) { |
b96809173 security_d_instan... |
1743 |
security_d_instantiate(entry, inode); |
873feea09 fs: dcache per-in... |
1744 |
spin_lock(&inode->i_lock); |
de689f5e3 don't bother with... |
1745 |
__d_instantiate(entry, inode); |
873feea09 fs: dcache per-in... |
1746 |
spin_unlock(&inode->i_lock); |
de689f5e3 don't bother with... |
1747 |
} |
1da177e4c Linux-2.6.12-rc2 |
1748 |
} |
ec4f86059 fs/dcache.c: Codi... |
1749 |
EXPORT_SYMBOL(d_instantiate); |
1da177e4c Linux-2.6.12-rc2 |
1750 1751 |
/** |
b70a80e7a vfs: introduce d_... |
1752 1753 1754 1755 1756 1757 1758 1759 1760 1761 |
* d_instantiate_no_diralias - instantiate a non-aliased dentry * @entry: dentry to complete * @inode: inode to attach to this dentry * * Fill in inode information in the entry. If a directory alias is found, then * return an error (and drop inode). Together with d_materialise_unique() this * guarantees that a directory inode may never have more than one alias. */ int d_instantiate_no_diralias(struct dentry *entry, struct inode *inode) { |
946e51f2b move d_rcu from o... |
1762 |
BUG_ON(!hlist_unhashed(&entry->d_u.d_alias)); |
b70a80e7a vfs: introduce d_... |
1763 |
|
b96809173 security_d_instan... |
1764 |
security_d_instantiate(entry, inode); |
b70a80e7a vfs: introduce d_... |
1765 1766 1767 1768 1769 1770 1771 1772 |
spin_lock(&inode->i_lock); if (S_ISDIR(inode->i_mode) && !hlist_empty(&inode->i_dentry)) { spin_unlock(&inode->i_lock); iput(inode); return -EBUSY; } __d_instantiate(entry, inode); spin_unlock(&inode->i_lock); |
b70a80e7a vfs: introduce d_... |
1773 1774 1775 1776 |
return 0; } EXPORT_SYMBOL(d_instantiate_no_diralias); |
adc0e91ab vfs: new helper -... |
1777 1778 1779 1780 1781 |
struct dentry *d_make_root(struct inode *root_inode) { struct dentry *res = NULL; if (root_inode) { |
798434bda __d_alloc(): trea... |
1782 |
res = __d_alloc(root_inode->i_sb, NULL); |
adc0e91ab vfs: new helper -... |
1783 1784 1785 1786 1787 1788 1789 1790 |
if (res) d_instantiate(res, root_inode); else iput(root_inode); } return res; } EXPORT_SYMBOL(d_make_root); |
d891eedbc fs/dcache: allow ... |
1791 1792 1793 |
static struct dentry * __d_find_any_alias(struct inode *inode) { struct dentry *alias; |
b3d9b7a3c vfs: switch i_den... |
1794 |
if (hlist_empty(&inode->i_dentry)) |
d891eedbc fs/dcache: allow ... |
1795 |
return NULL; |
946e51f2b move d_rcu from o... |
1796 |
alias = hlist_entry(inode->i_dentry.first, struct dentry, d_u.d_alias); |
d891eedbc fs/dcache: allow ... |
1797 1798 1799 |
__dget(alias); return alias; } |
46f72b349 vfs: export symbo... |
1800 1801 1802 1803 1804 1805 1806 1807 |
/** * d_find_any_alias - find any alias for a given inode * @inode: inode to find an alias for * * If any aliases exist for the given inode, take and return a * reference for one of them. If no aliases exist, return %NULL. */ struct dentry *d_find_any_alias(struct inode *inode) |
d891eedbc fs/dcache: allow ... |
1808 1809 1810 1811 1812 1813 1814 1815 |
{ struct dentry *de; spin_lock(&inode->i_lock); de = __d_find_any_alias(inode); spin_unlock(&inode->i_lock); return de; } |
46f72b349 vfs: export symbo... |
1816 |
EXPORT_SYMBOL(d_find_any_alias); |
d891eedbc fs/dcache: allow ... |
1817 |
|
49c7dd287 fs: mark __d_obta... |
1818 |
static struct dentry *__d_obtain_alias(struct inode *inode, int disconnected) |
4ea3ada29 [PATCH] new helpe... |
1819 |
{ |
9308a6128 [PATCH] kill d_al... |
1820 1821 |
struct dentry *tmp; struct dentry *res; |
b18825a7c VFS: Put a small ... |
1822 |
unsigned add_flags; |
4ea3ada29 [PATCH] new helpe... |
1823 1824 |
if (!inode) |
440037287 [PATCH] switch al... |
1825 |
return ERR_PTR(-ESTALE); |
4ea3ada29 [PATCH] new helpe... |
1826 1827 |
if (IS_ERR(inode)) return ERR_CAST(inode); |
d891eedbc fs/dcache: allow ... |
1828 |
res = d_find_any_alias(inode); |
9308a6128 [PATCH] kill d_al... |
1829 1830 |
if (res) goto out_iput; |
798434bda __d_alloc(): trea... |
1831 |
tmp = __d_alloc(inode->i_sb, NULL); |
9308a6128 [PATCH] kill d_al... |
1832 1833 1834 |
if (!tmp) { res = ERR_PTR(-ENOMEM); goto out_iput; |
4ea3ada29 [PATCH] new helpe... |
1835 |
} |
b5c84bf6f fs: dcache remove... |
1836 |
|
b96809173 security_d_instan... |
1837 |
security_d_instantiate(tmp, inode); |
873feea09 fs: dcache per-in... |
1838 |
spin_lock(&inode->i_lock); |
d891eedbc fs/dcache: allow ... |
1839 |
res = __d_find_any_alias(inode); |
9308a6128 [PATCH] kill d_al... |
1840 |
if (res) { |
873feea09 fs: dcache per-in... |
1841 |
spin_unlock(&inode->i_lock); |
9308a6128 [PATCH] kill d_al... |
1842 1843 1844 1845 1846 |
dput(tmp); goto out_iput; } /* attach a disconnected dentry */ |
1a0a397e4 dcache: d_obtain_... |
1847 1848 1849 1850 |
add_flags = d_flags_for_inode(inode); if (disconnected) add_flags |= DCACHE_DISCONNECTED; |
b18825a7c VFS: Put a small ... |
1851 |
|
9308a6128 [PATCH] kill d_al... |
1852 |
spin_lock(&tmp->d_lock); |
4bf46a272 VFS: Impose order... |
1853 |
__d_set_inode_and_type(tmp, inode, add_flags); |
946e51f2b move d_rcu from o... |
1854 |
hlist_add_head(&tmp->d_u.d_alias, &inode->i_dentry); |
1879fd6a2 add hlist_bl_lock... |
1855 |
hlist_bl_lock(&tmp->d_sb->s_anon); |
ceb5bdc2d fs: dcache per-bu... |
1856 |
hlist_bl_add_head(&tmp->d_hash, &tmp->d_sb->s_anon); |
1879fd6a2 add hlist_bl_lock... |
1857 |
hlist_bl_unlock(&tmp->d_sb->s_anon); |
9308a6128 [PATCH] kill d_al... |
1858 |
spin_unlock(&tmp->d_lock); |
873feea09 fs: dcache per-in... |
1859 |
spin_unlock(&inode->i_lock); |
9308a6128 [PATCH] kill d_al... |
1860 |
|
9308a6128 [PATCH] kill d_al... |
1861 1862 1863 1864 1865 |
return tmp; out_iput: iput(inode); return res; |
4ea3ada29 [PATCH] new helpe... |
1866 |
} |
1a0a397e4 dcache: d_obtain_... |
1867 1868 1869 1870 1871 1872 1873 1874 1875 1876 1877 1878 1879 1880 1881 1882 1883 1884 1885 1886 1887 1888 1889 |
/** * d_obtain_alias - find or allocate a DISCONNECTED dentry for a given inode * @inode: inode to allocate the dentry for * * Obtain a dentry for an inode resulting from NFS filehandle conversion or * similar open by handle operations. The returned dentry may be anonymous, * or may have a full name (if the inode was already in the cache). * * When called on a directory inode, we must ensure that the inode only ever * has one dentry. If a dentry is found, that is returned instead of * allocating a new one. * * On successful return, the reference to the inode has been transferred * to the dentry. In case of an error the reference on the inode is released. * To make it easier to use in export operations a %NULL or IS_ERR inode may * be passed in and the error will be propagated to the return value, * with a %NULL @inode replaced by ERR_PTR(-ESTALE). */ struct dentry *d_obtain_alias(struct inode *inode) { return __d_obtain_alias(inode, 1); } |
adc487204 EXPORT_SYMBOL(d_o... |
1890 |
EXPORT_SYMBOL(d_obtain_alias); |
1da177e4c Linux-2.6.12-rc2 |
1891 1892 |
/** |
1a0a397e4 dcache: d_obtain_... |
1893 1894 1895 1896 1897 1898 1899 1900 1901 1902 1903 1904 1905 1906 1907 1908 1909 1910 1911 1912 1913 |
* d_obtain_root - find or allocate a dentry for a given inode * @inode: inode to allocate the dentry for * * Obtain an IS_ROOT dentry for the root of a filesystem. * * We must ensure that directory inodes only ever have one dentry. If a * dentry is found, that is returned instead of allocating a new one. * * On successful return, the reference to the inode has been transferred * to the dentry. In case of an error the reference on the inode is * released. A %NULL or IS_ERR inode may be passed in and will be the * error will be propagate to the return value, with a %NULL @inode * replaced by ERR_PTR(-ESTALE). */ struct dentry *d_obtain_root(struct inode *inode) { return __d_obtain_alias(inode, 0); } EXPORT_SYMBOL(d_obtain_root); /** |
9403540c0 dcache: Add case-... |
1914 1915 1916 1917 1918 1919 1920 1921 1922 1923 1924 1925 1926 1927 1928 |
* d_add_ci - lookup or allocate new dentry with case-exact name * @inode: the inode case-insensitive lookup has found * @dentry: the negative dentry that was passed to the parent's lookup func * @name: the case-exact name to be associated with the returned dentry * * This is to avoid filling the dcache with case-insensitive names to the * same inode, only the actual correct case is stored in the dcache for * case-insensitive filesystems. * * For a case-insensitive lookup match and if the the case-exact dentry * already exists in in the dcache, use it and return it. * * If no entry exists with the exact case name, allocate new dentry with * the exact case, and return the spliced entry. */ |
e45b590b9 [PATCH] change d_... |
1929 |
struct dentry *d_add_ci(struct dentry *dentry, struct inode *inode, |
9403540c0 dcache: Add case-... |
1930 1931 |
struct qstr *name) { |
d9171b934 parallel lookups ... |
1932 |
struct dentry *found, *res; |
9403540c0 dcache: Add case-... |
1933 |
|
b6520c819 cleanup d_add_ci |
1934 1935 1936 1937 |
/* * First check if a dentry matching the name already exists, * if not go ahead and create it now. */ |
9403540c0 dcache: Add case-... |
1938 |
found = d_hash_and_lookup(dentry->d_parent, name); |
d9171b934 parallel lookups ... |
1939 1940 1941 1942 1943 1944 1945 1946 1947 1948 |
if (found) { iput(inode); return found; } if (d_in_lookup(dentry)) { found = d_alloc_parallel(dentry->d_parent, name, dentry->d_wait); if (IS_ERR(found) || !d_in_lookup(found)) { iput(inode); return found; |
9403540c0 dcache: Add case-... |
1949 |
} |
d9171b934 parallel lookups ... |
1950 1951 1952 1953 1954 1955 1956 1957 1958 1959 1960 |
} else { found = d_alloc(dentry->d_parent, name); if (!found) { iput(inode); return ERR_PTR(-ENOMEM); } } res = d_splice_alias(inode, found); if (res) { dput(found); return res; |
9403540c0 dcache: Add case-... |
1961 |
} |
4f522a247 d_hash_and_lookup... |
1962 |
return found; |
9403540c0 dcache: Add case-... |
1963 |
} |
ec4f86059 fs/dcache.c: Codi... |
1964 |
EXPORT_SYMBOL(d_add_ci); |
1da177e4c Linux-2.6.12-rc2 |
1965 |
|
12f8ad4b0 vfs: clean up __d... |
1966 |
|
d4c91a8f7 new helper: d_sam... |
1967 1968 1969 |
static inline bool d_same_name(const struct dentry *dentry, const struct dentry *parent, const struct qstr *name) |
12f8ad4b0 vfs: clean up __d... |
1970 |
{ |
d4c91a8f7 new helper: d_sam... |
1971 1972 1973 1974 |
if (likely(!(parent->d_flags & DCACHE_OP_COMPARE))) { if (dentry->d_name.len != name->len) return false; return dentry_cmp(dentry, name->name, name->len) == 0; |
12f8ad4b0 vfs: clean up __d... |
1975 |
} |
6fa67e707 get rid of 'paren... |
1976 |
return parent->d_op->d_compare(dentry, |
d4c91a8f7 new helper: d_sam... |
1977 1978 |
dentry->d_name.len, dentry->d_name.name, name) == 0; |
12f8ad4b0 vfs: clean up __d... |
1979 |
} |
1da177e4c Linux-2.6.12-rc2 |
1980 |
/** |
31e6b01f4 fs: rcu-walk for ... |
1981 1982 1983 |
* __d_lookup_rcu - search for a dentry (racy, store-free) * @parent: parent dentry * @name: qstr of name we wish to find |
1f1e6e523 fs: fix kernel-do... |
1984 |
* @seqp: returns d_seq value at the point where the dentry was found |
31e6b01f4 fs: rcu-walk for ... |
1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 |
* Returns: dentry, or NULL * * __d_lookup_rcu is the dcache lookup function for rcu-walk name * resolution (store-free path walking) design described in * Documentation/filesystems/path-lookup.txt. * * This is not to be used outside core vfs. * * __d_lookup_rcu must only be used in rcu-walk mode, ie. with vfsmount lock * held, and rcu_read_lock held. The returned dentry must not be stored into * without taking d_lock and checking d_seq sequence count against @seq * returned here. * |
15570086b vfs: reimplement ... |
1998 |
* A refcount may be taken on the found dentry with the d_rcu_to_refcount |
31e6b01f4 fs: rcu-walk for ... |
1999 2000 2001 2002 2003 2004 |
* function. * * Alternatively, __d_lookup_rcu may be called again to look up the child of * the returned dentry, so long as its parent's seqlock is checked after the * child is looked up. Thus, an interlocking stepping of sequence lock checks * is formed, giving integrity down the path walk. |
12f8ad4b0 vfs: clean up __d... |
2005 2006 2007 |
* * NOTE! The caller *has* to check the resulting dentry against the sequence * number we've returned before using any of the resulting dentry state! |
31e6b01f4 fs: rcu-walk for ... |
2008 |
*/ |
8966be903 vfs: trivial __d_... |
2009 2010 |
struct dentry *__d_lookup_rcu(const struct dentry *parent, const struct qstr *name, |
da53be12b Don't pass inode ... |
2011 |
unsigned *seqp) |
31e6b01f4 fs: rcu-walk for ... |
2012 |
{ |
26fe57502 vfs: make it poss... |
2013 |
u64 hashlen = name->hash_len; |
31e6b01f4 fs: rcu-walk for ... |
2014 |
const unsigned char *str = name->name; |
8387ff257 vfs: make the str... |
2015 |
struct hlist_bl_head *b = d_hash(hashlen_hash(hashlen)); |
ceb5bdc2d fs: dcache per-bu... |
2016 |
struct hlist_bl_node *node; |
31e6b01f4 fs: rcu-walk for ... |
2017 2018 2019 2020 2021 2022 2023 2024 2025 2026 2027 2028 2029 2030 2031 2032 2033 2034 2035 2036 |
struct dentry *dentry; /* * Note: There is significant duplication with __d_lookup_rcu which is * required to prevent single threaded performance regressions * especially on architectures where smp_rmb (in seqcounts) are costly. * Keep the two functions in sync. */ /* * The hash list is protected using RCU. * * Carefully use d_seq when comparing a candidate dentry, to avoid * races with d_move(). * * It is possible that concurrent renames can mess up our list * walk here and result in missing our dentry, resulting in the * false-negative result. d_lookup() protects against concurrent * renames using rename_lock seqlock. * |
b0a4bb830 fs: update commen... |
2037 |
* See Documentation/filesystems/path-lookup.txt for more details. |
31e6b01f4 fs: rcu-walk for ... |
2038 |
*/ |
b07ad9967 vfs: get rid of '... |
2039 |
hlist_bl_for_each_entry_rcu(dentry, node, b, d_hash) { |
8966be903 vfs: trivial __d_... |
2040 |
unsigned seq; |
31e6b01f4 fs: rcu-walk for ... |
2041 |
|
31e6b01f4 fs: rcu-walk for ... |
2042 |
seqretry: |
12f8ad4b0 vfs: clean up __d... |
2043 2044 |
/* * The dentry sequence count protects us from concurrent |
da53be12b Don't pass inode ... |
2045 |
* renames, and thus protects parent and name fields. |
12f8ad4b0 vfs: clean up __d... |
2046 2047 |
* * The caller must perform a seqcount check in order |
da53be12b Don't pass inode ... |
2048 |
* to do anything useful with the returned dentry. |
12f8ad4b0 vfs: clean up __d... |
2049 2050 2051 2052 2053 2054 2055 |
* * NOTE! We do a "raw" seqcount_begin here. That means that * we don't wait for the sequence count to stabilize if it * is in the middle of a sequence change. If we do the slow * dentry compare, we will do seqretries until it is stable, * and if we end up with a successful lookup, we actually * want to exit RCU lookup anyway. |
d4c91a8f7 new helper: d_sam... |
2056 2057 2058 |
* * Note that raw_seqcount_begin still *does* smp_rmb(), so * we are still guaranteed NUL-termination of ->d_name.name. |
12f8ad4b0 vfs: clean up __d... |
2059 2060 |
*/ seq = raw_seqcount_begin(&dentry->d_seq); |
31e6b01f4 fs: rcu-walk for ... |
2061 2062 |
if (dentry->d_parent != parent) continue; |
2e321806b Revert "vfs: remo... |
2063 2064 |
if (d_unhashed(dentry)) continue; |
12f8ad4b0 vfs: clean up __d... |
2065 |
|
830c0f0ed vfs: renumber DCA... |
2066 |
if (unlikely(parent->d_flags & DCACHE_OP_COMPARE)) { |
d4c91a8f7 new helper: d_sam... |
2067 2068 |
int tlen; const char *tname; |
26fe57502 vfs: make it poss... |
2069 2070 |
if (dentry->d_name.hash != hashlen_hash(hashlen)) continue; |
d4c91a8f7 new helper: d_sam... |
2071 2072 2073 2074 2075 |
tlen = dentry->d_name.len; tname = dentry->d_name.name; /* we want a consistent (name,len) pair */ if (read_seqcount_retry(&dentry->d_seq, seq)) { cpu_relax(); |
12f8ad4b0 vfs: clean up __d... |
2076 2077 |
goto seqretry; } |
6fa67e707 get rid of 'paren... |
2078 |
if (parent->d_op->d_compare(dentry, |
d4c91a8f7 new helper: d_sam... |
2079 2080 2081 2082 2083 2084 2085 |
tlen, tname, name) != 0) continue; } else { if (dentry->d_name.hash_len != hashlen) continue; if (dentry_cmp(dentry, str, hashlen_len(hashlen)) != 0) continue; |
31e6b01f4 fs: rcu-walk for ... |
2086 |
} |
da53be12b Don't pass inode ... |
2087 |
*seqp = seq; |
d4c91a8f7 new helper: d_sam... |
2088 |
return dentry; |
31e6b01f4 fs: rcu-walk for ... |
2089 2090 2091 2092 2093 |
} return NULL; } /** |
1da177e4c Linux-2.6.12-rc2 |
2094 2095 2096 |
* d_lookup - search for a dentry * @parent: parent dentry * @name: qstr of name we wish to find |
b04f784e5 fs: remove extra ... |
2097 |
* Returns: dentry, or NULL |
1da177e4c Linux-2.6.12-rc2 |
2098 |
* |
b04f784e5 fs: remove extra ... |
2099 2100 2101 2102 |
* d_lookup searches the children of the parent dentry for the name in * question. If the dentry is found its reference count is incremented and the * dentry is returned. The caller must use dput to free the entry when it has * finished using it. %NULL is returned if the dentry does not exist. |
1da177e4c Linux-2.6.12-rc2 |
2103 |
*/ |
da2d8455e constify d_lookup... |
2104 |
struct dentry *d_lookup(const struct dentry *parent, const struct qstr *name) |
1da177e4c Linux-2.6.12-rc2 |
2105 |
{ |
31e6b01f4 fs: rcu-walk for ... |
2106 |
struct dentry *dentry; |
949854d02 fs: Use rename lo... |
2107 |
unsigned seq; |
1da177e4c Linux-2.6.12-rc2 |
2108 |
|
b8314f930 dcache: Fix no sp... |
2109 2110 2111 2112 |
do { seq = read_seqbegin(&rename_lock); dentry = __d_lookup(parent, name); if (dentry) |
1da177e4c Linux-2.6.12-rc2 |
2113 2114 2115 2116 |
break; } while (read_seqretry(&rename_lock, seq)); return dentry; } |
ec4f86059 fs/dcache.c: Codi... |
2117 |
EXPORT_SYMBOL(d_lookup); |
1da177e4c Linux-2.6.12-rc2 |
2118 |
|
31e6b01f4 fs: rcu-walk for ... |
2119 |
/** |
b04f784e5 fs: remove extra ... |
2120 2121 2122 2123 2124 2125 2126 2127 2128 2129 2130 2131 2132 2133 |
* __d_lookup - search for a dentry (racy) * @parent: parent dentry * @name: qstr of name we wish to find * Returns: dentry, or NULL * * __d_lookup is like d_lookup, however it may (rarely) return a * false-negative result due to unrelated rename activity. * * __d_lookup is slightly faster by avoiding rename_lock read seqlock, * however it must be used carefully, eg. with a following d_lookup in * the case of failure. * * __d_lookup callers must be commented. */ |
a713ca2ab constify __d_look... |
2134 |
struct dentry *__d_lookup(const struct dentry *parent, const struct qstr *name) |
1da177e4c Linux-2.6.12-rc2 |
2135 |
{ |
1da177e4c Linux-2.6.12-rc2 |
2136 |
unsigned int hash = name->hash; |
8387ff257 vfs: make the str... |
2137 |
struct hlist_bl_head *b = d_hash(hash); |
ceb5bdc2d fs: dcache per-bu... |
2138 |
struct hlist_bl_node *node; |
31e6b01f4 fs: rcu-walk for ... |
2139 |
struct dentry *found = NULL; |
665a7583f [PATCH] Remove hl... |
2140 |
struct dentry *dentry; |
1da177e4c Linux-2.6.12-rc2 |
2141 |
|
b04f784e5 fs: remove extra ... |
2142 |
/* |
31e6b01f4 fs: rcu-walk for ... |
2143 2144 2145 2146 2147 2148 2149 |
* Note: There is significant duplication with __d_lookup_rcu which is * required to prevent single threaded performance regressions * especially on architectures where smp_rmb (in seqcounts) are costly. * Keep the two functions in sync. */ /* |
b04f784e5 fs: remove extra ... |
2150 2151 2152 2153 2154 2155 2156 2157 2158 2159 |
* The hash list is protected using RCU. * * Take d_lock when comparing a candidate dentry, to avoid races * with d_move(). * * It is possible that concurrent renames can mess up our list * walk here and result in missing our dentry, resulting in the * false-negative result. d_lookup() protects against concurrent * renames using rename_lock seqlock. * |
b0a4bb830 fs: update commen... |
2160 |
* See Documentation/filesystems/path-lookup.txt for more details. |
b04f784e5 fs: remove extra ... |
2161 |
*/ |
1da177e4c Linux-2.6.12-rc2 |
2162 2163 |
rcu_read_lock(); |
b07ad9967 vfs: get rid of '... |
2164 |
hlist_bl_for_each_entry_rcu(dentry, node, b, d_hash) { |
1da177e4c Linux-2.6.12-rc2 |
2165 |
|
1da177e4c Linux-2.6.12-rc2 |
2166 2167 |
if (dentry->d_name.hash != hash) continue; |
1da177e4c Linux-2.6.12-rc2 |
2168 2169 |
spin_lock(&dentry->d_lock); |
1da177e4c Linux-2.6.12-rc2 |
2170 2171 |
if (dentry->d_parent != parent) goto next; |
d0185c088 Fix NULL pointer ... |
2172 2173 |
if (d_unhashed(dentry)) goto next; |
d4c91a8f7 new helper: d_sam... |
2174 2175 |
if (!d_same_name(dentry, parent, name)) goto next; |
1da177e4c Linux-2.6.12-rc2 |
2176 |
|
98474236f vfs: make the den... |
2177 |
dentry->d_lockref.count++; |
d0185c088 Fix NULL pointer ... |
2178 |
found = dentry; |
1da177e4c Linux-2.6.12-rc2 |
2179 2180 2181 2182 2183 2184 2185 2186 2187 2188 2189 |
spin_unlock(&dentry->d_lock); break; next: spin_unlock(&dentry->d_lock); } rcu_read_unlock(); return found; } /** |
3e7e241f8 [PATCH] dcache: A... |
2190 2191 2192 2193 |
* d_hash_and_lookup - hash the qstr then search for a dentry * @dir: Directory to search in * @name: qstr of name we wish to find * |
4f522a247 d_hash_and_lookup... |
2194 |
* On lookup failure NULL is returned; on bad name - ERR_PTR(-error) |
3e7e241f8 [PATCH] dcache: A... |
2195 2196 2197 |
*/ struct dentry *d_hash_and_lookup(struct dentry *dir, struct qstr *name) { |
3e7e241f8 [PATCH] dcache: A... |
2198 2199 2200 2201 2202 |
/* * Check for a fs-specific hash function. Note that we must * calculate the standard hash first, as the d_op->d_hash() * routine may choose to leave the hash value unchanged. */ |
8387ff257 vfs: make the str... |
2203 |
name->hash = full_name_hash(dir, name->name, name->len); |
fb045adb9 fs: dcache reduce... |
2204 |
if (dir->d_flags & DCACHE_OP_HASH) { |
da53be12b Don't pass inode ... |
2205 |
int err = dir->d_op->d_hash(dir, name); |
4f522a247 d_hash_and_lookup... |
2206 2207 |
if (unlikely(err < 0)) return ERR_PTR(err); |
3e7e241f8 [PATCH] dcache: A... |
2208 |
} |
4f522a247 d_hash_and_lookup... |
2209 |
return d_lookup(dir, name); |
3e7e241f8 [PATCH] dcache: A... |
2210 |
} |
4f522a247 d_hash_and_lookup... |
2211 |
EXPORT_SYMBOL(d_hash_and_lookup); |
3e7e241f8 [PATCH] dcache: A... |
2212 |
|
1da177e4c Linux-2.6.12-rc2 |
2213 2214 2215 2216 2217 2218 2219 2220 2221 2222 2223 2224 2225 2226 2227 2228 2229 2230 2231 2232 2233 2234 2235 |
/* * When a file is deleted, we have two options: * - turn this dentry into a negative dentry * - unhash this dentry and free it. * * Usually, we want to just turn this into * a negative dentry, but if anybody else is * currently using the dentry or the inode * we can't do that and we fall back on removing * it from the hash queues and waiting for * it to be deleted later when it has no users */ /** * d_delete - delete a dentry * @dentry: The dentry to delete * * Turn the dentry into a negative dentry if possible, otherwise * remove it from the hash queues so it can be deleted later */ void d_delete(struct dentry * dentry) { |
873feea09 fs: dcache per-in... |
2236 |
struct inode *inode; |
7a91bf7f5 [PATCH] fsnotify_... |
2237 |
int isdir = 0; |
1da177e4c Linux-2.6.12-rc2 |
2238 2239 2240 |
/* * Are we the only user? */ |
357f8e658 fs: dcache reduce... |
2241 |
again: |
1da177e4c Linux-2.6.12-rc2 |
2242 |
spin_lock(&dentry->d_lock); |
873feea09 fs: dcache per-in... |
2243 2244 |
inode = dentry->d_inode; isdir = S_ISDIR(inode->i_mode); |
98474236f vfs: make the den... |
2245 |
if (dentry->d_lockref.count == 1) { |
1fe0c0230 vfs: delete surpl... |
2246 |
if (!spin_trylock(&inode->i_lock)) { |
357f8e658 fs: dcache reduce... |
2247 2248 2249 2250 |
spin_unlock(&dentry->d_lock); cpu_relax(); goto again; } |
13e3c5e5b clean DCACHE_CANT... |
2251 |
dentry->d_flags &= ~DCACHE_CANT_MOUNT; |
31e6b01f4 fs: rcu-walk for ... |
2252 |
dentry_unlink_inode(dentry); |
7a91bf7f5 [PATCH] fsnotify_... |
2253 |
fsnotify_nameremove(dentry, isdir); |
1da177e4c Linux-2.6.12-rc2 |
2254 2255 2256 2257 2258 2259 2260 |
return; } if (!d_unhashed(dentry)) __d_drop(dentry); spin_unlock(&dentry->d_lock); |
7a91bf7f5 [PATCH] fsnotify_... |
2261 2262 |
fsnotify_nameremove(dentry, isdir); |
1da177e4c Linux-2.6.12-rc2 |
2263 |
} |
ec4f86059 fs/dcache.c: Codi... |
2264 |
EXPORT_SYMBOL(d_delete); |
1da177e4c Linux-2.6.12-rc2 |
2265 |
|
15d3c589f fold _d_rehash() ... |
2266 |
static void __d_rehash(struct dentry *entry) |
1da177e4c Linux-2.6.12-rc2 |
2267 |
{ |
15d3c589f fold _d_rehash() ... |
2268 |
struct hlist_bl_head *b = d_hash(entry->d_name.hash); |
ceb5bdc2d fs: dcache per-bu... |
2269 |
BUG_ON(!d_unhashed(entry)); |
1879fd6a2 add hlist_bl_lock... |
2270 |
hlist_bl_lock(b); |
b07ad9967 vfs: get rid of '... |
2271 |
hlist_bl_add_head_rcu(&entry->d_hash, b); |
1879fd6a2 add hlist_bl_lock... |
2272 |
hlist_bl_unlock(b); |
1da177e4c Linux-2.6.12-rc2 |
2273 2274 2275 2276 2277 2278 2279 2280 2281 2282 2283 |
} /** * d_rehash - add an entry back to the hash * @entry: dentry to add to the hash * * Adds a dentry to the hash according to its name. */ void d_rehash(struct dentry * entry) { |
1da177e4c Linux-2.6.12-rc2 |
2284 |
spin_lock(&entry->d_lock); |
15d3c589f fold _d_rehash() ... |
2285 |
__d_rehash(entry); |
1da177e4c Linux-2.6.12-rc2 |
2286 |
spin_unlock(&entry->d_lock); |
1da177e4c Linux-2.6.12-rc2 |
2287 |
} |
ec4f86059 fs/dcache.c: Codi... |
2288 |
EXPORT_SYMBOL(d_rehash); |
1da177e4c Linux-2.6.12-rc2 |
2289 |
|
84e710da2 parallel lookups ... |
2290 2291 2292 2293 2294 2295 2296 2297 2298 2299 2300 2301 2302 2303 2304 |
static inline unsigned start_dir_add(struct inode *dir) { for (;;) { unsigned n = dir->i_dir_seq; if (!(n & 1) && cmpxchg(&dir->i_dir_seq, n, n + 1) == n) return n; cpu_relax(); } } static inline void end_dir_add(struct inode *dir, unsigned n) { smp_store_release(&dir->i_dir_seq, n + 2); } |
d9171b934 parallel lookups ... |
2305 2306 2307 2308 2309 2310 2311 2312 2313 2314 2315 2316 2317 |
static void d_wait_lookup(struct dentry *dentry) { if (d_in_lookup(dentry)) { DECLARE_WAITQUEUE(wait, current); add_wait_queue(dentry->d_wait, &wait); do { set_current_state(TASK_UNINTERRUPTIBLE); spin_unlock(&dentry->d_lock); schedule(); spin_lock(&dentry->d_lock); } while (d_in_lookup(dentry)); } } |
94bdd655c parallel lookups ... |
2318 |
struct dentry *d_alloc_parallel(struct dentry *parent, |
d9171b934 parallel lookups ... |
2319 2320 |
const struct qstr *name, wait_queue_head_t *wq) |
94bdd655c parallel lookups ... |
2321 |
{ |
94bdd655c parallel lookups ... |
2322 |
unsigned int hash = name->hash; |
94bdd655c parallel lookups ... |
2323 2324 2325 2326 2327 2328 2329 2330 2331 2332 2333 2334 2335 2336 2337 2338 2339 2340 2341 2342 2343 2344 2345 2346 2347 2348 2349 2350 2351 2352 2353 2354 2355 2356 2357 2358 2359 2360 |
struct hlist_bl_head *b = in_lookup_hash(parent, hash); struct hlist_bl_node *node; struct dentry *new = d_alloc(parent, name); struct dentry *dentry; unsigned seq, r_seq, d_seq; if (unlikely(!new)) return ERR_PTR(-ENOMEM); retry: rcu_read_lock(); seq = smp_load_acquire(&parent->d_inode->i_dir_seq) & ~1; r_seq = read_seqbegin(&rename_lock); dentry = __d_lookup_rcu(parent, name, &d_seq); if (unlikely(dentry)) { if (!lockref_get_not_dead(&dentry->d_lockref)) { rcu_read_unlock(); goto retry; } if (read_seqcount_retry(&dentry->d_seq, d_seq)) { rcu_read_unlock(); dput(dentry); goto retry; } rcu_read_unlock(); dput(new); return dentry; } if (unlikely(read_seqretry(&rename_lock, r_seq))) { rcu_read_unlock(); goto retry; } hlist_bl_lock(b); if (unlikely(parent->d_inode->i_dir_seq != seq)) { hlist_bl_unlock(b); rcu_read_unlock(); goto retry; } |
94bdd655c parallel lookups ... |
2361 2362 2363 2364 2365 2366 2367 2368 2369 2370 2371 2372 |
/* * No changes for the parent since the beginning of d_lookup(). * Since all removals from the chain happen with hlist_bl_lock(), * any potential in-lookup matches are going to stay here until * we unlock the chain. All fields are stable in everything * we encounter. */ hlist_bl_for_each_entry(dentry, node, b, d_u.d_in_lookup_hash) { if (dentry->d_name.hash != hash) continue; if (dentry->d_parent != parent) continue; |
d4c91a8f7 new helper: d_sam... |
2373 2374 |
if (!d_same_name(dentry, parent, name)) continue; |
94bdd655c parallel lookups ... |
2375 |
hlist_bl_unlock(b); |
e7d6ef979 fix idiotic brain... |
2376 2377 2378 2379 2380 2381 2382 2383 2384 2385 2386 |
/* now we can try to grab a reference */ if (!lockref_get_not_dead(&dentry->d_lockref)) { rcu_read_unlock(); goto retry; } rcu_read_unlock(); /* * somebody is likely to be still doing lookup for it; * wait for them to finish */ |
d9171b934 parallel lookups ... |
2387 2388 2389 2390 2391 2392 2393 2394 2395 2396 2397 2398 2399 2400 |
spin_lock(&dentry->d_lock); d_wait_lookup(dentry); /* * it's not in-lookup anymore; in principle we should repeat * everything from dcache lookup, but it's likely to be what * d_lookup() would've found anyway. If it is, just return it; * otherwise we really have to repeat the whole thing. */ if (unlikely(dentry->d_name.hash != hash)) goto mismatch; if (unlikely(dentry->d_parent != parent)) goto mismatch; if (unlikely(d_unhashed(dentry))) goto mismatch; |
d4c91a8f7 new helper: d_sam... |
2401 2402 |
if (unlikely(!d_same_name(dentry, parent, name))) goto mismatch; |
d9171b934 parallel lookups ... |
2403 2404 |
/* OK, it *is* a hashed match; return it */ spin_unlock(&dentry->d_lock); |
94bdd655c parallel lookups ... |
2405 2406 2407 |
dput(new); return dentry; } |
e7d6ef979 fix idiotic brain... |
2408 |
rcu_read_unlock(); |
94bdd655c parallel lookups ... |
2409 2410 |
/* we can't take ->d_lock here; it's OK, though. */ new->d_flags |= DCACHE_PAR_LOOKUP; |
d9171b934 parallel lookups ... |
2411 |
new->d_wait = wq; |
94bdd655c parallel lookups ... |
2412 2413 2414 |
hlist_bl_add_head_rcu(&new->d_u.d_in_lookup_hash, b); hlist_bl_unlock(b); return new; |
d9171b934 parallel lookups ... |
2415 2416 2417 2418 |
mismatch: spin_unlock(&dentry->d_lock); dput(dentry); goto retry; |
94bdd655c parallel lookups ... |
2419 2420 |
} EXPORT_SYMBOL(d_alloc_parallel); |
85c7f8104 beginning of tran... |
2421 2422 |
void __d_lookup_done(struct dentry *dentry) { |
94bdd655c parallel lookups ... |
2423 2424 2425 |
struct hlist_bl_head *b = in_lookup_hash(dentry->d_parent, dentry->d_name.hash); hlist_bl_lock(b); |
85c7f8104 beginning of tran... |
2426 |
dentry->d_flags &= ~DCACHE_PAR_LOOKUP; |
94bdd655c parallel lookups ... |
2427 |
__hlist_bl_del(&dentry->d_u.d_in_lookup_hash); |
d9171b934 parallel lookups ... |
2428 2429 |
wake_up_all(dentry->d_wait); dentry->d_wait = NULL; |
94bdd655c parallel lookups ... |
2430 2431 |
hlist_bl_unlock(b); INIT_HLIST_NODE(&dentry->d_u.d_alias); |
d9171b934 parallel lookups ... |
2432 |
INIT_LIST_HEAD(&dentry->d_lru); |
85c7f8104 beginning of tran... |
2433 2434 |
} EXPORT_SYMBOL(__d_lookup_done); |
ed782b5a7 dcache.c: new hel... |
2435 2436 2437 2438 2439 |
/* inode->i_lock held if inode is non-NULL */ static inline void __d_add(struct dentry *dentry, struct inode *inode) { |
84e710da2 parallel lookups ... |
2440 2441 |
struct inode *dir = NULL; unsigned n; |
0568d705b __d_add(): don't ... |
2442 |
spin_lock(&dentry->d_lock); |
84e710da2 parallel lookups ... |
2443 2444 2445 |
if (unlikely(d_in_lookup(dentry))) { dir = dentry->d_parent->d_inode; n = start_dir_add(dir); |
85c7f8104 beginning of tran... |
2446 |
__d_lookup_done(dentry); |
84e710da2 parallel lookups ... |
2447 |
} |
ed782b5a7 dcache.c: new hel... |
2448 |
if (inode) { |
0568d705b __d_add(): don't ... |
2449 2450 2451 2452 2453 |
unsigned add_flags = d_flags_for_inode(inode); hlist_add_head(&dentry->d_u.d_alias, &inode->i_dentry); raw_write_seqcount_begin(&dentry->d_seq); __d_set_inode_and_type(dentry, inode, add_flags); raw_write_seqcount_end(&dentry->d_seq); |
affda4841 trim fsnotify hoo... |
2454 |
fsnotify_update_flags(dentry); |
ed782b5a7 dcache.c: new hel... |
2455 |
} |
15d3c589f fold _d_rehash() ... |
2456 |
__d_rehash(dentry); |
84e710da2 parallel lookups ... |
2457 2458 |
if (dir) end_dir_add(dir, n); |
0568d705b __d_add(): don't ... |
2459 2460 2461 |
spin_unlock(&dentry->d_lock); if (inode) spin_unlock(&inode->i_lock); |
ed782b5a7 dcache.c: new hel... |
2462 |
} |
fb2d5b86a fs: name case upd... |
2463 |
/** |
34d0d19dc uninline d_add() |
2464 2465 2466 2467 2468 2469 2470 2471 2472 2473 |
* d_add - add dentry to hash queues * @entry: dentry to add * @inode: The inode to attach to this dentry * * This adds the entry to the hash queues and initializes @inode. * The entry was actually filled in earlier during d_alloc(). */ void d_add(struct dentry *entry, struct inode *inode) { |
b96809173 security_d_instan... |
2474 2475 |
if (inode) { security_d_instantiate(entry, inode); |
ed782b5a7 dcache.c: new hel... |
2476 |
spin_lock(&inode->i_lock); |
b96809173 security_d_instan... |
2477 |
} |
ed782b5a7 dcache.c: new hel... |
2478 |
__d_add(entry, inode); |
34d0d19dc uninline d_add() |
2479 2480 2481 2482 |
} EXPORT_SYMBOL(d_add); /** |
668d0cd56 replace d_add_uni... |
2483 2484 2485 2486 2487 2488 2489 2490 2491 2492 2493 2494 2495 |
* d_exact_alias - find and hash an exact unhashed alias * @entry: dentry to add * @inode: The inode to go with this dentry * * If an unhashed dentry with the same name/parent and desired * inode already exists, hash and return it. Otherwise, return * NULL. * * Parent directory should be locked. */ struct dentry *d_exact_alias(struct dentry *entry, struct inode *inode) { struct dentry *alias; |
668d0cd56 replace d_add_uni... |
2496 2497 2498 2499 2500 2501 2502 2503 2504 2505 2506 2507 2508 |
unsigned int hash = entry->d_name.hash; spin_lock(&inode->i_lock); hlist_for_each_entry(alias, &inode->i_dentry, d_u.d_alias) { /* * Don't need alias->d_lock here, because aliases with * d_parent == entry->d_parent are not subject to name or * parent changes, because the parent inode i_mutex is held. */ if (alias->d_name.hash != hash) continue; if (alias->d_parent != entry->d_parent) continue; |
d4c91a8f7 new helper: d_sam... |
2509 |
if (!d_same_name(alias, entry->d_parent, &entry->d_name)) |
668d0cd56 replace d_add_uni... |
2510 2511 2512 2513 2514 2515 2516 |
continue; spin_lock(&alias->d_lock); if (!d_unhashed(alias)) { spin_unlock(&alias->d_lock); alias = NULL; } else { __dget_dlock(alias); |
15d3c589f fold _d_rehash() ... |
2517 |
__d_rehash(alias); |
668d0cd56 replace d_add_uni... |
2518 2519 2520 2521 2522 2523 2524 2525 2526 2527 2528 |
spin_unlock(&alias->d_lock); } spin_unlock(&inode->i_lock); return alias; } spin_unlock(&inode->i_lock); return NULL; } EXPORT_SYMBOL(d_exact_alias); /** |
fb2d5b86a fs: name case upd... |
2529 2530 2531 2532 2533 2534 2535 2536 2537 2538 2539 2540 2541 |
* dentry_update_name_case - update case insensitive dentry with a new name * @dentry: dentry to be updated * @name: new name * * Update a case insensitive dentry with new case of name. * * dentry must have been returned by d_lookup with name @name. Old and new * name lengths must match (ie. no d_compare which allows mismatched name * lengths). * * Parent inode i_mutex must be held over d_lookup and into this call (to * keep renames and concurrent inserts, and readdir(2) away). */ |
9aba36dea qstr constify ins... |
2542 |
void dentry_update_name_case(struct dentry *dentry, const struct qstr *name) |
fb2d5b86a fs: name case upd... |
2543 |
{ |
5955102c9 wrappers for ->i_... |
2544 |
BUG_ON(!inode_is_locked(dentry->d_parent->d_inode)); |
fb2d5b86a fs: name case upd... |
2545 |
BUG_ON(dentry->d_name.len != name->len); /* d_lookup gives this */ |
fb2d5b86a fs: name case upd... |
2546 |
spin_lock(&dentry->d_lock); |
31e6b01f4 fs: rcu-walk for ... |
2547 |
write_seqcount_begin(&dentry->d_seq); |
fb2d5b86a fs: name case upd... |
2548 |
memcpy((unsigned char *)dentry->d_name.name, name->name, name->len); |
31e6b01f4 fs: rcu-walk for ... |
2549 |
write_seqcount_end(&dentry->d_seq); |
fb2d5b86a fs: name case upd... |
2550 |
spin_unlock(&dentry->d_lock); |
fb2d5b86a fs: name case upd... |
2551 2552 |
} EXPORT_SYMBOL(dentry_update_name_case); |
8d85b4845 Allow sharing ext... |
2553 |
static void swap_names(struct dentry *dentry, struct dentry *target) |
1da177e4c Linux-2.6.12-rc2 |
2554 |
{ |
8d85b4845 Allow sharing ext... |
2555 2556 |
if (unlikely(dname_external(target))) { if (unlikely(dname_external(dentry))) { |
1da177e4c Linux-2.6.12-rc2 |
2557 2558 2559 |
/* * Both external: swap the pointers */ |
9a8d5bb4a generic swap(): d... |
2560 |
swap(target->d_name.name, dentry->d_name.name); |
1da177e4c Linux-2.6.12-rc2 |
2561 2562 2563 2564 2565 |
} else { /* * dentry:internal, target:external. Steal target's * storage and make target internal. */ |
321bcf921 dcache: don't exp... |
2566 2567 |
memcpy(target->d_iname, dentry->d_name.name, dentry->d_name.len + 1); |
1da177e4c Linux-2.6.12-rc2 |
2568 2569 2570 2571 |
dentry->d_name.name = target->d_name.name; target->d_name.name = target->d_iname; } } else { |
8d85b4845 Allow sharing ext... |
2572 |
if (unlikely(dname_external(dentry))) { |
1da177e4c Linux-2.6.12-rc2 |
2573 2574 2575 2576 2577 2578 2579 2580 2581 2582 |
/* * dentry:external, target:internal. Give dentry's * storage to target and make dentry internal */ memcpy(dentry->d_iname, target->d_name.name, target->d_name.len + 1); target->d_name.name = dentry->d_name.name; dentry->d_name.name = dentry->d_iname; } else { /* |
da1ce0670 vfs: add cross-re... |
2583 |
* Both are internal. |
1da177e4c Linux-2.6.12-rc2 |
2584 |
*/ |
da1ce0670 vfs: add cross-re... |
2585 2586 |
unsigned int i; BUILD_BUG_ON(!IS_ALIGNED(DNAME_INLINE_LEN, sizeof(long))); |
08d4f7722 dcache: fix kmemc... |
2587 2588 |
kmemcheck_mark_initialized(dentry->d_iname, DNAME_INLINE_LEN); kmemcheck_mark_initialized(target->d_iname, DNAME_INLINE_LEN); |
da1ce0670 vfs: add cross-re... |
2589 2590 2591 2592 |
for (i = 0; i < DNAME_INLINE_LEN / sizeof(long); i++) { swap(((long *) &dentry->d_iname)[i], ((long *) &target->d_iname)[i]); } |
1da177e4c Linux-2.6.12-rc2 |
2593 2594 |
} } |
a28ddb87c fold swapping ->d... |
2595 |
swap(dentry->d_name.hash_len, target->d_name.hash_len); |
1da177e4c Linux-2.6.12-rc2 |
2596 |
} |
8d85b4845 Allow sharing ext... |
2597 2598 2599 2600 2601 2602 2603 2604 2605 2606 2607 2608 2609 2610 2611 2612 2613 |
static void copy_name(struct dentry *dentry, struct dentry *target) { struct external_name *old_name = NULL; if (unlikely(dname_external(dentry))) old_name = external_name(dentry); if (unlikely(dname_external(target))) { atomic_inc(&external_name(target)->u.count); dentry->d_name = target->d_name; } else { memcpy(dentry->d_iname, target->d_name.name, target->d_name.len + 1); dentry->d_name.name = dentry->d_iname; dentry->d_name.hash_len = target->d_name.hash_len; } if (old_name && likely(atomic_dec_and_test(&old_name->u.count))) kfree_rcu(old_name, u.head); } |
2fd6b7f50 fs: dcache scale ... |
2614 2615 2616 2617 2618 2619 2620 2621 2622 2623 2624 2625 2626 2627 2628 2629 2630 2631 2632 2633 2634 2635 2636 2637 2638 2639 |
static void dentry_lock_for_move(struct dentry *dentry, struct dentry *target) { /* * XXXX: do we really need to take target->d_lock? */ if (IS_ROOT(dentry) || dentry->d_parent == target->d_parent) spin_lock(&target->d_parent->d_lock); else { if (d_ancestor(dentry->d_parent, target->d_parent)) { spin_lock(&dentry->d_parent->d_lock); spin_lock_nested(&target->d_parent->d_lock, DENTRY_D_LOCK_NESTED); } else { spin_lock(&target->d_parent->d_lock); spin_lock_nested(&dentry->d_parent->d_lock, DENTRY_D_LOCK_NESTED); } } if (target < dentry) { spin_lock_nested(&target->d_lock, 2); spin_lock_nested(&dentry->d_lock, 3); } else { spin_lock_nested(&dentry->d_lock, 2); spin_lock_nested(&target->d_lock, 3); } } |
986c01942 fold unlocking th... |
2640 |
static void dentry_unlock_for_move(struct dentry *dentry, struct dentry *target) |
2fd6b7f50 fs: dcache scale ... |
2641 2642 2643 2644 2645 |
{ if (target->d_parent != dentry->d_parent) spin_unlock(&dentry->d_parent->d_lock); if (target->d_parent != target) spin_unlock(&target->d_parent->d_lock); |
986c01942 fold unlocking th... |
2646 2647 |
spin_unlock(&target->d_lock); spin_unlock(&dentry->d_lock); |
2fd6b7f50 fs: dcache scale ... |
2648 |
} |
1da177e4c Linux-2.6.12-rc2 |
2649 |
/* |
2fd6b7f50 fs: dcache scale ... |
2650 2651 2652 |
* When switching names, the actual string doesn't strictly have to * be preserved in the target - because we're dropping the target * anyway. As such, we can just do a simple memcpy() to copy over |
d2fa4a847 vfs: Don't exchan... |
2653 2654 2655 2656 2657 2658 2659 2660 2661 |
* the new name before we switch, unless we are going to rehash * it. Note that if we *do* unhash the target, we are not allowed * to rehash it without giving it a new name/hash key - whether * we swap or overwrite the names here, resulting name won't match * the reality in filesystem; it's only there for d_path() purposes. * Note that all of this is happening under rename_lock, so the * any hash lookup seeing it in the middle of manipulations will * be discarded anyway. So we do not care what happens to the hash * key in that case. |
1da177e4c Linux-2.6.12-rc2 |
2662 |
*/ |
9eaef27b3 [PATCH] VFS: Make... |
2663 |
/* |
183675011 fix loop checks i... |
2664 |
* __d_move - move a dentry |
1da177e4c Linux-2.6.12-rc2 |
2665 2666 |
* @dentry: entry to move * @target: new dentry |
da1ce0670 vfs: add cross-re... |
2667 |
* @exchange: exchange the two dentries |
1da177e4c Linux-2.6.12-rc2 |
2668 2669 |
* * Update the dcache to reflect the move of a file name. Negative |
c46c88774 vfs: document loc... |
2670 2671 2672 |
* dcache entries should not be moved in this way. Caller must hold * rename_lock, the i_mutex of the source and target directories, * and the sb->s_vfs_rename_mutex if they differ. See lock_rename(). |
1da177e4c Linux-2.6.12-rc2 |
2673 |
*/ |
da1ce0670 vfs: add cross-re... |
2674 2675 |
static void __d_move(struct dentry *dentry, struct dentry *target, bool exchange) |
1da177e4c Linux-2.6.12-rc2 |
2676 |
{ |
84e710da2 parallel lookups ... |
2677 2678 |
struct inode *dir = NULL; unsigned n; |
1da177e4c Linux-2.6.12-rc2 |
2679 2680 2681 |
if (!dentry->d_inode) printk(KERN_WARNING "VFS: moving negative dcache entry "); |
2fd6b7f50 fs: dcache scale ... |
2682 2683 |
BUG_ON(d_ancestor(dentry, target)); BUG_ON(d_ancestor(target, dentry)); |
2fd6b7f50 fs: dcache scale ... |
2684 |
dentry_lock_for_move(dentry, target); |
84e710da2 parallel lookups ... |
2685 2686 2687 |
if (unlikely(d_in_lookup(target))) { dir = target->d_parent->d_inode; n = start_dir_add(dir); |
85c7f8104 beginning of tran... |
2688 |
__d_lookup_done(target); |
84e710da2 parallel lookups ... |
2689 |
} |
1da177e4c Linux-2.6.12-rc2 |
2690 |
|
31e6b01f4 fs: rcu-walk for ... |
2691 |
write_seqcount_begin(&dentry->d_seq); |
1ca7d67cf seqcount: Add loc... |
2692 |
write_seqcount_begin_nested(&target->d_seq, DENTRY_D_LOCK_NESTED); |
31e6b01f4 fs: rcu-walk for ... |
2693 |
|
15d3c589f fold _d_rehash() ... |
2694 |
/* unhash both */ |
ceb5bdc2d fs: dcache per-bu... |
2695 |
/* __d_drop does write_seqcount_barrier, but they're OK to nest. */ |
ceb5bdc2d fs: dcache per-bu... |
2696 |
__d_drop(dentry); |
1da177e4c Linux-2.6.12-rc2 |
2697 |
__d_drop(target); |
1da177e4c Linux-2.6.12-rc2 |
2698 |
/* Switch the names.. */ |
8d85b4845 Allow sharing ext... |
2699 2700 2701 2702 |
if (exchange) swap_names(dentry, target); else copy_name(dentry, target); |
1da177e4c Linux-2.6.12-rc2 |
2703 |
|
15d3c589f fold _d_rehash() ... |
2704 2705 2706 2707 |
/* rehash in new place(s) */ __d_rehash(dentry); if (exchange) __d_rehash(target); |
63cf427a5 kill __d_material... |
2708 |
/* ... and switch them in the tree */ |
1da177e4c Linux-2.6.12-rc2 |
2709 |
if (IS_ROOT(dentry)) { |
63cf427a5 kill __d_material... |
2710 |
/* splicing a tree */ |
3d56c25e3 fix d_walk()/non-... |
2711 |
dentry->d_flags |= DCACHE_RCUACCESS; |
1da177e4c Linux-2.6.12-rc2 |
2712 2713 |
dentry->d_parent = target->d_parent; target->d_parent = target; |
946e51f2b move d_rcu from o... |
2714 2715 |
list_del_init(&target->d_child); list_move(&dentry->d_child, &dentry->d_parent->d_subdirs); |
1da177e4c Linux-2.6.12-rc2 |
2716 |
} else { |
63cf427a5 kill __d_material... |
2717 |
/* swapping two dentries */ |
9a8d5bb4a generic swap(): d... |
2718 |
swap(dentry->d_parent, target->d_parent); |
946e51f2b move d_rcu from o... |
2719 2720 |
list_move(&target->d_child, &target->d_parent->d_subdirs); list_move(&dentry->d_child, &dentry->d_parent->d_subdirs); |
63cf427a5 kill __d_material... |
2721 |
if (exchange) |
affda4841 trim fsnotify hoo... |
2722 2723 |
fsnotify_update_flags(target); fsnotify_update_flags(dentry); |
1da177e4c Linux-2.6.12-rc2 |
2724 |
} |
31e6b01f4 fs: rcu-walk for ... |
2725 2726 |
write_seqcount_end(&target->d_seq); write_seqcount_end(&dentry->d_seq); |
84e710da2 parallel lookups ... |
2727 2728 |
if (dir) end_dir_add(dir, n); |
986c01942 fold unlocking th... |
2729 |
dentry_unlock_for_move(dentry, target); |
183675011 fix loop checks i... |
2730 2731 2732 2733 2734 2735 2736 2737 |
} /* * d_move - move a dentry * @dentry: entry to move * @target: new dentry * * Update the dcache to reflect the move of a file name. Negative |
c46c88774 vfs: document loc... |
2738 2739 |
* dcache entries should not be moved in this way. See the locking * requirements for __d_move. |
183675011 fix loop checks i... |
2740 2741 2742 2743 |
*/ void d_move(struct dentry *dentry, struct dentry *target) { write_seqlock(&rename_lock); |
da1ce0670 vfs: add cross-re... |
2744 |
__d_move(dentry, target, false); |
1da177e4c Linux-2.6.12-rc2 |
2745 |
write_sequnlock(&rename_lock); |
9eaef27b3 [PATCH] VFS: Make... |
2746 |
} |
ec4f86059 fs/dcache.c: Codi... |
2747 |
EXPORT_SYMBOL(d_move); |
1da177e4c Linux-2.6.12-rc2 |
2748 |
|
da1ce0670 vfs: add cross-re... |
2749 2750 2751 2752 2753 2754 2755 2756 2757 2758 2759 2760 2761 2762 2763 2764 2765 2766 |
/* * d_exchange - exchange two dentries * @dentry1: first dentry * @dentry2: second dentry */ void d_exchange(struct dentry *dentry1, struct dentry *dentry2) { write_seqlock(&rename_lock); WARN_ON(!dentry1->d_inode); WARN_ON(!dentry2->d_inode); WARN_ON(IS_ROOT(dentry1)); WARN_ON(IS_ROOT(dentry2)); __d_move(dentry1, dentry2, true); write_sequnlock(&rename_lock); } |
e2761a116 [PATCH vfs-2.6 2/... |
2767 2768 2769 2770 2771 2772 2773 |
/** * d_ancestor - search for an ancestor * @p1: ancestor dentry * @p2: child dentry * * Returns the ancestor dentry of p2 which is a child of p1, if p1 is * an ancestor of p2, else NULL. |
9eaef27b3 [PATCH] VFS: Make... |
2774 |
*/ |
e2761a116 [PATCH vfs-2.6 2/... |
2775 |
struct dentry *d_ancestor(struct dentry *p1, struct dentry *p2) |
9eaef27b3 [PATCH] VFS: Make... |
2776 2777 |
{ struct dentry *p; |
871c0067d [PATCH vfs-2.6 1/... |
2778 |
for (p = p2; !IS_ROOT(p); p = p->d_parent) { |
9eaef27b3 [PATCH] VFS: Make... |
2779 |
if (p->d_parent == p1) |
e2761a116 [PATCH vfs-2.6 2/... |
2780 |
return p; |
9eaef27b3 [PATCH] VFS: Make... |
2781 |
} |
e2761a116 [PATCH vfs-2.6 2/... |
2782 |
return NULL; |
9eaef27b3 [PATCH] VFS: Make... |
2783 2784 2785 2786 2787 2788 |
} /* * This helper attempts to cope with remotely renamed directories * * It assumes that the caller is already holding |
a03e283bf dcache: Reduce th... |
2789 |
* dentry->d_parent->d_inode->i_mutex, and rename_lock |
9eaef27b3 [PATCH] VFS: Make... |
2790 2791 2792 |
* * Note: If ever the locking in lock_rename() changes, then please * remember to update this too... |
9eaef27b3 [PATCH] VFS: Make... |
2793 |
*/ |
b5ae6b15b merge d_materiali... |
2794 |
static int __d_unalias(struct inode *inode, |
873feea09 fs: dcache per-in... |
2795 |
struct dentry *dentry, struct dentry *alias) |
9eaef27b3 [PATCH] VFS: Make... |
2796 |
{ |
9902af79c parallel lookups:... |
2797 2798 |
struct mutex *m1 = NULL; struct rw_semaphore *m2 = NULL; |
3d330dc17 dcache: return -E... |
2799 |
int ret = -ESTALE; |
9eaef27b3 [PATCH] VFS: Make... |
2800 2801 2802 2803 |
/* If alias and dentry share a parent, then no extra locks required */ if (alias->d_parent == dentry->d_parent) goto out_unalias; |
9eaef27b3 [PATCH] VFS: Make... |
2804 |
/* See lock_rename() */ |
9eaef27b3 [PATCH] VFS: Make... |
2805 2806 2807 |
if (!mutex_trylock(&dentry->d_sb->s_vfs_rename_mutex)) goto out_err; m1 = &dentry->d_sb->s_vfs_rename_mutex; |
9902af79c parallel lookups:... |
2808 |
if (!inode_trylock_shared(alias->d_parent->d_inode)) |
9eaef27b3 [PATCH] VFS: Make... |
2809 |
goto out_err; |
9902af79c parallel lookups:... |
2810 |
m2 = &alias->d_parent->d_inode->i_rwsem; |
9eaef27b3 [PATCH] VFS: Make... |
2811 |
out_unalias: |
8ed936b56 vfs: Lazily remov... |
2812 |
__d_move(alias, dentry, false); |
b5ae6b15b merge d_materiali... |
2813 |
ret = 0; |
9eaef27b3 [PATCH] VFS: Make... |
2814 |
out_err: |
9eaef27b3 [PATCH] VFS: Make... |
2815 |
if (m2) |
9902af79c parallel lookups:... |
2816 |
up_read(m2); |
9eaef27b3 [PATCH] VFS: Make... |
2817 2818 2819 2820 |
if (m1) mutex_unlock(m1); return ret; } |
770bfad84 NFS: Add dentry m... |
2821 |
/** |
3f70bd51c dcache: move d_sp... |
2822 2823 2824 2825 |
* d_splice_alias - splice a disconnected dentry into the tree if one exists * @inode: the inode which may have a disconnected dentry * @dentry: a negative dentry which we want to point to the inode. * |
da093a9b7 dcache: d_splice_... |
2826 2827 2828 |
* If inode is a directory and has an IS_ROOT alias, then d_move that in * place of the given dentry and return it, else simply d_add the inode * to the dentry and return NULL. |
3f70bd51c dcache: move d_sp... |
2829 |
* |
908790fa3 dcache: d_splice_... |
2830 2831 2832 |
* If a non-IS_ROOT directory is found, the filesystem is corrupt, and * we should error out: directories can't have multiple aliases. * |
3f70bd51c dcache: move d_sp... |
2833 2834 2835 2836 2837 2838 2839 2840 2841 2842 2843 2844 2845 |
* This is needed in the lookup routine of any filesystem that is exportable * (via knfsd) so that we can build dcache paths to directories effectively. * * If a dentry was found and moved, then it is returned. Otherwise NULL * is returned. This matches the expected return value of ->lookup. * * Cluster filesystems may call this function with a negative, hashed dentry. * In that case, we know that the inode will be a regular file, and also this * will only occur during atomic_open. So we need to check for the dentry * being already hashed only in the final case. */ struct dentry *d_splice_alias(struct inode *inode, struct dentry *dentry) { |
3f70bd51c dcache: move d_sp... |
2846 2847 |
if (IS_ERR(inode)) return ERR_CAST(inode); |
770bfad84 NFS: Add dentry m... |
2848 |
BUG_ON(!d_unhashed(dentry)); |
de689f5e3 don't bother with... |
2849 |
if (!inode) |
b5ae6b15b merge d_materiali... |
2850 |
goto out; |
de689f5e3 don't bother with... |
2851 |
|
b96809173 security_d_instan... |
2852 |
security_d_instantiate(dentry, inode); |
873feea09 fs: dcache per-in... |
2853 |
spin_lock(&inode->i_lock); |
9eaef27b3 [PATCH] VFS: Make... |
2854 |
if (S_ISDIR(inode->i_mode)) { |
b5ae6b15b merge d_materiali... |
2855 2856 |
struct dentry *new = __d_find_any_alias(inode); if (unlikely(new)) { |
a03e283bf dcache: Reduce th... |
2857 2858 |
/* The reference to new ensures it remains an alias */ spin_unlock(&inode->i_lock); |
183675011 fix loop checks i... |
2859 |
write_seqlock(&rename_lock); |
b5ae6b15b merge d_materiali... |
2860 2861 |
if (unlikely(d_ancestor(new, dentry))) { write_sequnlock(&rename_lock); |
b5ae6b15b merge d_materiali... |
2862 2863 2864 2865 2866 2867 2868 2869 2870 2871 2872 |
dput(new); new = ERR_PTR(-ELOOP); pr_warn_ratelimited( "VFS: Lookup of '%s' in %s %s" " would have caused loop ", dentry->d_name.name, inode->i_sb->s_type->name, inode->i_sb->s_id); } else if (!IS_ROOT(new)) { int err = __d_unalias(inode, dentry, new); |
183675011 fix loop checks i... |
2873 |
write_sequnlock(&rename_lock); |
b5ae6b15b merge d_materiali... |
2874 2875 2876 2877 |
if (err) { dput(new); new = ERR_PTR(err); } |
183675011 fix loop checks i... |
2878 |
} else { |
b5ae6b15b merge d_materiali... |
2879 2880 |
__d_move(new, dentry, false); write_sequnlock(&rename_lock); |
dd179946d VFS: Log the fact... |
2881 |
} |
b5ae6b15b merge d_materiali... |
2882 2883 |
iput(inode); return new; |
9eaef27b3 [PATCH] VFS: Make... |
2884 |
} |
770bfad84 NFS: Add dentry m... |
2885 |
} |
b5ae6b15b merge d_materiali... |
2886 |
out: |
ed782b5a7 dcache.c: new hel... |
2887 |
__d_add(dentry, inode); |
b5ae6b15b merge d_materiali... |
2888 |
return NULL; |
770bfad84 NFS: Add dentry m... |
2889 |
} |
b5ae6b15b merge d_materiali... |
2890 |
EXPORT_SYMBOL(d_splice_alias); |
770bfad84 NFS: Add dentry m... |
2891 |
|
cdd16d026 [patch 2/3] vfs: ... |
2892 |
static int prepend(char **buffer, int *buflen, const char *str, int namelen) |
6092d0481 [patch 1/7] vfs: ... |
2893 2894 2895 2896 2897 2898 2899 2900 |
{ *buflen -= namelen; if (*buflen < 0) return -ENAMETOOLONG; *buffer -= namelen; memcpy(*buffer, str, namelen); return 0; } |
232d2d60a dcache: Translati... |
2901 2902 |
/** * prepend_name - prepend a pathname in front of current buffer pointer |
181299772 dcache: get/relea... |
2903 2904 2905 |
* @buffer: buffer pointer * @buflen: allocated length of the buffer * @name: name string and length qstr structure |
232d2d60a dcache: Translati... |
2906 2907 2908 2909 2910 2911 2912 2913 2914 |
* * With RCU path tracing, it may race with d_move(). Use ACCESS_ONCE() to * make sure that either the old or the new name pointer and length are * fetched. However, there may be mismatch between length and pointer. * The length cannot be trusted, we need to copy it byte-by-byte until * the length is reached or a null byte is found. It also prepends "/" at * the beginning of the name. The sequence number check at the caller will * retry it again when a d_move() does happen. So any garbage in the buffer * due to mismatched pointer and length will be discarded. |
6d13f6944 missing data depe... |
2915 2916 2917 |
* * Data dependency barrier is needed to make sure that we see that terminating * NUL. Alpha strikes again, film at 11... |
232d2d60a dcache: Translati... |
2918 |
*/ |
9aba36dea qstr constify ins... |
2919 |
static int prepend_name(char **buffer, int *buflen, const struct qstr *name) |
cdd16d026 [patch 2/3] vfs: ... |
2920 |
{ |
232d2d60a dcache: Translati... |
2921 2922 2923 |
const char *dname = ACCESS_ONCE(name->name); u32 dlen = ACCESS_ONCE(name->len); char *p; |
6d13f6944 missing data depe... |
2924 |
smp_read_barrier_depends(); |
232d2d60a dcache: Translati... |
2925 |
*buflen -= dlen + 1; |
e825196d4 make prepend_name... |
2926 2927 |
if (*buflen < 0) return -ENAMETOOLONG; |
232d2d60a dcache: Translati... |
2928 2929 2930 2931 2932 2933 2934 2935 2936 |
p = *buffer -= dlen + 1; *p++ = '/'; while (dlen--) { char c = *dname++; if (!c) break; *p++ = c; } return 0; |
cdd16d026 [patch 2/3] vfs: ... |
2937 |
} |
1da177e4c Linux-2.6.12-rc2 |
2938 |
/** |
208898c17 fs: fix kernel-do... |
2939 |
* prepend_path - Prepend path string to a buffer |
9d1bc6013 [patch 2/7] vfs: ... |
2940 |
* @path: the dentry/vfsmount to report |
02125a826 fix apparmor dere... |
2941 |
* @root: root vfsmnt/dentry |
f2eb6575d vfs: add prepend_... |
2942 2943 |
* @buffer: pointer to the end of the buffer * @buflen: pointer to buffer length |
552ce544e Revert "[PATCH] F... |
2944 |
* |
181299772 dcache: get/relea... |
2945 2946 2947 2948 2949 2950 2951 2952 2953 |
* The function will first try to write out the pathname without taking any * lock other than the RCU read lock to make sure that dentries won't go away. * It only checks the sequence number of the global rename_lock as any change * in the dentry's d_seq will be preceded by changes in the rename_lock * sequence number. If the sequence number had been changed, it will restart * the whole pathname back-tracing sequence again by taking the rename_lock. * In this case, there is no need to take the RCU read lock as the recursive * parent pointer references will keep the dentry chain alive as long as no * rename operation is performed. |
1da177e4c Linux-2.6.12-rc2 |
2954 |
*/ |
02125a826 fix apparmor dere... |
2955 2956 |
static int prepend_path(const struct path *path, const struct path *root, |
f2eb6575d vfs: add prepend_... |
2957 |
char **buffer, int *buflen) |
1da177e4c Linux-2.6.12-rc2 |
2958 |
{ |
ede4cebce prepend_path() ne... |
2959 2960 2961 |
struct dentry *dentry; struct vfsmount *vfsmnt; struct mount *mnt; |
f2eb6575d vfs: add prepend_... |
2962 |
int error = 0; |
48a066e72 RCU'd vfsmounts |
2963 |
unsigned seq, m_seq = 0; |
232d2d60a dcache: Translati... |
2964 2965 |
char *bptr; int blen; |
6092d0481 [patch 1/7] vfs: ... |
2966 |
|
48f5ec21d split read_seqret... |
2967 |
rcu_read_lock(); |
48a066e72 RCU'd vfsmounts |
2968 2969 2970 |
restart_mnt: read_seqbegin_or_lock(&mount_lock, &m_seq); seq = 0; |
4ec6c2aea fix unpaired rcu ... |
2971 |
rcu_read_lock(); |
232d2d60a dcache: Translati... |
2972 2973 2974 |
restart: bptr = *buffer; blen = *buflen; |
48a066e72 RCU'd vfsmounts |
2975 |
error = 0; |
ede4cebce prepend_path() ne... |
2976 2977 2978 |
dentry = path->dentry; vfsmnt = path->mnt; mnt = real_mount(vfsmnt); |
232d2d60a dcache: Translati... |
2979 |
read_seqbegin_or_lock(&rename_lock, &seq); |
f2eb6575d vfs: add prepend_... |
2980 |
while (dentry != root->dentry || vfsmnt != root->mnt) { |
1da177e4c Linux-2.6.12-rc2 |
2981 |
struct dentry * parent; |
1da177e4c Linux-2.6.12-rc2 |
2982 |
if (dentry == vfsmnt->mnt_root || IS_ROOT(dentry)) { |
48a066e72 RCU'd vfsmounts |
2983 |
struct mount *parent = ACCESS_ONCE(mnt->mnt_parent); |
cde93be45 dcache: Handle es... |
2984 2985 2986 2987 2988 2989 2990 |
/* Escaped? */ if (dentry != vfsmnt->mnt_root) { bptr = *buffer; blen = *buflen; error = 3; break; } |
552ce544e Revert "[PATCH] F... |
2991 |
/* Global root? */ |
48a066e72 RCU'd vfsmounts |
2992 2993 2994 |
if (mnt != parent) { dentry = ACCESS_ONCE(mnt->mnt_mountpoint); mnt = parent; |
232d2d60a dcache: Translati... |
2995 2996 2997 |
vfsmnt = &mnt->mnt; continue; } |
232d2d60a dcache: Translati... |
2998 2999 3000 |
if (!error) error = is_mounted(vfsmnt) ? 1 : 2; break; |
1da177e4c Linux-2.6.12-rc2 |
3001 3002 3003 |
} parent = dentry->d_parent; prefetch(parent); |
232d2d60a dcache: Translati... |
3004 |
error = prepend_name(&bptr, &blen, &dentry->d_name); |
f2eb6575d vfs: add prepend_... |
3005 3006 |
if (error) break; |
1da177e4c Linux-2.6.12-rc2 |
3007 3008 |
dentry = parent; } |
48f5ec21d split read_seqret... |
3009 3010 3011 3012 |
if (!(seq & 1)) rcu_read_unlock(); if (need_seqretry(&rename_lock, seq)) { seq = 1; |
232d2d60a dcache: Translati... |
3013 |
goto restart; |
48f5ec21d split read_seqret... |
3014 3015 |
} done_seqretry(&rename_lock, seq); |
4ec6c2aea fix unpaired rcu ... |
3016 3017 3018 |
if (!(m_seq & 1)) rcu_read_unlock(); |
48a066e72 RCU'd vfsmounts |
3019 3020 3021 3022 3023 |
if (need_seqretry(&mount_lock, m_seq)) { m_seq = 1; goto restart_mnt; } done_seqretry(&mount_lock, m_seq); |
1da177e4c Linux-2.6.12-rc2 |
3024 |
|
232d2d60a dcache: Translati... |
3025 3026 3027 3028 3029 3030 3031 3032 |
if (error >= 0 && bptr == *buffer) { if (--blen < 0) error = -ENAMETOOLONG; else *--bptr = '/'; } *buffer = bptr; *buflen = blen; |
7ea600b53 Nest rename_lock ... |
3033 |
return error; |
f2eb6575d vfs: add prepend_... |
3034 |
} |
be285c712 [patch 3/3] vfs: ... |
3035 |
|
f2eb6575d vfs: add prepend_... |
3036 3037 3038 |
/** * __d_path - return the path of a dentry * @path: the dentry/vfsmount to report |
02125a826 fix apparmor dere... |
3039 |
* @root: root vfsmnt/dentry |
cd956a1c0 fs/dcache: fix fu... |
3040 |
* @buf: buffer to return value in |
f2eb6575d vfs: add prepend_... |
3041 3042 |
* @buflen: buffer length * |
ffd1f4ed5 vfs: only add " (... |
3043 |
* Convert a dentry into an ASCII path name. |
f2eb6575d vfs: add prepend_... |
3044 3045 3046 3047 |
* * Returns a pointer into the buffer or an error code if the * path was too long. * |
be148247c fs: take dcache_l... |
3048 |
* "buflen" should be positive. |
f2eb6575d vfs: add prepend_... |
3049 |
* |
02125a826 fix apparmor dere... |
3050 |
* If the path is not reachable from the supplied root, return %NULL. |
f2eb6575d vfs: add prepend_... |
3051 |
*/ |
02125a826 fix apparmor dere... |
3052 3053 |
char *__d_path(const struct path *path, const struct path *root, |
f2eb6575d vfs: add prepend_... |
3054 3055 3056 3057 3058 3059 |
char *buf, int buflen) { char *res = buf + buflen; int error; prepend(&res, &buflen, "\0", 1); |
f2eb6575d vfs: add prepend_... |
3060 |
error = prepend_path(path, root, &res, &buflen); |
be148247c fs: take dcache_l... |
3061 |
|
02125a826 fix apparmor dere... |
3062 3063 3064 3065 3066 3067 3068 3069 3070 3071 3072 3073 3074 3075 3076 |
if (error < 0) return ERR_PTR(error); if (error > 0) return NULL; return res; } char *d_absolute_path(const struct path *path, char *buf, int buflen) { struct path root = {}; char *res = buf + buflen; int error; prepend(&res, &buflen, "\0", 1); |
02125a826 fix apparmor dere... |
3077 |
error = prepend_path(path, &root, &res, &buflen); |
02125a826 fix apparmor dere... |
3078 3079 3080 3081 |
if (error > 1) error = -EINVAL; if (error < 0) |
f2eb6575d vfs: add prepend_... |
3082 |
return ERR_PTR(error); |
f2eb6575d vfs: add prepend_... |
3083 |
return res; |
1da177e4c Linux-2.6.12-rc2 |
3084 |
} |
ffd1f4ed5 vfs: only add " (... |
3085 3086 3087 |
/* * same as __d_path but appends "(deleted)" for unlinked files. */ |
02125a826 fix apparmor dere... |
3088 3089 3090 |
static int path_with_deleted(const struct path *path, const struct path *root, char **buf, int *buflen) |
ffd1f4ed5 vfs: only add " (... |
3091 3092 3093 3094 3095 3096 3097 3098 3099 3100 |
{ prepend(buf, buflen, "\0", 1); if (d_unlinked(path->dentry)) { int error = prepend(buf, buflen, " (deleted)", 10); if (error) return error; } return prepend_path(path, root, buf, buflen); } |
8df9d1a41 vfs: show unreach... |
3101 3102 3103 3104 |
static int prepend_unreachable(char **buffer, int *buflen) { return prepend(buffer, buflen, "(unreachable)", 13); } |
68f0d9d92 vfs: make d_path(... |
3105 3106 3107 3108 3109 3110 3111 3112 3113 |
static void get_fs_root_rcu(struct fs_struct *fs, struct path *root) { unsigned seq; do { seq = read_seqcount_begin(&fs->seq); *root = fs->root; } while (read_seqcount_retry(&fs->seq, seq)); } |
a03a8a709 d_path: kerneldoc... |
3114 3115 |
/** * d_path - return the path of a dentry |
cf28b4863 d_path: Make d_pa... |
3116 |
* @path: path to report |
a03a8a709 d_path: kerneldoc... |
3117 3118 3119 3120 3121 3122 |
* @buf: buffer to return value in * @buflen: buffer length * * Convert a dentry into an ASCII path name. If the entry has been deleted * the string " (deleted)" is appended. Note that this is ambiguous. * |
52afeefb9 expand some comme... |
3123 3124 3125 3126 |
* Returns a pointer into the buffer or an error code if the path was * too long. Note: Callers should use the returned pointer, not the passed * in buffer, to use the name! The implementation often starts at an offset * into the buffer, and may leave 0 bytes at the start. |
a03a8a709 d_path: kerneldoc... |
3127 |
* |
31f3e0b3a [patch 1/3] vfs: ... |
3128 |
* "buflen" should be positive. |
a03a8a709 d_path: kerneldoc... |
3129 |
*/ |
20d4fdc1a [patch 2/4] fs: m... |
3130 |
char *d_path(const struct path *path, char *buf, int buflen) |
1da177e4c Linux-2.6.12-rc2 |
3131 |
{ |
ffd1f4ed5 vfs: only add " (... |
3132 |
char *res = buf + buflen; |
6ac08c39a Use struct path i... |
3133 |
struct path root; |
ffd1f4ed5 vfs: only add " (... |
3134 |
int error; |
1da177e4c Linux-2.6.12-rc2 |
3135 |
|
c23fbb6bc VFS: delay the de... |
3136 3137 3138 3139 3140 3141 |
/* * We have various synthetic filesystems that never get mounted. On * these filesystems dentries are never used for lookup purposes, and * thus don't need to be hashed. They also don't need a name until a * user wants to identify the object in /proc/pid/fd/. The little hack * below allows us to generate a name for these objects on demand: |
f48cfddc6 vfs: In d_path do... |
3142 3143 3144 3145 |
* * Some pseudo inodes are mountable. When they are mounted * path->dentry == path->mnt->mnt_root. In that case don't call d_dname * and instead have d_path return the mounted path. |
c23fbb6bc VFS: delay the de... |
3146 |
*/ |
f48cfddc6 vfs: In d_path do... |
3147 3148 |
if (path->dentry->d_op && path->dentry->d_op->d_dname && (!IS_ROOT(path->dentry) || path->dentry != path->mnt->mnt_root)) |
cf28b4863 d_path: Make d_pa... |
3149 |
return path->dentry->d_op->d_dname(path->dentry, buf, buflen); |
c23fbb6bc VFS: delay the de... |
3150 |
|
68f0d9d92 vfs: make d_path(... |
3151 3152 |
rcu_read_lock(); get_fs_root_rcu(current->fs, &root); |
02125a826 fix apparmor dere... |
3153 |
error = path_with_deleted(path, &root, &res, &buflen); |
68f0d9d92 vfs: make d_path(... |
3154 |
rcu_read_unlock(); |
02125a826 fix apparmor dere... |
3155 |
if (error < 0) |
ffd1f4ed5 vfs: only add " (... |
3156 |
res = ERR_PTR(error); |
1da177e4c Linux-2.6.12-rc2 |
3157 3158 |
return res; } |
ec4f86059 fs/dcache.c: Codi... |
3159 |
EXPORT_SYMBOL(d_path); |
1da177e4c Linux-2.6.12-rc2 |
3160 3161 |
/* |
c23fbb6bc VFS: delay the de... |
3162 3163 3164 3165 3166 3167 3168 3169 3170 3171 3172 3173 3174 3175 3176 3177 3178 3179 3180 |
* Helper function for dentry_operations.d_dname() members */ char *dynamic_dname(struct dentry *dentry, char *buffer, int buflen, const char *fmt, ...) { va_list args; char temp[64]; int sz; va_start(args, fmt); sz = vsnprintf(temp, sizeof(temp), fmt, args) + 1; va_end(args); if (sz > sizeof(temp) || sz > buflen) return ERR_PTR(-ENAMETOOLONG); buffer += buflen - sz; return memcpy(buffer, temp, sz); } |
118b23022 cope with potenti... |
3181 3182 3183 3184 3185 |
char *simple_dname(struct dentry *dentry, char *buffer, int buflen) { char *end = buffer + buflen; /* these dentries are never renamed, so d_lock is not needed */ if (prepend(&end, &buflen, " (deleted)", 11) || |
232d2d60a dcache: Translati... |
3186 |
prepend(&end, &buflen, dentry->d_name.name, dentry->d_name.len) || |
118b23022 cope with potenti... |
3187 3188 |
prepend(&end, &buflen, "/", 1)) end = ERR_PTR(-ENAMETOOLONG); |
232d2d60a dcache: Translati... |
3189 |
return end; |
118b23022 cope with potenti... |
3190 |
} |
31bbe16f6 drm: add pseudo f... |
3191 |
EXPORT_SYMBOL(simple_dname); |
118b23022 cope with potenti... |
3192 |
|
c23fbb6bc VFS: delay the de... |
3193 |
/* |
6092d0481 [patch 1/7] vfs: ... |
3194 3195 |
* Write full pathname from the root of the filesystem into the buffer. */ |
f65008015 __dentry_path() f... |
3196 |
static char *__dentry_path(struct dentry *d, char *buf, int buflen) |
6092d0481 [patch 1/7] vfs: ... |
3197 |
{ |
f65008015 __dentry_path() f... |
3198 |
struct dentry *dentry; |
232d2d60a dcache: Translati... |
3199 3200 3201 |
char *end, *retval; int len, seq = 0; int error = 0; |
6092d0481 [patch 1/7] vfs: ... |
3202 |
|
f65008015 __dentry_path() f... |
3203 3204 |
if (buflen < 2) goto Elong; |
48f5ec21d split read_seqret... |
3205 |
rcu_read_lock(); |
232d2d60a dcache: Translati... |
3206 |
restart: |
f65008015 __dentry_path() f... |
3207 |
dentry = d; |
232d2d60a dcache: Translati... |
3208 3209 3210 |
end = buf + buflen; len = buflen; prepend(&end, &len, "\0", 1); |
6092d0481 [patch 1/7] vfs: ... |
3211 3212 3213 |
/* Get '/' right */ retval = end-1; *retval = '/'; |
232d2d60a dcache: Translati... |
3214 |
read_seqbegin_or_lock(&rename_lock, &seq); |
cdd16d026 [patch 2/3] vfs: ... |
3215 3216 |
while (!IS_ROOT(dentry)) { struct dentry *parent = dentry->d_parent; |
6092d0481 [patch 1/7] vfs: ... |
3217 |
|
6092d0481 [patch 1/7] vfs: ... |
3218 |
prefetch(parent); |
232d2d60a dcache: Translati... |
3219 3220 3221 |
error = prepend_name(&end, &len, &dentry->d_name); if (error) break; |
6092d0481 [patch 1/7] vfs: ... |
3222 3223 3224 3225 |
retval = end; dentry = parent; } |
48f5ec21d split read_seqret... |
3226 3227 3228 3229 |
if (!(seq & 1)) rcu_read_unlock(); if (need_seqretry(&rename_lock, seq)) { seq = 1; |
232d2d60a dcache: Translati... |
3230 |
goto restart; |
48f5ec21d split read_seqret... |
3231 3232 |
} done_seqretry(&rename_lock, seq); |
232d2d60a dcache: Translati... |
3233 3234 |
if (error) goto Elong; |
c103135c1 new helper: __den... |
3235 3236 3237 3238 |
return retval; Elong: return ERR_PTR(-ENAMETOOLONG); } |
ec2447c27 hostfs: simplify ... |
3239 3240 3241 |
char *dentry_path_raw(struct dentry *dentry, char *buf, int buflen) { |
232d2d60a dcache: Translati... |
3242 |
return __dentry_path(dentry, buf, buflen); |
ec2447c27 hostfs: simplify ... |
3243 3244 |
} EXPORT_SYMBOL(dentry_path_raw); |
c103135c1 new helper: __den... |
3245 3246 3247 3248 3249 |
char *dentry_path(struct dentry *dentry, char *buf, int buflen) { char *p = NULL; char *retval; |
c103135c1 new helper: __den... |
3250 3251 3252 3253 3254 3255 3256 |
if (d_unlinked(dentry)) { p = buf + buflen; if (prepend(&p, &buflen, "//deleted", 10) != 0) goto Elong; buflen++; } retval = __dentry_path(dentry, buf, buflen); |
c103135c1 new helper: __den... |
3257 3258 |
if (!IS_ERR(retval) && p) *p = '/'; /* restore '/' overriden with '\0' */ |
6092d0481 [patch 1/7] vfs: ... |
3259 3260 |
return retval; Elong: |
6092d0481 [patch 1/7] vfs: ... |
3261 3262 |
return ERR_PTR(-ENAMETOOLONG); } |
8b19e3418 vfs: make getcwd(... |
3263 3264 |
static void get_fs_root_and_pwd_rcu(struct fs_struct *fs, struct path *root, struct path *pwd) |
5762482f5 vfs: move get_fs_... |
3265 |
{ |
8b19e3418 vfs: make getcwd(... |
3266 3267 3268 3269 3270 3271 3272 |
unsigned seq; do { seq = read_seqcount_begin(&fs->seq); *root = fs->root; *pwd = fs->pwd; } while (read_seqcount_retry(&fs->seq, seq)); |
5762482f5 vfs: move get_fs_... |
3273 |
} |
6092d0481 [patch 1/7] vfs: ... |
3274 |
/* |
1da177e4c Linux-2.6.12-rc2 |
3275 3276 3277 3278 3279 3280 3281 3282 3283 3284 3285 3286 3287 3288 3289 3290 3291 |
* NOTE! The user-level library version returns a * character pointer. The kernel system call just * returns the length of the buffer filled (which * includes the ending '\0' character), or a negative * error value. So libc would do something like * * char *getcwd(char * buf, size_t size) * { * int retval; * * retval = sys_getcwd(buf, size); * if (retval >= 0) * return buf; * errno = -retval; * return NULL; * } */ |
3cdad4288 [CVE-2009-0029] S... |
3292 |
SYSCALL_DEFINE2(getcwd, char __user *, buf, unsigned long, size) |
1da177e4c Linux-2.6.12-rc2 |
3293 |
{ |
552ce544e Revert "[PATCH] F... |
3294 |
int error; |
6ac08c39a Use struct path i... |
3295 |
struct path pwd, root; |
3272c544d vfs: use __getnam... |
3296 |
char *page = __getname(); |
1da177e4c Linux-2.6.12-rc2 |
3297 3298 3299 |
if (!page) return -ENOMEM; |
8b19e3418 vfs: make getcwd(... |
3300 3301 |
rcu_read_lock(); get_fs_root_and_pwd_rcu(current->fs, &root, &pwd); |
1da177e4c Linux-2.6.12-rc2 |
3302 |
|
552ce544e Revert "[PATCH] F... |
3303 |
error = -ENOENT; |
f3da392e9 dcache: extrace a... |
3304 |
if (!d_unlinked(pwd.dentry)) { |
552ce544e Revert "[PATCH] F... |
3305 |
unsigned long len; |
3272c544d vfs: use __getnam... |
3306 3307 |
char *cwd = page + PATH_MAX; int buflen = PATH_MAX; |
1da177e4c Linux-2.6.12-rc2 |
3308 |
|
8df9d1a41 vfs: show unreach... |
3309 |
prepend(&cwd, &buflen, "\0", 1); |
02125a826 fix apparmor dere... |
3310 |
error = prepend_path(&pwd, &root, &cwd, &buflen); |
ff812d724 vfs: don't copy t... |
3311 |
rcu_read_unlock(); |
552ce544e Revert "[PATCH] F... |
3312 |
|
02125a826 fix apparmor dere... |
3313 |
if (error < 0) |
552ce544e Revert "[PATCH] F... |
3314 |
goto out; |
8df9d1a41 vfs: show unreach... |
3315 |
/* Unreachable from current root */ |
02125a826 fix apparmor dere... |
3316 |
if (error > 0) { |
8df9d1a41 vfs: show unreach... |
3317 3318 3319 3320 |
error = prepend_unreachable(&cwd, &buflen); if (error) goto out; } |
552ce544e Revert "[PATCH] F... |
3321 |
error = -ERANGE; |
3272c544d vfs: use __getnam... |
3322 |
len = PATH_MAX + page - cwd; |
552ce544e Revert "[PATCH] F... |
3323 3324 3325 3326 3327 |
if (len <= size) { error = len; if (copy_to_user(buf, cwd, len)) error = -EFAULT; } |
949854d02 fs: Use rename lo... |
3328 |
} else { |
ff812d724 vfs: don't copy t... |
3329 |
rcu_read_unlock(); |
949854d02 fs: Use rename lo... |
3330 |
} |
1da177e4c Linux-2.6.12-rc2 |
3331 3332 |
out: |
3272c544d vfs: use __getnam... |
3333 |
__putname(page); |
1da177e4c Linux-2.6.12-rc2 |
3334 3335 3336 3337 3338 3339 3340 3341 3342 3343 3344 3345 3346 3347 |
return error; } /* * Test whether new_dentry is a subdirectory of old_dentry. * * Trivially implemented using the dcache structure */ /** * is_subdir - is new dentry a subdirectory of old_dentry * @new_dentry: new dentry * @old_dentry: old dentry * |
a6e5787fc fs/dcache.c: is_s... |
3348 3349 |
* Returns true if new_dentry is a subdirectory of the parent (at any depth). * Returns false otherwise. |
1da177e4c Linux-2.6.12-rc2 |
3350 3351 3352 |
* Caller must ensure that "new_dentry" is pinned before calling is_subdir() */ |
a6e5787fc fs/dcache.c: is_s... |
3353 |
bool is_subdir(struct dentry *new_dentry, struct dentry *old_dentry) |
1da177e4c Linux-2.6.12-rc2 |
3354 |
{ |
a6e5787fc fs/dcache.c: is_s... |
3355 |
bool result; |
949854d02 fs: Use rename lo... |
3356 |
unsigned seq; |
1da177e4c Linux-2.6.12-rc2 |
3357 |
|
e2761a116 [PATCH vfs-2.6 2/... |
3358 |
if (new_dentry == old_dentry) |
a6e5787fc fs/dcache.c: is_s... |
3359 |
return true; |
e2761a116 [PATCH vfs-2.6 2/... |
3360 |
|
e2761a116 [PATCH vfs-2.6 2/... |
3361 |
do { |
1da177e4c Linux-2.6.12-rc2 |
3362 |
/* for restarting inner loop in case of seq retry */ |
1da177e4c Linux-2.6.12-rc2 |
3363 |
seq = read_seqbegin(&rename_lock); |
949854d02 fs: Use rename lo... |
3364 3365 3366 3367 3368 |
/* * Need rcu_readlock to protect against the d_parent trashing * due to d_move */ rcu_read_lock(); |
e2761a116 [PATCH vfs-2.6 2/... |
3369 |
if (d_ancestor(old_dentry, new_dentry)) |
a6e5787fc fs/dcache.c: is_s... |
3370 |
result = true; |
e2761a116 [PATCH vfs-2.6 2/... |
3371 |
else |
a6e5787fc fs/dcache.c: is_s... |
3372 |
result = false; |
949854d02 fs: Use rename lo... |
3373 |
rcu_read_unlock(); |
1da177e4c Linux-2.6.12-rc2 |
3374 |
} while (read_seqretry(&rename_lock, seq)); |
1da177e4c Linux-2.6.12-rc2 |
3375 3376 3377 |
return result; } |
db14fc3ab vfs: add d_walk() |
3378 |
static enum d_walk_ret d_genocide_kill(void *data, struct dentry *dentry) |
1da177e4c Linux-2.6.12-rc2 |
3379 |
{ |
db14fc3ab vfs: add d_walk() |
3380 3381 3382 3383 |
struct dentry *root = data; if (dentry != root) { if (d_unhashed(dentry) || !dentry->d_inode) return D_WALK_SKIP; |
1da177e4c Linux-2.6.12-rc2 |
3384 |
|
01ddc4ede vfs: restructure ... |
3385 3386 3387 3388 |
if (!(dentry->d_flags & DCACHE_GENOCIDE)) { dentry->d_flags |= DCACHE_GENOCIDE; dentry->d_lockref.count--; } |
1da177e4c Linux-2.6.12-rc2 |
3389 |
} |
db14fc3ab vfs: add d_walk() |
3390 3391 |
return D_WALK_CONTINUE; } |
58db63d08 fs: dcache avoid ... |
3392 |
|
db14fc3ab vfs: add d_walk() |
3393 3394 3395 |
void d_genocide(struct dentry *parent) { d_walk(parent, parent, d_genocide_kill, NULL); |
1da177e4c Linux-2.6.12-rc2 |
3396 |
} |
60545d0d4 [O_TMPFILE] it's ... |
3397 |
void d_tmpfile(struct dentry *dentry, struct inode *inode) |
1da177e4c Linux-2.6.12-rc2 |
3398 |
{ |
60545d0d4 [O_TMPFILE] it's ... |
3399 3400 |
inode_dec_link_count(inode); BUG_ON(dentry->d_name.name != dentry->d_iname || |
946e51f2b move d_rcu from o... |
3401 |
!hlist_unhashed(&dentry->d_u.d_alias) || |
60545d0d4 [O_TMPFILE] it's ... |
3402 3403 3404 3405 3406 3407 3408 3409 |
!d_unlinked(dentry)); spin_lock(&dentry->d_parent->d_lock); spin_lock_nested(&dentry->d_lock, DENTRY_D_LOCK_NESTED); dentry->d_name.len = sprintf(dentry->d_iname, "#%llu", (unsigned long long)inode->i_ino); spin_unlock(&dentry->d_lock); spin_unlock(&dentry->d_parent->d_lock); d_instantiate(dentry, inode); |
1da177e4c Linux-2.6.12-rc2 |
3410 |
} |
60545d0d4 [O_TMPFILE] it's ... |
3411 |
EXPORT_SYMBOL(d_tmpfile); |
1da177e4c Linux-2.6.12-rc2 |
3412 3413 3414 3415 3416 3417 3418 3419 3420 3421 3422 3423 3424 |
static __initdata unsigned long dhash_entries; static int __init set_dhash_entries(char *str) { if (!str) return 0; dhash_entries = simple_strtoul(str, &str, 0); return 1; } __setup("dhash_entries=", set_dhash_entries); static void __init dcache_init_early(void) { |
074b85175 vfs: fix panic in... |
3425 |
unsigned int loop; |
1da177e4c Linux-2.6.12-rc2 |
3426 3427 3428 3429 3430 3431 3432 3433 3434 |
/* If hashes are distributed across NUMA nodes, defer * hash allocation until vmalloc space is available. */ if (hashdist) return; dentry_hashtable = alloc_large_system_hash("Dentry cache", |
b07ad9967 vfs: get rid of '... |
3435 |
sizeof(struct hlist_bl_head), |
1da177e4c Linux-2.6.12-rc2 |
3436 3437 3438 3439 3440 |
dhash_entries, 13, HASH_EARLY, &d_hash_shift, &d_hash_mask, |
31fe62b95 mm: add a low lim... |
3441 |
0, |
1da177e4c Linux-2.6.12-rc2 |
3442 |
0); |
074b85175 vfs: fix panic in... |
3443 |
for (loop = 0; loop < (1U << d_hash_shift); loop++) |
b07ad9967 vfs: get rid of '... |
3444 |
INIT_HLIST_BL_HEAD(dentry_hashtable + loop); |
1da177e4c Linux-2.6.12-rc2 |
3445 |
} |
74bf17cff fs: remove the un... |
3446 |
static void __init dcache_init(void) |
1da177e4c Linux-2.6.12-rc2 |
3447 |
{ |
074b85175 vfs: fix panic in... |
3448 |
unsigned int loop; |
1da177e4c Linux-2.6.12-rc2 |
3449 3450 3451 3452 3453 3454 |
/* * A constructor could be added for stable state like the lists, * but it is probably not worth it because of the cache nature * of the dcache. */ |
0a31bd5f2 KMEM_CACHE(): sim... |
3455 |
dentry_cache = KMEM_CACHE(dentry, |
5d097056c kmemcg: account c... |
3456 |
SLAB_RECLAIM_ACCOUNT|SLAB_PANIC|SLAB_MEM_SPREAD|SLAB_ACCOUNT); |
1da177e4c Linux-2.6.12-rc2 |
3457 3458 3459 3460 3461 3462 3463 |
/* Hash may have been set up in dcache_init_early */ if (!hashdist) return; dentry_hashtable = alloc_large_system_hash("Dentry cache", |
b07ad9967 vfs: get rid of '... |
3464 |
sizeof(struct hlist_bl_head), |
1da177e4c Linux-2.6.12-rc2 |
3465 3466 3467 3468 3469 |
dhash_entries, 13, 0, &d_hash_shift, &d_hash_mask, |
31fe62b95 mm: add a low lim... |
3470 |
0, |
1da177e4c Linux-2.6.12-rc2 |
3471 |
0); |
074b85175 vfs: fix panic in... |
3472 |
for (loop = 0; loop < (1U << d_hash_shift); loop++) |
b07ad9967 vfs: get rid of '... |
3473 |
INIT_HLIST_BL_HEAD(dentry_hashtable + loop); |
1da177e4c Linux-2.6.12-rc2 |
3474 3475 3476 |
} /* SLAB cache for __getname() consumers */ |
e18b890bb [PATCH] slab: rem... |
3477 |
struct kmem_cache *names_cachep __read_mostly; |
ec4f86059 fs/dcache.c: Codi... |
3478 |
EXPORT_SYMBOL(names_cachep); |
1da177e4c Linux-2.6.12-rc2 |
3479 |
|
1da177e4c Linux-2.6.12-rc2 |
3480 |
EXPORT_SYMBOL(d_genocide); |
1da177e4c Linux-2.6.12-rc2 |
3481 3482 3483 3484 3485 |
void __init vfs_caches_init_early(void) { dcache_init_early(); inode_init_early(); } |
4248b0da4 fs, file table: r... |
3486 |
void __init vfs_caches_init(void) |
1da177e4c Linux-2.6.12-rc2 |
3487 |
{ |
1da177e4c Linux-2.6.12-rc2 |
3488 |
names_cachep = kmem_cache_create("names_cache", PATH_MAX, 0, |
20c2df83d mm: Remove slab d... |
3489 |
SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL); |
1da177e4c Linux-2.6.12-rc2 |
3490 |
|
74bf17cff fs: remove the un... |
3491 3492 |
dcache_init(); inode_init(); |
4248b0da4 fs, file table: r... |
3493 3494 |
files_init(); files_maxfiles_init(); |
74bf17cff fs: remove the un... |
3495 |
mnt_init(); |
1da177e4c Linux-2.6.12-rc2 |
3496 3497 3498 |
bdev_cache_init(); chrdev_init(); } |