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fs/locks.c
58.9 KB
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/* * linux/fs/locks.c * * Provide support for fcntl()'s F_GETLK, F_SETLK, and F_SETLKW calls. * Doug Evans (dje@spiff.uucp), August 07, 1992 * * Deadlock detection added. * FIXME: one thing isn't handled yet: * - mandatory locks (requires lots of changes elsewhere) * Kelly Carmichael (kelly@[142.24.8.65]), September 17, 1994. * * Miscellaneous edits, and a total rewrite of posix_lock_file() code. * Kai Petzke (wpp@marie.physik.tu-berlin.de), 1994 * * Converted file_lock_table to a linked list from an array, which eliminates * the limits on how many active file locks are open. * Chad Page (pageone@netcom.com), November 27, 1994 * * Removed dependency on file descriptors. dup()'ed file descriptors now * get the same locks as the original file descriptors, and a close() on * any file descriptor removes ALL the locks on the file for the current * process. Since locks still depend on the process id, locks are inherited * after an exec() but not after a fork(). This agrees with POSIX, and both * BSD and SVR4 practice. * Andy Walker (andy@lysaker.kvaerner.no), February 14, 1995 * * Scrapped free list which is redundant now that we allocate locks * dynamically with kmalloc()/kfree(). * Andy Walker (andy@lysaker.kvaerner.no), February 21, 1995 * * Implemented two lock personalities - FL_FLOCK and FL_POSIX. * * FL_POSIX locks are created with calls to fcntl() and lockf() through the * fcntl() system call. They have the semantics described above. * * FL_FLOCK locks are created with calls to flock(), through the flock() * system call, which is new. Old C libraries implement flock() via fcntl() * and will continue to use the old, broken implementation. * * FL_FLOCK locks follow the 4.4 BSD flock() semantics. They are associated * with a file pointer (filp). As a result they can be shared by a parent * process and its children after a fork(). They are removed when the last * file descriptor referring to the file pointer is closed (unless explicitly * unlocked). * * FL_FLOCK locks never deadlock, an existing lock is always removed before * upgrading from shared to exclusive (or vice versa). When this happens * any processes blocked by the current lock are woken up and allowed to * run before the new lock is applied. * Andy Walker (andy@lysaker.kvaerner.no), June 09, 1995 * * Removed some race conditions in flock_lock_file(), marked other possible * races. Just grep for FIXME to see them. * Dmitry Gorodchanin (pgmdsg@ibi.com), February 09, 1996. * * Addressed Dmitry's concerns. Deadlock checking no longer recursive. * Lock allocation changed to GFP_ATOMIC as we can't afford to sleep * once we've checked for blocking and deadlocking. * Andy Walker (andy@lysaker.kvaerner.no), April 03, 1996. * * Initial implementation of mandatory locks. SunOS turned out to be * a rotten model, so I implemented the "obvious" semantics. |
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* See 'Documentation/filesystems/mandatory-locking.txt' for details. |
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* Andy Walker (andy@lysaker.kvaerner.no), April 06, 1996. * * Don't allow mandatory locks on mmap()'ed files. Added simple functions to * check if a file has mandatory locks, used by mmap(), open() and creat() to * see if system call should be rejected. Ref. HP-UX/SunOS/Solaris Reference * Manual, Section 2. * Andy Walker (andy@lysaker.kvaerner.no), April 09, 1996. * * Tidied up block list handling. Added '/proc/locks' interface. * Andy Walker (andy@lysaker.kvaerner.no), April 24, 1996. * * Fixed deadlock condition for pathological code that mixes calls to * flock() and fcntl(). * Andy Walker (andy@lysaker.kvaerner.no), April 29, 1996. * * Allow only one type of locking scheme (FL_POSIX or FL_FLOCK) to be in use * for a given file at a time. Changed the CONFIG_LOCK_MANDATORY scheme to * guarantee sensible behaviour in the case where file system modules might * be compiled with different options than the kernel itself. * Andy Walker (andy@lysaker.kvaerner.no), May 15, 1996. * * Added a couple of missing wake_up() calls. Thanks to Thomas Meckel * (Thomas.Meckel@mni.fh-giessen.de) for spotting this. * Andy Walker (andy@lysaker.kvaerner.no), May 15, 1996. * * Changed FL_POSIX locks to use the block list in the same way as FL_FLOCK * locks. Changed process synchronisation to avoid dereferencing locks that * have already been freed. * Andy Walker (andy@lysaker.kvaerner.no), Sep 21, 1996. * * Made the block list a circular list to minimise searching in the list. * Andy Walker (andy@lysaker.kvaerner.no), Sep 25, 1996. * * Made mandatory locking a mount option. Default is not to allow mandatory * locking. * Andy Walker (andy@lysaker.kvaerner.no), Oct 04, 1996. * * Some adaptations for NFS support. * Olaf Kirch (okir@monad.swb.de), Dec 1996, * * Fixed /proc/locks interface so that we can't overrun the buffer we are handed. * Andy Walker (andy@lysaker.kvaerner.no), May 12, 1997. * * Use slab allocator instead of kmalloc/kfree. * Use generic list implementation from <linux/list.h>. * Sped up posix_locks_deadlock by only considering blocked locks. * Matthew Wilcox <willy@debian.org>, March, 2000. * * Leases and LOCK_MAND * Matthew Wilcox <willy@debian.org>, June, 2000. * Stephen Rothwell <sfr@canb.auug.org.au>, June, 2000. */ #include <linux/capability.h> #include <linux/file.h> |
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#include <linux/fdtable.h> |
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#include <linux/fs.h> #include <linux/init.h> #include <linux/module.h> #include <linux/security.h> #include <linux/slab.h> |
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#include <linux/syscalls.h> #include <linux/time.h> |
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#include <linux/rcupdate.h> |
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#include <linux/pid_namespace.h> |
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#include <asm/uaccess.h> #define IS_POSIX(fl) (fl->fl_flags & FL_POSIX) #define IS_FLOCK(fl) (fl->fl_flags & FL_FLOCK) #define IS_LEASE(fl) (fl->fl_flags & FL_LEASE) |
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static bool lease_breaking(struct file_lock *fl) { |
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return fl->fl_flags & (FL_UNLOCK_PENDING | FL_DOWNGRADE_PENDING); } static int target_leasetype(struct file_lock *fl) { if (fl->fl_flags & FL_UNLOCK_PENDING) return F_UNLCK; if (fl->fl_flags & FL_DOWNGRADE_PENDING) return F_RDLCK; return fl->fl_type; |
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} |
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int leases_enable = 1; int lease_break_time = 45; #define for_each_lock(inode, lockp) \ for (lockp = &inode->i_flock; *lockp != NULL; lockp = &(*lockp)->fl_next) |
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static LIST_HEAD(file_lock_list); |
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static LIST_HEAD(blocked_list); |
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static DEFINE_SPINLOCK(file_lock_lock); |
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|
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/* * Protects the two list heads above, plus the inode->i_flock list |
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*/ void lock_flocks(void) { |
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spin_lock(&file_lock_lock); |
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} EXPORT_SYMBOL_GPL(lock_flocks); void unlock_flocks(void) { |
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spin_unlock(&file_lock_lock); |
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} EXPORT_SYMBOL_GPL(unlock_flocks); |
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static struct kmem_cache *filelock_cache __read_mostly; |
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static void locks_init_lock_heads(struct file_lock *fl) |
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{ |
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INIT_LIST_HEAD(&fl->fl_link); INIT_LIST_HEAD(&fl->fl_block); init_waitqueue_head(&fl->fl_wait); |
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} |
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/* Allocate an empty lock structure. */ |
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struct file_lock *locks_alloc_lock(void) |
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{ |
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struct file_lock *fl = kmem_cache_zalloc(filelock_cache, GFP_KERNEL); |
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if (fl) |
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locks_init_lock_heads(fl); |
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return fl; |
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} |
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EXPORT_SYMBOL_GPL(locks_alloc_lock); |
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void locks_release_private(struct file_lock *fl) |
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{ if (fl->fl_ops) { if (fl->fl_ops->fl_release_private) fl->fl_ops->fl_release_private(fl); fl->fl_ops = NULL; } if (fl->fl_lmops) { |
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if (fl->fl_lmops->lm_release_private) fl->fl_lmops->lm_release_private(fl); |
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fl->fl_lmops = NULL; } } |
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EXPORT_SYMBOL_GPL(locks_release_private); |
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|
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/* Free a lock which is not in use. */ |
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void locks_free_lock(struct file_lock *fl) |
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{ |
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BUG_ON(waitqueue_active(&fl->fl_wait)); BUG_ON(!list_empty(&fl->fl_block)); BUG_ON(!list_empty(&fl->fl_link)); |
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|
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locks_release_private(fl); |
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kmem_cache_free(filelock_cache, fl); } |
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EXPORT_SYMBOL(locks_free_lock); |
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void locks_init_lock(struct file_lock *fl) { |
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memset(fl, 0, sizeof(struct file_lock)); locks_init_lock_heads(fl); |
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} EXPORT_SYMBOL(locks_init_lock); |
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static void locks_copy_private(struct file_lock *new, struct file_lock *fl) { if (fl->fl_ops) { if (fl->fl_ops->fl_copy_lock) fl->fl_ops->fl_copy_lock(new, fl); new->fl_ops = fl->fl_ops; } |
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if (fl->fl_lmops) |
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new->fl_lmops = fl->fl_lmops; |
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} |
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/* * Initialize a new lock from an existing file_lock structure. */ |
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void __locks_copy_lock(struct file_lock *new, const struct file_lock *fl) |
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{ new->fl_owner = fl->fl_owner; new->fl_pid = fl->fl_pid; |
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new->fl_file = NULL; |
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new->fl_flags = fl->fl_flags; new->fl_type = fl->fl_type; new->fl_start = fl->fl_start; new->fl_end = fl->fl_end; |
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new->fl_ops = NULL; new->fl_lmops = NULL; } |
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EXPORT_SYMBOL(__locks_copy_lock); |
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void locks_copy_lock(struct file_lock *new, struct file_lock *fl) { locks_release_private(new); __locks_copy_lock(new, fl); new->fl_file = fl->fl_file; |
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new->fl_ops = fl->fl_ops; new->fl_lmops = fl->fl_lmops; |
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locks_copy_private(new, fl); |
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} EXPORT_SYMBOL(locks_copy_lock); static inline int flock_translate_cmd(int cmd) { if (cmd & LOCK_MAND) return cmd & (LOCK_MAND | LOCK_RW); switch (cmd) { case LOCK_SH: return F_RDLCK; case LOCK_EX: return F_WRLCK; case LOCK_UN: return F_UNLCK; } return -EINVAL; } /* Fill in a file_lock structure with an appropriate FLOCK lock. */ static int flock_make_lock(struct file *filp, struct file_lock **lock, unsigned int cmd) { struct file_lock *fl; int type = flock_translate_cmd(cmd); if (type < 0) return type; fl = locks_alloc_lock(); if (fl == NULL) return -ENOMEM; fl->fl_file = filp; fl->fl_pid = current->tgid; fl->fl_flags = FL_FLOCK; fl->fl_type = type; fl->fl_end = OFFSET_MAX; *lock = fl; return 0; } static int assign_type(struct file_lock *fl, int type) { switch (type) { case F_RDLCK: case F_WRLCK: case F_UNLCK: fl->fl_type = type; break; default: return -EINVAL; } return 0; } /* Verify a "struct flock" and copy it to a "struct file_lock" as a POSIX * style lock. */ static int flock_to_posix_lock(struct file *filp, struct file_lock *fl, struct flock *l) { off_t start, end; switch (l->l_whence) { |
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case SEEK_SET: |
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start = 0; break; |
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case SEEK_CUR: |
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start = filp->f_pos; break; |
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case SEEK_END: |
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start = i_size_read(filp->f_path.dentry->d_inode); |
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break; default: return -EINVAL; } /* POSIX-1996 leaves the case l->l_len < 0 undefined; POSIX-2001 defines it. */ start += l->l_start; |
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if (start < 0) return -EINVAL; fl->fl_end = OFFSET_MAX; if (l->l_len > 0) { end = start + l->l_len - 1; fl->fl_end = end; } else if (l->l_len < 0) { |
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end = start - 1; |
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fl->fl_end = end; |
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start += l->l_len; |
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if (start < 0) return -EINVAL; |
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} |
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fl->fl_start = start; /* we record the absolute position */ |
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if (fl->fl_end < fl->fl_start) return -EOVERFLOW; |
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fl->fl_owner = current->files; fl->fl_pid = current->tgid; fl->fl_file = filp; fl->fl_flags = FL_POSIX; fl->fl_ops = NULL; fl->fl_lmops = NULL; return assign_type(fl, l->l_type); } #if BITS_PER_LONG == 32 static int flock64_to_posix_lock(struct file *filp, struct file_lock *fl, struct flock64 *l) { loff_t start; switch (l->l_whence) { |
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case SEEK_SET: |
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start = 0; break; |
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case SEEK_CUR: |
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start = filp->f_pos; break; |
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case SEEK_END: |
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start = i_size_read(filp->f_path.dentry->d_inode); |
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break; default: return -EINVAL; } |
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start += l->l_start; if (start < 0) |
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return -EINVAL; |
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fl->fl_end = OFFSET_MAX; if (l->l_len > 0) { fl->fl_end = start + l->l_len - 1; } else if (l->l_len < 0) { fl->fl_end = start - 1; start += l->l_len; if (start < 0) return -EINVAL; } |
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fl->fl_start = start; /* we record the absolute position */ |
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if (fl->fl_end < fl->fl_start) return -EOVERFLOW; |
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fl->fl_owner = current->files; fl->fl_pid = current->tgid; fl->fl_file = filp; fl->fl_flags = FL_POSIX; fl->fl_ops = NULL; fl->fl_lmops = NULL; |
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return assign_type(fl, l->l_type); |
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} #endif /* default lease lock manager operations */ static void lease_break_callback(struct file_lock *fl) { kill_fasync(&fl->fl_fasync, SIGIO, POLL_MSG); } static void lease_release_private_callback(struct file_lock *fl) { if (!fl->fl_file) return; f_delown(fl->fl_file); fl->fl_file->f_owner.signum = 0; } |
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static const struct lock_manager_operations lease_manager_ops = { |
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.lm_break = lease_break_callback, .lm_release_private = lease_release_private_callback, .lm_change = lease_modify, |
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}; /* * Initialize a lease, use the default lock manager operations */ static int lease_init(struct file *filp, int type, struct file_lock *fl) { |
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if (assign_type(fl, type) != 0) return -EINVAL; |
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fl->fl_owner = current->files; fl->fl_pid = current->tgid; fl->fl_file = filp; fl->fl_flags = FL_LEASE; |
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fl->fl_start = 0; fl->fl_end = OFFSET_MAX; fl->fl_ops = NULL; fl->fl_lmops = &lease_manager_ops; return 0; } /* Allocate a file_lock initialised to this type of lease */ |
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static struct file_lock *lease_alloc(struct file *filp, int type) |
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{ struct file_lock *fl = locks_alloc_lock(); |
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int error = -ENOMEM; |
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if (fl == NULL) |
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return ERR_PTR(error); |
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error = lease_init(filp, type, fl); |
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if (error) { locks_free_lock(fl); |
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return ERR_PTR(error); |
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} |
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return fl; |
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} /* Check if two locks overlap each other. */ static inline int locks_overlap(struct file_lock *fl1, struct file_lock *fl2) { return ((fl1->fl_end >= fl2->fl_start) && (fl2->fl_end >= fl1->fl_start)); } /* * Check whether two locks have the same owner. */ |
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static int posix_same_owner(struct file_lock *fl1, struct file_lock *fl2) |
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{ |
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if (fl1->fl_lmops && fl1->fl_lmops->lm_compare_owner) |
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return fl2->fl_lmops == fl1->fl_lmops && |
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fl1->fl_lmops->lm_compare_owner(fl1, fl2); |
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return fl1->fl_owner == fl2->fl_owner; } /* Remove waiter from blocker's block list. * When blocker ends up pointing to itself then the list is empty. */ |
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static void __locks_delete_block(struct file_lock *waiter) |
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{ list_del_init(&waiter->fl_block); list_del_init(&waiter->fl_link); waiter->fl_next = NULL; } /* */ static void locks_delete_block(struct file_lock *waiter) { |
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lock_flocks(); |
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__locks_delete_block(waiter); |
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unlock_flocks(); |
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} /* Insert waiter into blocker's block list. * We use a circular list so that processes can be easily woken up in * the order they blocked. The documentation doesn't require this but * it seems like the reasonable thing to do. */ static void locks_insert_block(struct file_lock *blocker, struct file_lock *waiter) { |
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BUG_ON(!list_empty(&waiter->fl_block)); |
1da177e4c Linux-2.6.12-rc2 |
518 519 520 521 522 523 524 525 526 527 528 529 530 |
list_add_tail(&waiter->fl_block, &blocker->fl_block); waiter->fl_next = blocker; if (IS_POSIX(blocker)) list_add(&waiter->fl_link, &blocked_list); } /* Wake up processes blocked waiting for blocker. * If told to wait then schedule the processes until the block list * is empty, otherwise empty the block list ourselves. */ static void locks_wake_up_blocks(struct file_lock *blocker) { while (!list_empty(&blocker->fl_block)) { |
f0c1cd0ea Use list_first_en... |
531 532 533 |
struct file_lock *waiter; waiter = list_first_entry(&blocker->fl_block, |
1da177e4c Linux-2.6.12-rc2 |
534 535 |
struct file_lock, fl_block); __locks_delete_block(waiter); |
8fb47a4fb locks: rename loc... |
536 537 |
if (waiter->fl_lmops && waiter->fl_lmops->lm_notify) waiter->fl_lmops->lm_notify(waiter); |
1da177e4c Linux-2.6.12-rc2 |
538 539 540 541 542 543 544 545 546 547 548 |
else wake_up(&waiter->fl_wait); } } /* Insert file lock fl into an inode's lock list at the position indicated * by pos. At the same time add the lock to the global file lock list. */ static void locks_insert_lock(struct file_lock **pos, struct file_lock *fl) { list_add(&fl->fl_link, &file_lock_list); |
ab1f16116 pid-namespaces-vs... |
549 |
fl->fl_nspid = get_pid(task_tgid(current)); |
1da177e4c Linux-2.6.12-rc2 |
550 551 552 |
/* insert into file's list */ fl->fl_next = *pos; *pos = fl; |
1da177e4c Linux-2.6.12-rc2 |
553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 |
} /* * Delete a lock and then free it. * Wake up processes that are blocked waiting for this lock, * notify the FS that the lock has been cleared and * finally free the lock. */ static void locks_delete_lock(struct file_lock **thisfl_p) { struct file_lock *fl = *thisfl_p; *thisfl_p = fl->fl_next; fl->fl_next = NULL; list_del_init(&fl->fl_link); fasync_helper(0, fl->fl_file, 0, &fl->fl_fasync); if (fl->fl_fasync != NULL) { printk(KERN_ERR "locks_delete_lock: fasync == %p ", fl->fl_fasync); fl->fl_fasync = NULL; } |
ab1f16116 pid-namespaces-vs... |
575 576 577 578 |
if (fl->fl_nspid) { put_pid(fl->fl_nspid); fl->fl_nspid = NULL; } |
1da177e4c Linux-2.6.12-rc2 |
579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 |
locks_wake_up_blocks(fl); locks_free_lock(fl); } /* Determine if lock sys_fl blocks lock caller_fl. Common functionality * checks for shared/exclusive status of overlapping locks. */ static int locks_conflict(struct file_lock *caller_fl, struct file_lock *sys_fl) { if (sys_fl->fl_type == F_WRLCK) return 1; if (caller_fl->fl_type == F_WRLCK) return 1; return 0; } /* Determine if lock sys_fl blocks lock caller_fl. POSIX specific * checking before calling the locks_conflict(). */ static int posix_locks_conflict(struct file_lock *caller_fl, struct file_lock *sys_fl) { /* POSIX locks owned by the same process do not conflict with * each other. */ if (!IS_POSIX(sys_fl) || posix_same_owner(caller_fl, sys_fl)) return (0); /* Check whether they overlap */ if (!locks_overlap(caller_fl, sys_fl)) return 0; return (locks_conflict(caller_fl, sys_fl)); } /* Determine if lock sys_fl blocks lock caller_fl. FLOCK specific * checking before calling the locks_conflict(). */ static int flock_locks_conflict(struct file_lock *caller_fl, struct file_lock *sys_fl) { /* FLOCK locks referring to the same filp do not conflict with * each other. */ if (!IS_FLOCK(sys_fl) || (caller_fl->fl_file == sys_fl->fl_file)) return (0); if ((caller_fl->fl_type & LOCK_MAND) || (sys_fl->fl_type & LOCK_MAND)) return 0; return (locks_conflict(caller_fl, sys_fl)); } |
6d34ac199 locks: make posix... |
628 |
void |
9d6a8c5c2 locks: give posix... |
629 |
posix_test_lock(struct file *filp, struct file_lock *fl) |
1da177e4c Linux-2.6.12-rc2 |
630 631 |
{ struct file_lock *cfl; |
b89f43213 fs/locks.c: prepa... |
632 |
lock_flocks(); |
0f7fc9e4d [PATCH] VFS: chan... |
633 |
for (cfl = filp->f_path.dentry->d_inode->i_flock; cfl; cfl = cfl->fl_next) { |
1da177e4c Linux-2.6.12-rc2 |
634 635 |
if (!IS_POSIX(cfl)) continue; |
b842e240f locks: reverse or... |
636 |
if (posix_locks_conflict(fl, cfl)) |
1da177e4c Linux-2.6.12-rc2 |
637 638 |
break; } |
ab1f16116 pid-namespaces-vs... |
639 |
if (cfl) { |
9d6a8c5c2 locks: give posix... |
640 |
__locks_copy_lock(fl, cfl); |
ab1f16116 pid-namespaces-vs... |
641 |
if (cfl->fl_nspid) |
6c5f3e7b4 Pidns: make full ... |
642 |
fl->fl_pid = pid_vnr(cfl->fl_nspid); |
ab1f16116 pid-namespaces-vs... |
643 |
} else |
129a84de2 locks: fix F_GETL... |
644 |
fl->fl_type = F_UNLCK; |
b89f43213 fs/locks.c: prepa... |
645 |
unlock_flocks(); |
6d34ac199 locks: make posix... |
646 |
return; |
1da177e4c Linux-2.6.12-rc2 |
647 |
} |
1da177e4c Linux-2.6.12-rc2 |
648 |
EXPORT_SYMBOL(posix_test_lock); |
b533184fc locks: clarify po... |
649 650 651 652 653 |
/* * Deadlock detection: * * We attempt to detect deadlocks that are due purely to posix file * locks. |
1da177e4c Linux-2.6.12-rc2 |
654 |
* |
b533184fc locks: clarify po... |
655 656 657 658 659 660 661 |
* We assume that a task can be waiting for at most one lock at a time. * So for any acquired lock, the process holding that lock may be * waiting on at most one other lock. That lock in turns may be held by * someone waiting for at most one other lock. Given a requested lock * caller_fl which is about to wait for a conflicting lock block_fl, we * follow this chain of waiters to ensure we are not about to create a * cycle. |
1da177e4c Linux-2.6.12-rc2 |
662 |
* |
b533184fc locks: clarify po... |
663 664 665 |
* Since we do this before we ever put a process to sleep on a lock, we * are ensured that there is never a cycle; that is what guarantees that * the while() loop in posix_locks_deadlock() eventually completes. |
97855b49b locks: fix possib... |
666 |
* |
b533184fc locks: clarify po... |
667 668 669 670 671 |
* Note: the above assumption may not be true when handling lock * requests from a broken NFS client. It may also fail in the presence * of tasks (such as posix threads) sharing the same open file table. * * To handle those cases, we just bail out after a few iterations. |
1da177e4c Linux-2.6.12-rc2 |
672 |
*/ |
97855b49b locks: fix possib... |
673 674 |
#define MAX_DEADLK_ITERATIONS 10 |
b533184fc locks: clarify po... |
675 676 677 678 679 680 681 682 683 684 685 |
/* Find a lock that the owner of the given block_fl is blocking on. */ static struct file_lock *what_owner_is_waiting_for(struct file_lock *block_fl) { struct file_lock *fl; list_for_each_entry(fl, &blocked_list, fl_link) { if (posix_same_owner(fl, block_fl)) return fl->fl_next; } return NULL; } |
b0904e147 [PATCH] fs/locks.... |
686 |
static int posix_locks_deadlock(struct file_lock *caller_fl, |
1da177e4c Linux-2.6.12-rc2 |
687 688 |
struct file_lock *block_fl) { |
97855b49b locks: fix possib... |
689 |
int i = 0; |
1da177e4c Linux-2.6.12-rc2 |
690 |
|
b533184fc locks: clarify po... |
691 692 693 694 695 |
while ((block_fl = what_owner_is_waiting_for(block_fl))) { if (i++ > MAX_DEADLK_ITERATIONS) return 0; if (posix_same_owner(caller_fl, block_fl)) return 1; |
1da177e4c Linux-2.6.12-rc2 |
696 697 698 |
} return 0; } |
1da177e4c Linux-2.6.12-rc2 |
699 |
/* Try to create a FLOCK lock on filp. We always insert new FLOCK locks |
02888f41e locks: fix flock_... |
700 |
* after any leases, but before any posix locks. |
f475ae957 VFS: Allow caller... |
701 702 703 704 |
* * Note that if called with an FL_EXISTS argument, the caller may determine * whether or not a lock was successfully freed by testing the return * value for -ENOENT. |
1da177e4c Linux-2.6.12-rc2 |
705 |
*/ |
993dfa877 [PATCH] fs/locks.... |
706 |
static int flock_lock_file(struct file *filp, struct file_lock *request) |
1da177e4c Linux-2.6.12-rc2 |
707 |
{ |
993dfa877 [PATCH] fs/locks.... |
708 |
struct file_lock *new_fl = NULL; |
1da177e4c Linux-2.6.12-rc2 |
709 |
struct file_lock **before; |
0f7fc9e4d [PATCH] VFS: chan... |
710 |
struct inode * inode = filp->f_path.dentry->d_inode; |
1da177e4c Linux-2.6.12-rc2 |
711 712 |
int error = 0; int found = 0; |
b89f43213 fs/locks.c: prepa... |
713 |
if (!(request->fl_flags & FL_ACCESS) && (request->fl_type != F_UNLCK)) { |
84d535ade Memory shortage c... |
714 |
new_fl = locks_alloc_lock(); |
b89f43213 fs/locks.c: prepa... |
715 716 |
if (!new_fl) return -ENOMEM; |
84d535ade Memory shortage c... |
717 |
} |
b89f43213 fs/locks.c: prepa... |
718 719 720 |
lock_flocks(); if (request->fl_flags & FL_ACCESS) goto find_conflict; |
1da177e4c Linux-2.6.12-rc2 |
721 722 723 724 725 726 727 728 |
for_each_lock(inode, before) { struct file_lock *fl = *before; if (IS_POSIX(fl)) break; if (IS_LEASE(fl)) continue; if (filp != fl->fl_file) continue; |
993dfa877 [PATCH] fs/locks.... |
729 |
if (request->fl_type == fl->fl_type) |
1da177e4c Linux-2.6.12-rc2 |
730 731 732 733 734 |
goto out; found = 1; locks_delete_lock(before); break; } |
1da177e4c Linux-2.6.12-rc2 |
735 |
|
f475ae957 VFS: Allow caller... |
736 737 738 |
if (request->fl_type == F_UNLCK) { if ((request->fl_flags & FL_EXISTS) && !found) error = -ENOENT; |
993dfa877 [PATCH] fs/locks.... |
739 |
goto out; |
f475ae957 VFS: Allow caller... |
740 |
} |
1da177e4c Linux-2.6.12-rc2 |
741 742 743 744 745 |
/* * If a higher-priority process was blocked on the old file lock, * give it the opportunity to lock the file. */ |
b89f43213 fs/locks.c: prepa... |
746 747 |
if (found) { unlock_flocks(); |
def01bc53 sched: Convert th... |
748 |
cond_resched(); |
b89f43213 fs/locks.c: prepa... |
749 750 |
lock_flocks(); } |
1da177e4c Linux-2.6.12-rc2 |
751 |
|
f07f18dd6 VFS: Add support ... |
752 |
find_conflict: |
1da177e4c Linux-2.6.12-rc2 |
753 754 755 756 757 758 |
for_each_lock(inode, before) { struct file_lock *fl = *before; if (IS_POSIX(fl)) break; if (IS_LEASE(fl)) continue; |
993dfa877 [PATCH] fs/locks.... |
759 |
if (!flock_locks_conflict(request, fl)) |
1da177e4c Linux-2.6.12-rc2 |
760 761 |
continue; error = -EAGAIN; |
bde74e4bc locks: add specia... |
762 763 764 765 |
if (!(request->fl_flags & FL_SLEEP)) goto out; error = FILE_LOCK_DEFERRED; locks_insert_block(fl, request); |
1da177e4c Linux-2.6.12-rc2 |
766 767 |
goto out; } |
f07f18dd6 VFS: Add support ... |
768 769 |
if (request->fl_flags & FL_ACCESS) goto out; |
993dfa877 [PATCH] fs/locks.... |
770 |
locks_copy_lock(new_fl, request); |
0e2f6db88 Leases can be hid... |
771 |
locks_insert_lock(before, new_fl); |
993dfa877 [PATCH] fs/locks.... |
772 |
new_fl = NULL; |
9cedc194a [PATCH] Return er... |
773 |
error = 0; |
1da177e4c Linux-2.6.12-rc2 |
774 775 |
out: |
b89f43213 fs/locks.c: prepa... |
776 |
unlock_flocks(); |
993dfa877 [PATCH] fs/locks.... |
777 778 |
if (new_fl) locks_free_lock(new_fl); |
1da177e4c Linux-2.6.12-rc2 |
779 780 |
return error; } |
150b39345 locks: allow {vfs... |
781 |
static int __posix_lock_file(struct inode *inode, struct file_lock *request, struct file_lock *conflock) |
1da177e4c Linux-2.6.12-rc2 |
782 783 |
{ struct file_lock *fl; |
39005d022 [PATCH] locks: do... |
784 785 |
struct file_lock *new_fl = NULL; struct file_lock *new_fl2 = NULL; |
1da177e4c Linux-2.6.12-rc2 |
786 787 788 789 790 791 792 793 |
struct file_lock *left = NULL; struct file_lock *right = NULL; struct file_lock **before; int error, added = 0; /* * We may need two file_lock structures for this operation, * so we get them in advance to avoid races. |
39005d022 [PATCH] locks: do... |
794 795 |
* * In some cases we can be sure, that no new locks will be needed |
1da177e4c Linux-2.6.12-rc2 |
796 |
*/ |
39005d022 [PATCH] locks: do... |
797 798 799 800 801 802 |
if (!(request->fl_flags & FL_ACCESS) && (request->fl_type != F_UNLCK || request->fl_start != 0 || request->fl_end != OFFSET_MAX)) { new_fl = locks_alloc_lock(); new_fl2 = locks_alloc_lock(); } |
1da177e4c Linux-2.6.12-rc2 |
803 |
|
b89f43213 fs/locks.c: prepa... |
804 |
lock_flocks(); |
1da177e4c Linux-2.6.12-rc2 |
805 806 |
if (request->fl_type != F_UNLCK) { for_each_lock(inode, before) { |
526985b9d locks: kill redun... |
807 |
fl = *before; |
1da177e4c Linux-2.6.12-rc2 |
808 809 810 811 |
if (!IS_POSIX(fl)) continue; if (!posix_locks_conflict(request, fl)) continue; |
5842add2f [PATCH] VFS,fs/lo... |
812 |
if (conflock) |
1a747ee0c locks: don't call... |
813 |
__locks_copy_lock(conflock, fl); |
1da177e4c Linux-2.6.12-rc2 |
814 815 816 817 818 819 |
error = -EAGAIN; if (!(request->fl_flags & FL_SLEEP)) goto out; error = -EDEADLK; if (posix_locks_deadlock(request, fl)) goto out; |
bde74e4bc locks: add specia... |
820 |
error = FILE_LOCK_DEFERRED; |
1da177e4c Linux-2.6.12-rc2 |
821 822 823 824 825 826 827 828 829 |
locks_insert_block(fl, request); goto out; } } /* If we're just looking for a conflict, we're done. */ error = 0; if (request->fl_flags & FL_ACCESS) goto out; |
1da177e4c Linux-2.6.12-rc2 |
830 |
/* |
1da177e4c Linux-2.6.12-rc2 |
831 832 833 834 835 836 837 838 839 840 841 842 843 844 845 846 |
* Find the first old lock with the same owner as the new lock. */ before = &inode->i_flock; /* First skip locks owned by other processes. */ while ((fl = *before) && (!IS_POSIX(fl) || !posix_same_owner(request, fl))) { before = &fl->fl_next; } /* Process locks with this owner. */ while ((fl = *before) && posix_same_owner(request, fl)) { /* Detect adjacent or overlapping regions (if same lock type) */ if (request->fl_type == fl->fl_type) { |
449231d6d From: Olaf Kirch ... |
847 848 849 850 |
/* In all comparisons of start vs end, use * "start - 1" rather than "end + 1". If end * is OFFSET_MAX, end + 1 will become negative. */ |
1da177e4c Linux-2.6.12-rc2 |
851 852 853 854 855 |
if (fl->fl_end < request->fl_start - 1) goto next_lock; /* If the next lock in the list has entirely bigger * addresses than the new one, insert the lock here. */ |
449231d6d From: Olaf Kirch ... |
856 |
if (fl->fl_start - 1 > request->fl_end) |
1da177e4c Linux-2.6.12-rc2 |
857 858 859 860 861 862 863 864 865 866 867 868 869 870 871 872 873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 892 893 894 895 896 897 898 899 900 901 902 903 904 905 906 907 908 909 910 911 912 913 914 |
break; /* If we come here, the new and old lock are of the * same type and adjacent or overlapping. Make one * lock yielding from the lower start address of both * locks to the higher end address. */ if (fl->fl_start > request->fl_start) fl->fl_start = request->fl_start; else request->fl_start = fl->fl_start; if (fl->fl_end < request->fl_end) fl->fl_end = request->fl_end; else request->fl_end = fl->fl_end; if (added) { locks_delete_lock(before); continue; } request = fl; added = 1; } else { /* Processing for different lock types is a bit * more complex. */ if (fl->fl_end < request->fl_start) goto next_lock; if (fl->fl_start > request->fl_end) break; if (request->fl_type == F_UNLCK) added = 1; if (fl->fl_start < request->fl_start) left = fl; /* If the next lock in the list has a higher end * address than the new one, insert the new one here. */ if (fl->fl_end > request->fl_end) { right = fl; break; } if (fl->fl_start >= request->fl_start) { /* The new lock completely replaces an old * one (This may happen several times). */ if (added) { locks_delete_lock(before); continue; } /* Replace the old lock with the new one. * Wake up anybody waiting for the old one, * as the change in lock type might satisfy * their needs. */ locks_wake_up_blocks(fl); fl->fl_start = request->fl_start; fl->fl_end = request->fl_end; fl->fl_type = request->fl_type; |
47831f35b VFS: Fix __posix_... |
915 916 |
locks_release_private(fl); locks_copy_private(fl, request); |
1da177e4c Linux-2.6.12-rc2 |
917 918 919 920 921 922 923 924 925 |
request = fl; added = 1; } } /* Go on to next lock. */ next_lock: before = &fl->fl_next; } |
0d9a490ab [PATCH] locks: do... |
926 927 928 929 930 931 932 933 934 |
/* * The above code only modifies existing locks in case of * merging or replacing. If new lock(s) need to be inserted * all modifications are done bellow this, so it's safe yet to * bail out. */ error = -ENOLCK; /* "no luck" */ if (right && left == right && !new_fl2) goto out; |
1da177e4c Linux-2.6.12-rc2 |
935 936 |
error = 0; if (!added) { |
f475ae957 VFS: Allow caller... |
937 938 939 |
if (request->fl_type == F_UNLCK) { if (request->fl_flags & FL_EXISTS) error = -ENOENT; |
1da177e4c Linux-2.6.12-rc2 |
940 |
goto out; |
f475ae957 VFS: Allow caller... |
941 |
} |
0d9a490ab [PATCH] locks: do... |
942 943 944 945 946 |
if (!new_fl) { error = -ENOLCK; goto out; } |
1da177e4c Linux-2.6.12-rc2 |
947 948 949 950 951 952 953 954 955 956 957 958 959 960 961 962 963 964 965 966 967 968 |
locks_copy_lock(new_fl, request); locks_insert_lock(before, new_fl); new_fl = NULL; } if (right) { if (left == right) { /* The new lock breaks the old one in two pieces, * so we have to use the second new lock. */ left = new_fl2; new_fl2 = NULL; locks_copy_lock(left, right); locks_insert_lock(before, left); } right->fl_start = request->fl_end + 1; locks_wake_up_blocks(right); } if (left) { left->fl_end = request->fl_start - 1; locks_wake_up_blocks(left); } out: |
b89f43213 fs/locks.c: prepa... |
969 |
unlock_flocks(); |
1da177e4c Linux-2.6.12-rc2 |
970 971 972 973 974 975 976 977 978 979 980 981 982 983 |
/* * Free any unused locks. */ if (new_fl) locks_free_lock(new_fl); if (new_fl2) locks_free_lock(new_fl2); return error; } /** * posix_lock_file - Apply a POSIX-style lock to a file * @filp: The file to apply the lock to * @fl: The lock to be applied |
150b39345 locks: allow {vfs... |
984 |
* @conflock: Place to return a copy of the conflicting lock, if found. |
1da177e4c Linux-2.6.12-rc2 |
985 986 987 988 |
* * Add a POSIX style lock to a file. * We merge adjacent & overlapping locks whenever possible. * POSIX locks are sorted by owner task, then by starting address |
f475ae957 VFS: Allow caller... |
989 990 991 992 |
* * Note that if called with an FL_EXISTS argument, the caller may determine * whether or not a lock was successfully freed by testing the return * value for -ENOENT. |
1da177e4c Linux-2.6.12-rc2 |
993 |
*/ |
150b39345 locks: allow {vfs... |
994 |
int posix_lock_file(struct file *filp, struct file_lock *fl, |
5842add2f [PATCH] VFS,fs/lo... |
995 996 |
struct file_lock *conflock) { |
150b39345 locks: allow {vfs... |
997 |
return __posix_lock_file(filp->f_path.dentry->d_inode, fl, conflock); |
1da177e4c Linux-2.6.12-rc2 |
998 |
} |
150b39345 locks: allow {vfs... |
999 |
EXPORT_SYMBOL(posix_lock_file); |
1da177e4c Linux-2.6.12-rc2 |
1000 1001 1002 1003 1004 1005 1006 1007 1008 1009 1010 1011 1012 1013 1014 |
/** * posix_lock_file_wait - Apply a POSIX-style lock to a file * @filp: The file to apply the lock to * @fl: The lock to be applied * * Add a POSIX style lock to a file. * We merge adjacent & overlapping locks whenever possible. * POSIX locks are sorted by owner task, then by starting address */ int posix_lock_file_wait(struct file *filp, struct file_lock *fl) { int error; might_sleep (); for (;;) { |
150b39345 locks: allow {vfs... |
1015 |
error = posix_lock_file(filp, fl, NULL); |
bde74e4bc locks: add specia... |
1016 |
if (error != FILE_LOCK_DEFERRED) |
1da177e4c Linux-2.6.12-rc2 |
1017 1018 1019 1020 1021 1022 1023 1024 1025 1026 1027 1028 1029 1030 1031 1032 1033 1034 1035 1036 1037 1038 1039 1040 1041 1042 1043 |
break; error = wait_event_interruptible(fl->fl_wait, !fl->fl_next); if (!error) continue; locks_delete_block(fl); break; } return error; } EXPORT_SYMBOL(posix_lock_file_wait); /** * locks_mandatory_locked - Check for an active lock * @inode: the file to check * * Searches the inode's list of locks to find any POSIX locks which conflict. * This function is called from locks_verify_locked() only. */ int locks_mandatory_locked(struct inode *inode) { fl_owner_t owner = current->files; struct file_lock *fl; /* * Search the lock list for this inode for any POSIX locks. */ |
b89f43213 fs/locks.c: prepa... |
1044 |
lock_flocks(); |
1da177e4c Linux-2.6.12-rc2 |
1045 1046 1047 1048 1049 1050 |
for (fl = inode->i_flock; fl != NULL; fl = fl->fl_next) { if (!IS_POSIX(fl)) continue; if (fl->fl_owner != owner) break; } |
b89f43213 fs/locks.c: prepa... |
1051 |
unlock_flocks(); |
1da177e4c Linux-2.6.12-rc2 |
1052 1053 1054 1055 1056 1057 1058 1059 1060 1061 1062 1063 1064 1065 1066 1067 1068 1069 1070 1071 1072 1073 1074 1075 1076 1077 1078 1079 1080 1081 1082 1083 1084 1085 1086 |
return fl ? -EAGAIN : 0; } /** * locks_mandatory_area - Check for a conflicting lock * @read_write: %FLOCK_VERIFY_WRITE for exclusive access, %FLOCK_VERIFY_READ * for shared * @inode: the file to check * @filp: how the file was opened (if it was) * @offset: start of area to check * @count: length of area to check * * Searches the inode's list of locks to find any POSIX locks which conflict. * This function is called from rw_verify_area() and * locks_verify_truncate(). */ int locks_mandatory_area(int read_write, struct inode *inode, struct file *filp, loff_t offset, size_t count) { struct file_lock fl; int error; locks_init_lock(&fl); fl.fl_owner = current->files; fl.fl_pid = current->tgid; fl.fl_file = filp; fl.fl_flags = FL_POSIX | FL_ACCESS; if (filp && !(filp->f_flags & O_NONBLOCK)) fl.fl_flags |= FL_SLEEP; fl.fl_type = (read_write == FLOCK_VERIFY_WRITE) ? F_WRLCK : F_RDLCK; fl.fl_start = offset; fl.fl_end = offset + count - 1; for (;;) { |
150b39345 locks: allow {vfs... |
1087 |
error = __posix_lock_file(inode, &fl, NULL); |
bde74e4bc locks: add specia... |
1088 |
if (error != FILE_LOCK_DEFERRED) |
1da177e4c Linux-2.6.12-rc2 |
1089 1090 1091 1092 1093 1094 1095 |
break; error = wait_event_interruptible(fl.fl_wait, !fl.fl_next); if (!error) { /* * If we've been sleeping someone might have * changed the permissions behind our back. */ |
a16877ca9 Cleanup macros fo... |
1096 |
if (__mandatory_lock(inode)) |
1da177e4c Linux-2.6.12-rc2 |
1097 1098 1099 1100 1101 1102 1103 1104 1105 1106 1107 |
continue; } locks_delete_block(&fl); break; } return error; } EXPORT_SYMBOL(locks_mandatory_area); |
778fc546f locks: fix tracki... |
1108 1109 1110 1111 1112 1113 1114 1115 1116 1117 |
static void lease_clear_pending(struct file_lock *fl, int arg) { switch (arg) { case F_UNLCK: fl->fl_flags &= ~FL_UNLOCK_PENDING; /* fall through: */ case F_RDLCK: fl->fl_flags &= ~FL_DOWNGRADE_PENDING; } } |
1da177e4c Linux-2.6.12-rc2 |
1118 1119 1120 1121 1122 1123 1124 1125 |
/* We already had a lease on this file; just change its type */ int lease_modify(struct file_lock **before, int arg) { struct file_lock *fl = *before; int error = assign_type(fl, arg); if (error) return error; |
778fc546f locks: fix tracki... |
1126 |
lease_clear_pending(fl, arg); |
1da177e4c Linux-2.6.12-rc2 |
1127 1128 1129 1130 1131 1132 1133 |
locks_wake_up_blocks(fl); if (arg == F_UNLCK) locks_delete_lock(before); return 0; } EXPORT_SYMBOL(lease_modify); |
778fc546f locks: fix tracki... |
1134 1135 1136 1137 1138 1139 1140 |
static bool past_time(unsigned long then) { if (!then) /* 0 is a special value meaning "this never expires": */ return false; return time_after(jiffies, then); } |
1da177e4c Linux-2.6.12-rc2 |
1141 1142 1143 1144 1145 1146 |
static void time_out_leases(struct inode *inode) { struct file_lock **before; struct file_lock *fl; before = &inode->i_flock; |
ab83fa4b4 locks: minor leas... |
1147 |
while ((fl = *before) && IS_LEASE(fl) && lease_breaking(fl)) { |
778fc546f locks: fix tracki... |
1148 1149 1150 1151 |
if (past_time(fl->fl_downgrade_time)) lease_modify(before, F_RDLCK); if (past_time(fl->fl_break_time)) lease_modify(before, F_UNLCK); |
1da177e4c Linux-2.6.12-rc2 |
1152 1153 1154 1155 1156 1157 1158 1159 1160 1161 |
if (fl == *before) /* lease_modify may have freed fl */ before = &fl->fl_next; } } /** * __break_lease - revoke all outstanding leases on file * @inode: the inode of the file to return * @mode: the open mode (read or write) * |
87250dd26 leases: minor bre... |
1162 1163 1164 |
* break_lease (inlined for speed) has checked there already is at least * some kind of lock (maybe a lease) on this file. Leases are broken on * a call to open() or truncate(). This function can sleep unless you |
1da177e4c Linux-2.6.12-rc2 |
1165 1166 1167 1168 |
* specified %O_NONBLOCK to your open(). */ int __break_lease(struct inode *inode, unsigned int mode) { |
778fc546f locks: fix tracki... |
1169 |
int error = 0; |
1da177e4c Linux-2.6.12-rc2 |
1170 1171 |
struct file_lock *new_fl, *flock; struct file_lock *fl; |
1da177e4c Linux-2.6.12-rc2 |
1172 1173 |
unsigned long break_time; int i_have_this_lease = 0; |
8737c9305 Switch may_open()... |
1174 |
int want_write = (mode & O_ACCMODE) != O_RDONLY; |
1da177e4c Linux-2.6.12-rc2 |
1175 |
|
8737c9305 Switch may_open()... |
1176 |
new_fl = lease_alloc(NULL, want_write ? F_WRLCK : F_RDLCK); |
6d4b9e38d vfs: fix handling... |
1177 1178 |
if (IS_ERR(new_fl)) return PTR_ERR(new_fl); |
1da177e4c Linux-2.6.12-rc2 |
1179 |
|
b89f43213 fs/locks.c: prepa... |
1180 |
lock_flocks(); |
1da177e4c Linux-2.6.12-rc2 |
1181 1182 1183 1184 1185 1186 |
time_out_leases(inode); flock = inode->i_flock; if ((flock == NULL) || !IS_LEASE(flock)) goto out; |
778fc546f locks: fix tracki... |
1187 1188 |
if (!locks_conflict(flock, new_fl)) goto out; |
1da177e4c Linux-2.6.12-rc2 |
1189 1190 1191 |
for (fl = flock; fl && IS_LEASE(fl); fl = fl->fl_next) if (fl->fl_owner == current->files) i_have_this_lease = 1; |
1da177e4c Linux-2.6.12-rc2 |
1192 1193 1194 1195 1196 1197 1198 1199 |
break_time = 0; if (lease_break_time > 0) { break_time = jiffies + lease_break_time * HZ; if (break_time == 0) break_time++; /* so that 0 means no break time */ } for (fl = flock; fl && IS_LEASE(fl); fl = fl->fl_next) { |
778fc546f locks: fix tracki... |
1200 1201 1202 1203 |
if (want_write) { if (fl->fl_flags & FL_UNLOCK_PENDING) continue; fl->fl_flags |= FL_UNLOCK_PENDING; |
1da177e4c Linux-2.6.12-rc2 |
1204 |
fl->fl_break_time = break_time; |
778fc546f locks: fix tracki... |
1205 1206 1207 1208 1209 |
} else { if (lease_breaking(flock)) continue; fl->fl_flags |= FL_DOWNGRADE_PENDING; fl->fl_downgrade_time = break_time; |
1da177e4c Linux-2.6.12-rc2 |
1210 |
} |
778fc546f locks: fix tracki... |
1211 |
fl->fl_lmops->lm_break(fl); |
1da177e4c Linux-2.6.12-rc2 |
1212 1213 1214 1215 1216 1217 1218 1219 1220 1221 1222 1223 1224 1225 |
} if (i_have_this_lease || (mode & O_NONBLOCK)) { error = -EWOULDBLOCK; goto out; } restart: break_time = flock->fl_break_time; if (break_time != 0) { break_time -= jiffies; if (break_time == 0) break_time++; } |
4321e01e7 file locks: Use w... |
1226 |
locks_insert_block(flock, new_fl); |
b89f43213 fs/locks.c: prepa... |
1227 |
unlock_flocks(); |
4321e01e7 file locks: Use w... |
1228 1229 |
error = wait_event_interruptible_timeout(new_fl->fl_wait, !new_fl->fl_next, break_time); |
b89f43213 fs/locks.c: prepa... |
1230 |
lock_flocks(); |
4321e01e7 file locks: Use w... |
1231 |
__locks_delete_block(new_fl); |
1da177e4c Linux-2.6.12-rc2 |
1232 1233 1234 |
if (error >= 0) { if (error == 0) time_out_leases(inode); |
778fc546f locks: fix tracki... |
1235 1236 1237 1238 |
/* * Wait for the next conflicting lease that has not been * broken yet */ |
1da177e4c Linux-2.6.12-rc2 |
1239 1240 |
for (flock = inode->i_flock; flock && IS_LEASE(flock); flock = flock->fl_next) { |
778fc546f locks: fix tracki... |
1241 |
if (locks_conflict(new_fl, flock)) |
1da177e4c Linux-2.6.12-rc2 |
1242 1243 1244 1245 1246 1247 |
goto restart; } error = 0; } out: |
b89f43213 fs/locks.c: prepa... |
1248 |
unlock_flocks(); |
6d4b9e38d vfs: fix handling... |
1249 |
locks_free_lock(new_fl); |
1da177e4c Linux-2.6.12-rc2 |
1250 1251 1252 1253 1254 1255 |
return error; } EXPORT_SYMBOL(__break_lease); /** |
a6b91919e fs: fix kernel-do... |
1256 |
* lease_get_mtime - get the last modified time of an inode |
1da177e4c Linux-2.6.12-rc2 |
1257 1258 1259 1260 1261 |
* @inode: the inode * @time: pointer to a timespec which will contain the last modified time * * This is to force NFS clients to flush their caches for files with * exclusive leases. The justification is that if someone has an |
a6b91919e fs: fix kernel-do... |
1262 |
* exclusive lease, then they could be modifying it. |
1da177e4c Linux-2.6.12-rc2 |
1263 1264 1265 1266 1267 1268 1269 1270 1271 1272 1273 1274 1275 1276 1277 1278 1279 1280 1281 1282 1283 1284 1285 1286 1287 1288 1289 1290 1291 1292 1293 1294 1295 1296 1297 1298 1299 1300 1301 |
*/ void lease_get_mtime(struct inode *inode, struct timespec *time) { struct file_lock *flock = inode->i_flock; if (flock && IS_LEASE(flock) && (flock->fl_type & F_WRLCK)) *time = current_fs_time(inode->i_sb); else *time = inode->i_mtime; } EXPORT_SYMBOL(lease_get_mtime); /** * fcntl_getlease - Enquire what lease is currently active * @filp: the file * * The value returned by this function will be one of * (if no lease break is pending): * * %F_RDLCK to indicate a shared lease is held. * * %F_WRLCK to indicate an exclusive lease is held. * * %F_UNLCK to indicate no lease is held. * * (if a lease break is pending): * * %F_RDLCK to indicate an exclusive lease needs to be * changed to a shared lease (or removed). * * %F_UNLCK to indicate the lease needs to be removed. * * XXX: sfr & willy disagree over whether F_INPROGRESS * should be returned to userspace. */ int fcntl_getlease(struct file *filp) { struct file_lock *fl; int type = F_UNLCK; |
b89f43213 fs/locks.c: prepa... |
1302 |
lock_flocks(); |
0f7fc9e4d [PATCH] VFS: chan... |
1303 1304 |
time_out_leases(filp->f_path.dentry->d_inode); for (fl = filp->f_path.dentry->d_inode->i_flock; fl && IS_LEASE(fl); |
1da177e4c Linux-2.6.12-rc2 |
1305 1306 |
fl = fl->fl_next) { if (fl->fl_file == filp) { |
778fc546f locks: fix tracki... |
1307 |
type = target_leasetype(fl); |
1da177e4c Linux-2.6.12-rc2 |
1308 1309 1310 |
break; } } |
b89f43213 fs/locks.c: prepa... |
1311 |
unlock_flocks(); |
1da177e4c Linux-2.6.12-rc2 |
1312 1313 |
return type; } |
8335ebd94 leases: split up ... |
1314 |
int generic_add_lease(struct file *filp, long arg, struct file_lock **flp) |
1da177e4c Linux-2.6.12-rc2 |
1315 |
{ |
7eaae2828 [PATCH] coverity:... |
1316 |
struct file_lock *fl, **before, **my_before = NULL, *lease; |
0f7fc9e4d [PATCH] VFS: chan... |
1317 |
struct dentry *dentry = filp->f_path.dentry; |
1da177e4c Linux-2.6.12-rc2 |
1318 |
struct inode *inode = dentry->d_inode; |
c1f24ef4e locks: setlease c... |
1319 |
int error; |
1da177e4c Linux-2.6.12-rc2 |
1320 |
|
096657b65 locks: fix leaks ... |
1321 |
lease = *flp; |
8335ebd94 leases: split up ... |
1322 1323 |
error = -EAGAIN; if ((arg == F_RDLCK) && (atomic_read(&inode->i_writecount) > 0)) |
096657b65 locks: fix leaks ... |
1324 |
goto out; |
8335ebd94 leases: split up ... |
1325 1326 1327 |
if ((arg == F_WRLCK) && ((dentry->d_count > 1) || (atomic_read(&inode->i_count) > 1))) |
096657b65 locks: fix leaks ... |
1328 |
goto out; |
6d5e8b05c locks: share more... |
1329 |
|
1da177e4c Linux-2.6.12-rc2 |
1330 1331 1332 1333 1334 1335 1336 1337 |
/* * At this point, we know that if there is an exclusive * lease on this file, then we hold it on this filp * (otherwise our open of this file would have blocked). * And if we are trying to acquire an exclusive lease, * then the file is not open by anyone (including us) * except for this filp. */ |
c1f24ef4e locks: setlease c... |
1338 |
error = -EAGAIN; |
1da177e4c Linux-2.6.12-rc2 |
1339 1340 1341 |
for (before = &inode->i_flock; ((fl = *before) != NULL) && IS_LEASE(fl); before = &fl->fl_next) { |
c1f24ef4e locks: setlease c... |
1342 |
if (fl->fl_file == filp) { |
1da177e4c Linux-2.6.12-rc2 |
1343 |
my_before = before; |
c1f24ef4e locks: setlease c... |
1344 1345 1346 1347 1348 1349 1350 1351 1352 1353 1354 1355 1356 1357 |
continue; } /* * No exclusive leases if someone else has a lease on * this file: */ if (arg == F_WRLCK) goto out; /* * Modifying our existing lease is OK, but no getting a * new lease if someone else is opening for write: */ if (fl->fl_flags & FL_UNLOCK_PENDING) goto out; |
1da177e4c Linux-2.6.12-rc2 |
1358 |
} |
1da177e4c Linux-2.6.12-rc2 |
1359 |
if (my_before != NULL) { |
8fb47a4fb locks: rename loc... |
1360 |
error = lease->fl_lmops->lm_change(my_before, arg); |
51ee4b84f locks: let the ca... |
1361 1362 |
if (!error) *flp = *my_before; |
1da177e4c Linux-2.6.12-rc2 |
1363 1364 |
goto out; } |
1da177e4c Linux-2.6.12-rc2 |
1365 1366 1367 |
error = -EINVAL; if (!leases_enable) goto out; |
c5b1f0d92 locks/nfsd: alloc... |
1368 |
locks_insert_lock(before, lease); |
85c59580b locks: Fix potent... |
1369 |
return 0; |
1da177e4c Linux-2.6.12-rc2 |
1370 |
|
1da177e4c Linux-2.6.12-rc2 |
1371 1372 1373 |
out: return error; } |
8335ebd94 leases: split up ... |
1374 1375 1376 1377 1378 1379 1380 1381 1382 1383 1384 1385 1386 1387 1388 1389 1390 1391 1392 1393 1394 1395 1396 1397 1398 1399 1400 1401 1402 1403 1404 1405 1406 1407 1408 1409 1410 1411 1412 1413 1414 1415 1416 1417 1418 1419 1420 1421 1422 1423 1424 1425 1426 1427 1428 1429 |
int generic_delete_lease(struct file *filp, struct file_lock **flp) { struct file_lock *fl, **before; struct dentry *dentry = filp->f_path.dentry; struct inode *inode = dentry->d_inode; for (before = &inode->i_flock; ((fl = *before) != NULL) && IS_LEASE(fl); before = &fl->fl_next) { if (fl->fl_file != filp) continue; return (*flp)->fl_lmops->lm_change(before, F_UNLCK); } return -EAGAIN; } /** * generic_setlease - sets a lease on an open file * @filp: file pointer * @arg: type of lease to obtain * @flp: input - file_lock to use, output - file_lock inserted * * The (input) flp->fl_lmops->lm_break function is required * by break_lease(). * * Called with file_lock_lock held. */ int generic_setlease(struct file *filp, long arg, struct file_lock **flp) { struct dentry *dentry = filp->f_path.dentry; struct inode *inode = dentry->d_inode; int error; if ((current_fsuid() != inode->i_uid) && !capable(CAP_LEASE)) return -EACCES; if (!S_ISREG(inode->i_mode)) return -EINVAL; error = security_file_lock(filp, arg); if (error) return error; time_out_leases(inode); BUG_ON(!(*flp)->fl_lmops->lm_break); switch (arg) { case F_UNLCK: return generic_delete_lease(filp, flp); case F_RDLCK: case F_WRLCK: return generic_add_lease(filp, arg, flp); default: BUG(); } } |
0af1a4504 rename setlease t... |
1430 |
EXPORT_SYMBOL(generic_setlease); |
1da177e4c Linux-2.6.12-rc2 |
1431 |
|
b89f43213 fs/locks.c: prepa... |
1432 1433 1434 1435 1436 1437 1438 1439 1440 |
static int __vfs_setlease(struct file *filp, long arg, struct file_lock **lease) { if (filp->f_op && filp->f_op->setlease) return filp->f_op->setlease(filp, arg, lease); else return generic_setlease(filp, arg, lease); } /** |
a9933cea7 locks: rename lea... |
1441 |
* vfs_setlease - sets a lease on an open file |
1da177e4c Linux-2.6.12-rc2 |
1442 1443 1444 1445 1446 |
* @filp: file pointer * @arg: type of lease to obtain * @lease: file_lock to use * * Call this to establish a lease on the file. |
8fb47a4fb locks: rename loc... |
1447 |
* The (*lease)->fl_lmops->lm_break operation must be set; if not, |
f9ffed26d locks: provide a ... |
1448 1449 1450 1451 1452 1453 1454 1455 1456 1457 1458 |
* break_lease will oops! * * This will call the filesystem's setlease file method, if * defined. Note that there is no getlease method; instead, the * filesystem setlease method should call back to setlease() to * add a lease to the inode's lease list, where fcntl_getlease() can * find it. Since fcntl_getlease() only reports whether the current * task holds a lease, a cluster filesystem need only do this for * leases held by processes on this node. * * There is also no break_lease method; filesystems that |
c9404c9c3 Fix misspelling o... |
1459 |
* handle their own leases should break leases themselves from the |
f9ffed26d locks: provide a ... |
1460 1461 1462 1463 1464 |
* filesystem's open, create, and (on truncate) setattr methods. * * Warning: the only current setlease methods exist only to disable * leases in certain cases. More vfs changes may be required to * allow a full filesystem lease implementation. |
1da177e4c Linux-2.6.12-rc2 |
1465 |
*/ |
a9933cea7 locks: rename lea... |
1466 |
int vfs_setlease(struct file *filp, long arg, struct file_lock **lease) |
1da177e4c Linux-2.6.12-rc2 |
1467 |
{ |
1da177e4c Linux-2.6.12-rc2 |
1468 |
int error; |
b89f43213 fs/locks.c: prepa... |
1469 1470 1471 |
lock_flocks(); error = __vfs_setlease(filp, arg, lease); unlock_flocks(); |
1da177e4c Linux-2.6.12-rc2 |
1472 1473 1474 |
return error; } |
a9933cea7 locks: rename lea... |
1475 |
EXPORT_SYMBOL_GPL(vfs_setlease); |
1da177e4c Linux-2.6.12-rc2 |
1476 |
|
0ceaf6c70 locks: prevent EN... |
1477 1478 1479 1480 1481 1482 1483 1484 1485 1486 |
static int do_fcntl_delete_lease(struct file *filp) { struct file_lock fl, *flp = &fl; lease_init(filp, F_UNLCK, flp); return vfs_setlease(filp, F_UNLCK, &flp); } static int do_fcntl_add_lease(unsigned int fd, struct file *filp, long arg) |
1da177e4c Linux-2.6.12-rc2 |
1487 |
{ |
3df057ac9 locks: fix leak o... |
1488 |
struct file_lock *fl, *ret; |
f7347ce4e fasync: re-organi... |
1489 |
struct fasync_struct *new; |
1da177e4c Linux-2.6.12-rc2 |
1490 |
int error; |
c5b1f0d92 locks/nfsd: alloc... |
1491 1492 1493 |
fl = lease_alloc(filp, arg); if (IS_ERR(fl)) return PTR_ERR(fl); |
1da177e4c Linux-2.6.12-rc2 |
1494 |
|
f7347ce4e fasync: re-organi... |
1495 1496 1497 1498 1499 |
new = fasync_alloc(); if (!new) { locks_free_lock(fl); return -ENOMEM; } |
3df057ac9 locks: fix leak o... |
1500 |
ret = fl; |
b89f43213 fs/locks.c: prepa... |
1501 |
lock_flocks(); |
8896b93f4 locks: remove dea... |
1502 |
error = __vfs_setlease(filp, arg, &ret); |
51ee4b84f locks: let the ca... |
1503 1504 1505 1506 1507 |
if (error) { unlock_flocks(); locks_free_lock(fl); goto out_free_fasync; } |
3df057ac9 locks: fix leak o... |
1508 1509 |
if (ret != fl) locks_free_lock(fl); |
1da177e4c Linux-2.6.12-rc2 |
1510 |
|
f7347ce4e fasync: re-organi... |
1511 1512 1513 1514 1515 1516 |
/* * fasync_insert_entry() returns the old entry if any. * If there was no old entry, then it used 'new' and * inserted it into the fasync list. Clear new so that * we don't release it here. */ |
3df057ac9 locks: fix leak o... |
1517 |
if (!fasync_insert_entry(fd, filp, &ret->fl_fasync, new)) |
f7347ce4e fasync: re-organi... |
1518 |
new = NULL; |
8896b93f4 locks: remove dea... |
1519 |
error = __f_setown(filp, task_pid(current), PIDTYPE_PID, 0); |
b89f43213 fs/locks.c: prepa... |
1520 |
unlock_flocks(); |
51ee4b84f locks: let the ca... |
1521 1522 |
out_free_fasync: |
f7347ce4e fasync: re-organi... |
1523 1524 |
if (new) fasync_free(new); |
1da177e4c Linux-2.6.12-rc2 |
1525 1526 1527 1528 |
return error; } /** |
0ceaf6c70 locks: prevent EN... |
1529 1530 1531 1532 1533 1534 1535 1536 1537 1538 1539 1540 1541 1542 1543 1544 1545 |
* fcntl_setlease - sets a lease on an open file * @fd: open file descriptor * @filp: file pointer * @arg: type of lease to obtain * * Call this fcntl to establish a lease on the file. * Note that you also need to call %F_SETSIG to * receive a signal when the lease is broken. */ int fcntl_setlease(unsigned int fd, struct file *filp, long arg) { if (arg == F_UNLCK) return do_fcntl_delete_lease(filp); return do_fcntl_add_lease(fd, filp, arg); } /** |
1da177e4c Linux-2.6.12-rc2 |
1546 1547 1548 1549 1550 1551 1552 1553 1554 1555 1556 1557 |
* flock_lock_file_wait - Apply a FLOCK-style lock to a file * @filp: The file to apply the lock to * @fl: The lock to be applied * * Add a FLOCK style lock to a file. */ int flock_lock_file_wait(struct file *filp, struct file_lock *fl) { int error; might_sleep(); for (;;) { error = flock_lock_file(filp, fl); |
bde74e4bc locks: add specia... |
1558 |
if (error != FILE_LOCK_DEFERRED) |
1da177e4c Linux-2.6.12-rc2 |
1559 1560 1561 1562 1563 1564 1565 1566 1567 1568 1569 1570 1571 1572 1573 1574 1575 1576 1577 1578 1579 1580 1581 1582 1583 1584 1585 1586 1587 1588 1589 1590 |
break; error = wait_event_interruptible(fl->fl_wait, !fl->fl_next); if (!error) continue; locks_delete_block(fl); break; } return error; } EXPORT_SYMBOL(flock_lock_file_wait); /** * sys_flock: - flock() system call. * @fd: the file descriptor to lock. * @cmd: the type of lock to apply. * * Apply a %FL_FLOCK style lock to an open file descriptor. * The @cmd can be one of * * %LOCK_SH -- a shared lock. * * %LOCK_EX -- an exclusive lock. * * %LOCK_UN -- remove an existing lock. * * %LOCK_MAND -- a `mandatory' flock. This exists to emulate Windows Share Modes. * * %LOCK_MAND can be combined with %LOCK_READ or %LOCK_WRITE to allow other * processes read and write access respectively. */ |
002c8976e [CVE-2009-0029] S... |
1591 |
SYSCALL_DEFINE2(flock, unsigned int, fd, unsigned int, cmd) |
1da177e4c Linux-2.6.12-rc2 |
1592 1593 1594 1595 1596 1597 1598 1599 1600 1601 1602 1603 1604 1605 |
{ struct file *filp; struct file_lock *lock; int can_sleep, unlock; int error; error = -EBADF; filp = fget(fd); if (!filp) goto out; can_sleep = !(cmd & LOCK_NB); cmd &= ~LOCK_NB; unlock = (cmd == LOCK_UN); |
aeb5d7270 [PATCH] introduce... |
1606 1607 |
if (!unlock && !(cmd & LOCK_MAND) && !(filp->f_mode & (FMODE_READ|FMODE_WRITE))) |
1da177e4c Linux-2.6.12-rc2 |
1608 1609 1610 1611 1612 1613 1614 |
goto out_putf; error = flock_make_lock(filp, &lock, cmd); if (error) goto out_putf; if (can_sleep) lock->fl_flags |= FL_SLEEP; |
713c0ecdb security: fix sec... |
1615 |
error = security_file_lock(filp, lock->fl_type); |
1da177e4c Linux-2.6.12-rc2 |
1616 1617 1618 1619 1620 1621 1622 1623 1624 1625 1626 |
if (error) goto out_free; if (filp->f_op && filp->f_op->flock) error = filp->f_op->flock(filp, (can_sleep) ? F_SETLKW : F_SETLK, lock); else error = flock_lock_file_wait(filp, lock); out_free: |
993dfa877 [PATCH] fs/locks.... |
1627 |
locks_free_lock(lock); |
1da177e4c Linux-2.6.12-rc2 |
1628 1629 1630 1631 1632 1633 |
out_putf: fput(filp); out: return error; } |
3ee17abd1 locks: factor out... |
1634 1635 1636 |
/** * vfs_test_lock - test file byte range lock * @filp: The file to test lock for |
6924c5549 locks: fix vfs_te... |
1637 |
* @fl: The lock to test; also used to hold result |
3ee17abd1 locks: factor out... |
1638 1639 1640 1641 1642 1643 1644 1645 1646 1647 1648 1649 |
* * Returns -ERRNO on failure. Indicates presence of conflicting lock by * setting conf->fl_type to something other than F_UNLCK. */ int vfs_test_lock(struct file *filp, struct file_lock *fl) { if (filp->f_op && filp->f_op->lock) return filp->f_op->lock(filp, F_GETLK, fl); posix_test_lock(filp, fl); return 0; } EXPORT_SYMBOL_GPL(vfs_test_lock); |
c2fa1b8a6 locks: create pos... |
1650 1651 1652 1653 1654 1655 1656 1657 1658 1659 1660 1661 1662 1663 1664 1665 1666 |
static int posix_lock_to_flock(struct flock *flock, struct file_lock *fl) { flock->l_pid = fl->fl_pid; #if BITS_PER_LONG == 32 /* * Make sure we can represent the posix lock via * legacy 32bit flock. */ if (fl->fl_start > OFFT_OFFSET_MAX) return -EOVERFLOW; if (fl->fl_end != OFFSET_MAX && fl->fl_end > OFFT_OFFSET_MAX) return -EOVERFLOW; #endif flock->l_start = fl->fl_start; flock->l_len = fl->fl_end == OFFSET_MAX ? 0 : fl->fl_end - fl->fl_start + 1; flock->l_whence = 0; |
129a84de2 locks: fix F_GETL... |
1667 |
flock->l_type = fl->fl_type; |
c2fa1b8a6 locks: create pos... |
1668 1669 1670 1671 1672 1673 1674 1675 1676 1677 1678 1679 1680 1681 |
return 0; } #if BITS_PER_LONG == 32 static void posix_lock_to_flock64(struct flock64 *flock, struct file_lock *fl) { flock->l_pid = fl->fl_pid; flock->l_start = fl->fl_start; flock->l_len = fl->fl_end == OFFSET_MAX ? 0 : fl->fl_end - fl->fl_start + 1; flock->l_whence = 0; flock->l_type = fl->fl_type; } #endif |
1da177e4c Linux-2.6.12-rc2 |
1682 1683 1684 1685 1686 |
/* Report the first existing lock that would conflict with l. * This implements the F_GETLK command of fcntl(). */ int fcntl_getlk(struct file *filp, struct flock __user *l) { |
9d6a8c5c2 locks: give posix... |
1687 |
struct file_lock file_lock; |
1da177e4c Linux-2.6.12-rc2 |
1688 1689 1690 1691 1692 1693 1694 1695 1696 1697 1698 1699 1700 |
struct flock flock; int error; error = -EFAULT; if (copy_from_user(&flock, l, sizeof(flock))) goto out; error = -EINVAL; if ((flock.l_type != F_RDLCK) && (flock.l_type != F_WRLCK)) goto out; error = flock_to_posix_lock(filp, &file_lock, &flock); if (error) goto out; |
3ee17abd1 locks: factor out... |
1701 1702 1703 |
error = vfs_test_lock(filp, &file_lock); if (error) goto out; |
1da177e4c Linux-2.6.12-rc2 |
1704 |
|
9d6a8c5c2 locks: give posix... |
1705 1706 1707 |
flock.l_type = file_lock.fl_type; if (file_lock.fl_type != F_UNLCK) { error = posix_lock_to_flock(&flock, &file_lock); |
c2fa1b8a6 locks: create pos... |
1708 |
if (error) |
1da177e4c Linux-2.6.12-rc2 |
1709 |
goto out; |
1da177e4c Linux-2.6.12-rc2 |
1710 1711 1712 1713 1714 1715 1716 |
} error = -EFAULT; if (!copy_to_user(l, &flock, sizeof(flock))) error = 0; out: return error; } |
7723ec977 locks: factor out... |
1717 1718 1719 1720 1721 |
/** * vfs_lock_file - file byte range lock * @filp: The file to apply the lock to * @cmd: type of locking operation (F_SETLK, F_GETLK, etc.) * @fl: The lock to be applied |
150b39345 locks: allow {vfs... |
1722 1723 1724 1725 1726 1727 1728 1729 |
* @conf: Place to return a copy of the conflicting lock, if found. * * A caller that doesn't care about the conflicting lock may pass NULL * as the final argument. * * If the filesystem defines a private ->lock() method, then @conf will * be left unchanged; so a caller that cares should initialize it to * some acceptable default. |
2beb6614f locks: add fl_gra... |
1730 1731 1732 1733 |
* * To avoid blocking kernel daemons, such as lockd, that need to acquire POSIX * locks, the ->lock() interface may return asynchronously, before the lock has * been granted or denied by the underlying filesystem, if (and only if) |
8fb47a4fb locks: rename loc... |
1734 |
* lm_grant is set. Callers expecting ->lock() to return asynchronously |
2beb6614f locks: add fl_gra... |
1735 1736 |
* will only use F_SETLK, not F_SETLKW; they will set FL_SLEEP if (and only if) * the request is for a blocking lock. When ->lock() does return asynchronously, |
8fb47a4fb locks: rename loc... |
1737 |
* it must return FILE_LOCK_DEFERRED, and call ->lm_grant() when the lock |
2beb6614f locks: add fl_gra... |
1738 1739 |
* request completes. * If the request is for non-blocking lock the file system should return |
bde74e4bc locks: add specia... |
1740 1741 |
* FILE_LOCK_DEFERRED then try to get the lock and call the callback routine * with the result. If the request timed out the callback routine will return a |
2beb6614f locks: add fl_gra... |
1742 1743 1744 1745 1746 |
* nonzero return code and the file system should release the lock. The file * system is also responsible to keep a corresponding posix lock when it * grants a lock so the VFS can find out which locks are locally held and do * the correct lock cleanup when required. * The underlying filesystem must not drop the kernel lock or call |
8fb47a4fb locks: rename loc... |
1747 |
* ->lm_grant() before returning to the caller with a FILE_LOCK_DEFERRED |
2beb6614f locks: add fl_gra... |
1748 |
* return code. |
7723ec977 locks: factor out... |
1749 |
*/ |
150b39345 locks: allow {vfs... |
1750 |
int vfs_lock_file(struct file *filp, unsigned int cmd, struct file_lock *fl, struct file_lock *conf) |
7723ec977 locks: factor out... |
1751 1752 1753 1754 |
{ if (filp->f_op && filp->f_op->lock) return filp->f_op->lock(filp, cmd, fl); else |
150b39345 locks: allow {vfs... |
1755 |
return posix_lock_file(filp, fl, conf); |
7723ec977 locks: factor out... |
1756 1757 |
} EXPORT_SYMBOL_GPL(vfs_lock_file); |
b648a6de0 locks: cleanup co... |
1758 1759 1760 1761 1762 1763 1764 1765 |
static int do_lock_file_wait(struct file *filp, unsigned int cmd, struct file_lock *fl) { int error; error = security_file_lock(filp, fl->fl_type); if (error) return error; |
764c76b37 locks: allow ->lo... |
1766 1767 1768 |
for (;;) { error = vfs_lock_file(filp, cmd, fl, NULL); if (error != FILE_LOCK_DEFERRED) |
b648a6de0 locks: cleanup co... |
1769 |
break; |
764c76b37 locks: allow ->lo... |
1770 1771 1772 1773 1774 1775 |
error = wait_event_interruptible(fl->fl_wait, !fl->fl_next); if (!error) continue; locks_delete_block(fl); break; |
b648a6de0 locks: cleanup co... |
1776 1777 1778 1779 |
} return error; } |
1da177e4c Linux-2.6.12-rc2 |
1780 1781 1782 |
/* Apply the lock described by l to an open file descriptor. * This implements both the F_SETLK and F_SETLKW commands of fcntl(). */ |
c293621bb [PATCH] stale POS... |
1783 1784 |
int fcntl_setlk(unsigned int fd, struct file *filp, unsigned int cmd, struct flock __user *l) |
1da177e4c Linux-2.6.12-rc2 |
1785 1786 1787 1788 |
{ struct file_lock *file_lock = locks_alloc_lock(); struct flock flock; struct inode *inode; |
0b2bac2f1 [PATCH] fix SMP o... |
1789 |
struct file *f; |
1da177e4c Linux-2.6.12-rc2 |
1790 1791 1792 1793 1794 1795 1796 1797 1798 1799 1800 |
int error; if (file_lock == NULL) return -ENOLCK; /* * This might block, so we do it before checking the inode. */ error = -EFAULT; if (copy_from_user(&flock, l, sizeof(flock))) goto out; |
0f7fc9e4d [PATCH] VFS: chan... |
1801 |
inode = filp->f_path.dentry->d_inode; |
1da177e4c Linux-2.6.12-rc2 |
1802 1803 1804 1805 |
/* Don't allow mandatory locks on files that may be memory mapped * and shared. */ |
a16877ca9 Cleanup macros fo... |
1806 |
if (mandatory_lock(inode) && mapping_writably_mapped(filp->f_mapping)) { |
1da177e4c Linux-2.6.12-rc2 |
1807 1808 1809 |
error = -EAGAIN; goto out; } |
c293621bb [PATCH] stale POS... |
1810 |
again: |
1da177e4c Linux-2.6.12-rc2 |
1811 1812 1813 1814 1815 1816 1817 1818 1819 1820 1821 1822 1823 1824 1825 1826 1827 1828 1829 1830 1831 1832 1833 |
error = flock_to_posix_lock(filp, file_lock, &flock); if (error) goto out; if (cmd == F_SETLKW) { file_lock->fl_flags |= FL_SLEEP; } error = -EBADF; switch (flock.l_type) { case F_RDLCK: if (!(filp->f_mode & FMODE_READ)) goto out; break; case F_WRLCK: if (!(filp->f_mode & FMODE_WRITE)) goto out; break; case F_UNLCK: break; default: error = -EINVAL; goto out; } |
b648a6de0 locks: cleanup co... |
1834 |
error = do_lock_file_wait(filp, cmd, file_lock); |
1da177e4c Linux-2.6.12-rc2 |
1835 |
|
c293621bb [PATCH] stale POS... |
1836 1837 1838 1839 |
/* * Attempt to detect a close/fcntl race and recover by * releasing the lock that was just acquired. */ |
0b2bac2f1 [PATCH] fix SMP o... |
1840 1841 1842 1843 1844 1845 1846 1847 1848 |
/* * we need that spin_lock here - it prevents reordering between * update of inode->i_flock and check for it done in close(). * rcu_read_lock() wouldn't do. */ spin_lock(¤t->files->file_lock); f = fcheck(fd); spin_unlock(¤t->files->file_lock); if (!error && f != filp && flock.l_type != F_UNLCK) { |
c293621bb [PATCH] stale POS... |
1849 1850 |
flock.l_type = F_UNLCK; goto again; |
1da177e4c Linux-2.6.12-rc2 |
1851 |
} |
c293621bb [PATCH] stale POS... |
1852 |
out: |
1da177e4c Linux-2.6.12-rc2 |
1853 1854 1855 1856 1857 1858 1859 1860 1861 1862 |
locks_free_lock(file_lock); return error; } #if BITS_PER_LONG == 32 /* Report the first existing lock that would conflict with l. * This implements the F_GETLK command of fcntl(). */ int fcntl_getlk64(struct file *filp, struct flock64 __user *l) { |
9d6a8c5c2 locks: give posix... |
1863 |
struct file_lock file_lock; |
1da177e4c Linux-2.6.12-rc2 |
1864 1865 1866 1867 1868 1869 1870 1871 1872 1873 1874 1875 1876 |
struct flock64 flock; int error; error = -EFAULT; if (copy_from_user(&flock, l, sizeof(flock))) goto out; error = -EINVAL; if ((flock.l_type != F_RDLCK) && (flock.l_type != F_WRLCK)) goto out; error = flock64_to_posix_lock(filp, &file_lock, &flock); if (error) goto out; |
3ee17abd1 locks: factor out... |
1877 1878 1879 |
error = vfs_test_lock(filp, &file_lock); if (error) goto out; |
9d6a8c5c2 locks: give posix... |
1880 1881 1882 |
flock.l_type = file_lock.fl_type; if (file_lock.fl_type != F_UNLCK) posix_lock_to_flock64(&flock, &file_lock); |
1da177e4c Linux-2.6.12-rc2 |
1883 1884 1885 1886 1887 1888 1889 1890 1891 1892 1893 |
error = -EFAULT; if (!copy_to_user(l, &flock, sizeof(flock))) error = 0; out: return error; } /* Apply the lock described by l to an open file descriptor. * This implements both the F_SETLK and F_SETLKW commands of fcntl(). */ |
c293621bb [PATCH] stale POS... |
1894 1895 |
int fcntl_setlk64(unsigned int fd, struct file *filp, unsigned int cmd, struct flock64 __user *l) |
1da177e4c Linux-2.6.12-rc2 |
1896 1897 1898 1899 |
{ struct file_lock *file_lock = locks_alloc_lock(); struct flock64 flock; struct inode *inode; |
0b2bac2f1 [PATCH] fix SMP o... |
1900 |
struct file *f; |
1da177e4c Linux-2.6.12-rc2 |
1901 1902 1903 1904 1905 1906 1907 1908 1909 1910 1911 |
int error; if (file_lock == NULL) return -ENOLCK; /* * This might block, so we do it before checking the inode. */ error = -EFAULT; if (copy_from_user(&flock, l, sizeof(flock))) goto out; |
0f7fc9e4d [PATCH] VFS: chan... |
1912 |
inode = filp->f_path.dentry->d_inode; |
1da177e4c Linux-2.6.12-rc2 |
1913 1914 1915 1916 |
/* Don't allow mandatory locks on files that may be memory mapped * and shared. */ |
a16877ca9 Cleanup macros fo... |
1917 |
if (mandatory_lock(inode) && mapping_writably_mapped(filp->f_mapping)) { |
1da177e4c Linux-2.6.12-rc2 |
1918 1919 1920 |
error = -EAGAIN; goto out; } |
c293621bb [PATCH] stale POS... |
1921 |
again: |
1da177e4c Linux-2.6.12-rc2 |
1922 1923 1924 1925 1926 1927 1928 1929 1930 1931 1932 1933 1934 1935 1936 1937 1938 1939 1940 1941 1942 1943 1944 |
error = flock64_to_posix_lock(filp, file_lock, &flock); if (error) goto out; if (cmd == F_SETLKW64) { file_lock->fl_flags |= FL_SLEEP; } error = -EBADF; switch (flock.l_type) { case F_RDLCK: if (!(filp->f_mode & FMODE_READ)) goto out; break; case F_WRLCK: if (!(filp->f_mode & FMODE_WRITE)) goto out; break; case F_UNLCK: break; default: error = -EINVAL; goto out; } |
b648a6de0 locks: cleanup co... |
1945 |
error = do_lock_file_wait(filp, cmd, file_lock); |
1da177e4c Linux-2.6.12-rc2 |
1946 |
|
c293621bb [PATCH] stale POS... |
1947 1948 1949 1950 |
/* * Attempt to detect a close/fcntl race and recover by * releasing the lock that was just acquired. */ |
0b2bac2f1 [PATCH] fix SMP o... |
1951 1952 1953 1954 |
spin_lock(¤t->files->file_lock); f = fcheck(fd); spin_unlock(¤t->files->file_lock); if (!error && f != filp && flock.l_type != F_UNLCK) { |
c293621bb [PATCH] stale POS... |
1955 1956 |
flock.l_type = F_UNLCK; goto again; |
1da177e4c Linux-2.6.12-rc2 |
1957 1958 1959 1960 1961 1962 1963 1964 1965 1966 1967 1968 1969 1970 1971 |
} out: locks_free_lock(file_lock); return error; } #endif /* BITS_PER_LONG == 32 */ /* * This function is called when the file is being removed * from the task's fd array. POSIX locks belonging to this task * are deleted at this time. */ void locks_remove_posix(struct file *filp, fl_owner_t owner) { |
ff7b86b82 [PATCH] locks: cl... |
1972 |
struct file_lock lock; |
1da177e4c Linux-2.6.12-rc2 |
1973 1974 1975 1976 1977 1978 |
/* * If there are no locks held on this file, we don't need to call * posix_lock_file(). Another process could be setting a lock on this * file at the same time, but we wouldn't remove that lock anyway. */ |
0f7fc9e4d [PATCH] VFS: chan... |
1979 |
if (!filp->f_path.dentry->d_inode->i_flock) |
1da177e4c Linux-2.6.12-rc2 |
1980 1981 1982 |
return; lock.fl_type = F_UNLCK; |
75e1fcc0b [PATCH] vfs: add ... |
1983 |
lock.fl_flags = FL_POSIX | FL_CLOSE; |
1da177e4c Linux-2.6.12-rc2 |
1984 1985 1986 1987 1988 1989 1990 |
lock.fl_start = 0; lock.fl_end = OFFSET_MAX; lock.fl_owner = owner; lock.fl_pid = current->tgid; lock.fl_file = filp; lock.fl_ops = NULL; lock.fl_lmops = NULL; |
150b39345 locks: allow {vfs... |
1991 |
vfs_lock_file(filp, F_SETLK, &lock, NULL); |
1da177e4c Linux-2.6.12-rc2 |
1992 |
|
1da177e4c Linux-2.6.12-rc2 |
1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 |
if (lock.fl_ops && lock.fl_ops->fl_release_private) lock.fl_ops->fl_release_private(&lock); } EXPORT_SYMBOL(locks_remove_posix); /* * This function is called on the last close of an open file. */ void locks_remove_flock(struct file *filp) { |
0f7fc9e4d [PATCH] VFS: chan... |
2004 |
struct inode * inode = filp->f_path.dentry->d_inode; |
1da177e4c Linux-2.6.12-rc2 |
2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 |
struct file_lock *fl; struct file_lock **before; if (!inode->i_flock) return; if (filp->f_op && filp->f_op->flock) { struct file_lock fl = { .fl_pid = current->tgid, .fl_file = filp, .fl_flags = FL_FLOCK, .fl_type = F_UNLCK, .fl_end = OFFSET_MAX, }; filp->f_op->flock(filp, F_SETLKW, &fl); |
80fec4c62 [PATCH] VFS: Ensu... |
2020 2021 |
if (fl.fl_ops && fl.fl_ops->fl_release_private) fl.fl_ops->fl_release_private(&fl); |
1da177e4c Linux-2.6.12-rc2 |
2022 |
} |
b89f43213 fs/locks.c: prepa... |
2023 |
lock_flocks(); |
1da177e4c Linux-2.6.12-rc2 |
2024 2025 2026 2027 |
before = &inode->i_flock; while ((fl = *before) != NULL) { if (fl->fl_file == filp) { |
c293621bb [PATCH] stale POS... |
2028 |
if (IS_FLOCK(fl)) { |
1da177e4c Linux-2.6.12-rc2 |
2029 2030 2031 2032 2033 2034 2035 2036 2037 2038 2039 2040 |
locks_delete_lock(before); continue; } if (IS_LEASE(fl)) { lease_modify(before, F_UNLCK); continue; } /* What? */ BUG(); } before = &fl->fl_next; } |
b89f43213 fs/locks.c: prepa... |
2041 |
unlock_flocks(); |
1da177e4c Linux-2.6.12-rc2 |
2042 2043 2044 |
} /** |
1da177e4c Linux-2.6.12-rc2 |
2045 2046 2047 2048 2049 2050 |
* posix_unblock_lock - stop waiting for a file lock * @filp: how the file was opened * @waiter: the lock which was waiting * * lockd needs to block waiting for locks. */ |
64a318ee2 NLM: Further canc... |
2051 |
int |
1da177e4c Linux-2.6.12-rc2 |
2052 2053 |
posix_unblock_lock(struct file *filp, struct file_lock *waiter) { |
64a318ee2 NLM: Further canc... |
2054 |
int status = 0; |
b89f43213 fs/locks.c: prepa... |
2055 |
lock_flocks(); |
5996a298d NLM: don't unlock... |
2056 |
if (waiter->fl_next) |
1da177e4c Linux-2.6.12-rc2 |
2057 |
__locks_delete_block(waiter); |
64a318ee2 NLM: Further canc... |
2058 2059 |
else status = -ENOENT; |
b89f43213 fs/locks.c: prepa... |
2060 |
unlock_flocks(); |
64a318ee2 NLM: Further canc... |
2061 |
return status; |
1da177e4c Linux-2.6.12-rc2 |
2062 2063 2064 |
} EXPORT_SYMBOL(posix_unblock_lock); |
9b9d2ab41 locks: add lock c... |
2065 2066 2067 2068 2069 2070 2071 2072 2073 2074 2075 2076 2077 2078 2079 |
/** * vfs_cancel_lock - file byte range unblock lock * @filp: The file to apply the unblock to * @fl: The lock to be unblocked * * Used by lock managers to cancel blocked requests */ int vfs_cancel_lock(struct file *filp, struct file_lock *fl) { if (filp->f_op && filp->f_op->lock) return filp->f_op->lock(filp, F_CANCELLK, fl); return 0; } EXPORT_SYMBOL_GPL(vfs_cancel_lock); |
7f8ada98d Rework /proc/lock... |
2080 |
#ifdef CONFIG_PROC_FS |
d8ba7a363 proc: move rest o... |
2081 |
#include <linux/proc_fs.h> |
7f8ada98d Rework /proc/lock... |
2082 2083 2084 |
#include <linux/seq_file.h> static void lock_get_status(struct seq_file *f, struct file_lock *fl, |
99dc82925 procfs: fix numbe... |
2085 |
loff_t id, char *pfx) |
1da177e4c Linux-2.6.12-rc2 |
2086 2087 |
{ struct inode *inode = NULL; |
ab1f16116 pid-namespaces-vs... |
2088 2089 2090 |
unsigned int fl_pid; if (fl->fl_nspid) |
6c5f3e7b4 Pidns: make full ... |
2091 |
fl_pid = pid_vnr(fl->fl_nspid); |
ab1f16116 pid-namespaces-vs... |
2092 2093 |
else fl_pid = fl->fl_pid; |
1da177e4c Linux-2.6.12-rc2 |
2094 2095 |
if (fl->fl_file != NULL) |
0f7fc9e4d [PATCH] VFS: chan... |
2096 |
inode = fl->fl_file->f_path.dentry->d_inode; |
1da177e4c Linux-2.6.12-rc2 |
2097 |
|
99dc82925 procfs: fix numbe... |
2098 |
seq_printf(f, "%lld:%s ", id, pfx); |
1da177e4c Linux-2.6.12-rc2 |
2099 |
if (IS_POSIX(fl)) { |
7f8ada98d Rework /proc/lock... |
2100 |
seq_printf(f, "%6s %s ", |
1da177e4c Linux-2.6.12-rc2 |
2101 2102 |
(fl->fl_flags & FL_ACCESS) ? "ACCESS" : "POSIX ", (inode == NULL) ? "*NOINODE*" : |
a16877ca9 Cleanup macros fo... |
2103 |
mandatory_lock(inode) ? "MANDATORY" : "ADVISORY "); |
1da177e4c Linux-2.6.12-rc2 |
2104 2105 |
} else if (IS_FLOCK(fl)) { if (fl->fl_type & LOCK_MAND) { |
7f8ada98d Rework /proc/lock... |
2106 |
seq_printf(f, "FLOCK MSNFS "); |
1da177e4c Linux-2.6.12-rc2 |
2107 |
} else { |
7f8ada98d Rework /proc/lock... |
2108 |
seq_printf(f, "FLOCK ADVISORY "); |
1da177e4c Linux-2.6.12-rc2 |
2109 2110 |
} } else if (IS_LEASE(fl)) { |
7f8ada98d Rework /proc/lock... |
2111 |
seq_printf(f, "LEASE "); |
ab83fa4b4 locks: minor leas... |
2112 |
if (lease_breaking(fl)) |
7f8ada98d Rework /proc/lock... |
2113 |
seq_printf(f, "BREAKING "); |
1da177e4c Linux-2.6.12-rc2 |
2114 |
else if (fl->fl_file) |
7f8ada98d Rework /proc/lock... |
2115 |
seq_printf(f, "ACTIVE "); |
1da177e4c Linux-2.6.12-rc2 |
2116 |
else |
7f8ada98d Rework /proc/lock... |
2117 |
seq_printf(f, "BREAKER "); |
1da177e4c Linux-2.6.12-rc2 |
2118 |
} else { |
7f8ada98d Rework /proc/lock... |
2119 |
seq_printf(f, "UNKNOWN UNKNOWN "); |
1da177e4c Linux-2.6.12-rc2 |
2120 2121 |
} if (fl->fl_type & LOCK_MAND) { |
7f8ada98d Rework /proc/lock... |
2122 |
seq_printf(f, "%s ", |
1da177e4c Linux-2.6.12-rc2 |
2123 2124 2125 2126 |
(fl->fl_type & LOCK_READ) ? (fl->fl_type & LOCK_WRITE) ? "RW " : "READ " : (fl->fl_type & LOCK_WRITE) ? "WRITE" : "NONE "); } else { |
7f8ada98d Rework /proc/lock... |
2127 |
seq_printf(f, "%s ", |
ab83fa4b4 locks: minor leas... |
2128 |
(lease_breaking(fl)) |
1da177e4c Linux-2.6.12-rc2 |
2129 2130 2131 2132 2133 |
? (fl->fl_type & F_UNLCK) ? "UNLCK" : "READ " : (fl->fl_type & F_WRLCK) ? "WRITE" : "READ "); } if (inode) { #ifdef WE_CAN_BREAK_LSLK_NOW |
ab1f16116 pid-namespaces-vs... |
2134 |
seq_printf(f, "%d %s:%ld ", fl_pid, |
1da177e4c Linux-2.6.12-rc2 |
2135 2136 2137 |
inode->i_sb->s_id, inode->i_ino); #else /* userspace relies on this representation of dev_t ;-( */ |
ab1f16116 pid-namespaces-vs... |
2138 |
seq_printf(f, "%d %02x:%02x:%ld ", fl_pid, |
1da177e4c Linux-2.6.12-rc2 |
2139 2140 2141 2142 |
MAJOR(inode->i_sb->s_dev), MINOR(inode->i_sb->s_dev), inode->i_ino); #endif } else { |
ab1f16116 pid-namespaces-vs... |
2143 |
seq_printf(f, "%d <none>:0 ", fl_pid); |
1da177e4c Linux-2.6.12-rc2 |
2144 2145 2146 |
} if (IS_POSIX(fl)) { if (fl->fl_end == OFFSET_MAX) |
7f8ada98d Rework /proc/lock... |
2147 2148 |
seq_printf(f, "%Ld EOF ", fl->fl_start); |
1da177e4c Linux-2.6.12-rc2 |
2149 |
else |
7f8ada98d Rework /proc/lock... |
2150 2151 |
seq_printf(f, "%Ld %Ld ", fl->fl_start, fl->fl_end); |
1da177e4c Linux-2.6.12-rc2 |
2152 |
} else { |
7f8ada98d Rework /proc/lock... |
2153 2154 |
seq_printf(f, "0 EOF "); |
1da177e4c Linux-2.6.12-rc2 |
2155 2156 |
} } |
7f8ada98d Rework /proc/lock... |
2157 |
static int locks_show(struct seq_file *f, void *v) |
1da177e4c Linux-2.6.12-rc2 |
2158 |
{ |
7f8ada98d Rework /proc/lock... |
2159 |
struct file_lock *fl, *bfl; |
1da177e4c Linux-2.6.12-rc2 |
2160 |
|
7f8ada98d Rework /proc/lock... |
2161 |
fl = list_entry(v, struct file_lock, fl_link); |
1da177e4c Linux-2.6.12-rc2 |
2162 |
|
99dc82925 procfs: fix numbe... |
2163 |
lock_get_status(f, fl, *((loff_t *)f->private), ""); |
1da177e4c Linux-2.6.12-rc2 |
2164 |
|
7f8ada98d Rework /proc/lock... |
2165 |
list_for_each_entry(bfl, &fl->fl_block, fl_block) |
99dc82925 procfs: fix numbe... |
2166 |
lock_get_status(f, bfl, *((loff_t *)f->private), " ->"); |
094f28252 fs/locks.c: use l... |
2167 |
|
7f8ada98d Rework /proc/lock... |
2168 2169 |
return 0; } |
1da177e4c Linux-2.6.12-rc2 |
2170 |
|
7f8ada98d Rework /proc/lock... |
2171 2172 |
static void *locks_start(struct seq_file *f, loff_t *pos) { |
99dc82925 procfs: fix numbe... |
2173 |
loff_t *p = f->private; |
b89f43213 fs/locks.c: prepa... |
2174 |
lock_flocks(); |
99dc82925 procfs: fix numbe... |
2175 |
*p = (*pos + 1); |
7f8ada98d Rework /proc/lock... |
2176 2177 |
return seq_list_start(&file_lock_list, *pos); } |
1da177e4c Linux-2.6.12-rc2 |
2178 |
|
7f8ada98d Rework /proc/lock... |
2179 2180 |
static void *locks_next(struct seq_file *f, void *v, loff_t *pos) { |
99dc82925 procfs: fix numbe... |
2181 2182 |
loff_t *p = f->private; ++*p; |
7f8ada98d Rework /proc/lock... |
2183 2184 |
return seq_list_next(v, &file_lock_list, pos); } |
1da177e4c Linux-2.6.12-rc2 |
2185 |
|
7f8ada98d Rework /proc/lock... |
2186 2187 |
static void locks_stop(struct seq_file *f, void *v) { |
b89f43213 fs/locks.c: prepa... |
2188 |
unlock_flocks(); |
1da177e4c Linux-2.6.12-rc2 |
2189 |
} |
d8ba7a363 proc: move rest o... |
2190 |
static const struct seq_operations locks_seq_operations = { |
7f8ada98d Rework /proc/lock... |
2191 2192 2193 2194 2195 |
.start = locks_start, .next = locks_next, .stop = locks_stop, .show = locks_show, }; |
d8ba7a363 proc: move rest o... |
2196 2197 2198 |
static int locks_open(struct inode *inode, struct file *filp) { |
99dc82925 procfs: fix numbe... |
2199 |
return seq_open_private(filp, &locks_seq_operations, sizeof(loff_t)); |
d8ba7a363 proc: move rest o... |
2200 2201 2202 2203 2204 2205 |
} static const struct file_operations proc_locks_operations = { .open = locks_open, .read = seq_read, .llseek = seq_lseek, |
99dc82925 procfs: fix numbe... |
2206 |
.release = seq_release_private, |
d8ba7a363 proc: move rest o... |
2207 2208 2209 2210 2211 2212 2213 2214 |
}; static int __init proc_locks_init(void) { proc_create("locks", 0, NULL, &proc_locks_operations); return 0; } module_init(proc_locks_init); |
7f8ada98d Rework /proc/lock... |
2215 |
#endif |
1da177e4c Linux-2.6.12-rc2 |
2216 2217 2218 2219 2220 2221 2222 2223 2224 2225 2226 2227 2228 2229 2230 2231 2232 |
/** * lock_may_read - checks that the region is free of locks * @inode: the inode that is being read * @start: the first byte to read * @len: the number of bytes to read * * Emulates Windows locking requirements. Whole-file * mandatory locks (share modes) can prohibit a read and * byte-range POSIX locks can prohibit a read if they overlap. * * N.B. this function is only ever called * from knfsd and ownership of locks is never checked. */ int lock_may_read(struct inode *inode, loff_t start, unsigned long len) { struct file_lock *fl; int result = 1; |
b89f43213 fs/locks.c: prepa... |
2233 |
lock_flocks(); |
1da177e4c Linux-2.6.12-rc2 |
2234 2235 2236 2237 2238 2239 2240 2241 2242 2243 2244 2245 2246 2247 2248 2249 |
for (fl = inode->i_flock; fl != NULL; fl = fl->fl_next) { if (IS_POSIX(fl)) { if (fl->fl_type == F_RDLCK) continue; if ((fl->fl_end < start) || (fl->fl_start > (start + len))) continue; } else if (IS_FLOCK(fl)) { if (!(fl->fl_type & LOCK_MAND)) continue; if (fl->fl_type & LOCK_READ) continue; } else continue; result = 0; break; } |
b89f43213 fs/locks.c: prepa... |
2250 |
unlock_flocks(); |
1da177e4c Linux-2.6.12-rc2 |
2251 2252 2253 2254 2255 2256 2257 2258 2259 2260 2261 2262 2263 2264 2265 2266 2267 2268 2269 2270 2271 2272 |
return result; } EXPORT_SYMBOL(lock_may_read); /** * lock_may_write - checks that the region is free of locks * @inode: the inode that is being written * @start: the first byte to write * @len: the number of bytes to write * * Emulates Windows locking requirements. Whole-file * mandatory locks (share modes) can prohibit a write and * byte-range POSIX locks can prohibit a write if they overlap. * * N.B. this function is only ever called * from knfsd and ownership of locks is never checked. */ int lock_may_write(struct inode *inode, loff_t start, unsigned long len) { struct file_lock *fl; int result = 1; |
b89f43213 fs/locks.c: prepa... |
2273 |
lock_flocks(); |
1da177e4c Linux-2.6.12-rc2 |
2274 2275 2276 2277 2278 2279 2280 2281 2282 2283 2284 2285 2286 2287 |
for (fl = inode->i_flock; fl != NULL; fl = fl->fl_next) { if (IS_POSIX(fl)) { if ((fl->fl_end < start) || (fl->fl_start > (start + len))) continue; } else if (IS_FLOCK(fl)) { if (!(fl->fl_type & LOCK_MAND)) continue; if (fl->fl_type & LOCK_WRITE) continue; } else continue; result = 0; break; } |
b89f43213 fs/locks.c: prepa... |
2288 |
unlock_flocks(); |
1da177e4c Linux-2.6.12-rc2 |
2289 2290 2291 2292 |
return result; } EXPORT_SYMBOL(lock_may_write); |
1da177e4c Linux-2.6.12-rc2 |
2293 2294 2295 |
static int __init filelock_init(void) { filelock_cache = kmem_cache_create("file_lock_cache", |
ee19cc406 fs: locks: remove... |
2296 |
sizeof(struct file_lock), 0, SLAB_PANIC, NULL); |
1da177e4c Linux-2.6.12-rc2 |
2297 2298 2299 2300 |
return 0; } core_initcall(filelock_init); |