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fs/super.c
24.8 KB
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/* * linux/fs/super.c * * Copyright (C) 1991, 1992 Linus Torvalds * * super.c contains code to handle: - mount structures * - super-block tables * - filesystem drivers list * - mount system call * - umount system call * - ustat system call * * GK 2/5/95 - Changed to support mounting the root fs via NFS * * Added kerneld support: Jacques Gelinas and Bjorn Ekwall * Added change_root: Werner Almesberger & Hans Lermen, Feb '96 * Added options to /proc/mounts: |
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* Torbjörn Lindh (torbjorn.lindh@gopta.se), April 14, 1996. |
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* Added devfs support: Richard Gooch <rgooch@atnf.csiro.au>, 13-JAN-1998 * Heavily rewritten for 'one fs - one tree' dcache architecture. AV, Mar 2000 */ |
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#include <linux/module.h> #include <linux/slab.h> |
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#include <linux/acct.h> #include <linux/blkdev.h> |
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#include <linux/mount.h> #include <linux/security.h> |
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#include <linux/writeback.h> /* for the emergency remount stuff */ #include <linux/idr.h> |
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#include <linux/mutex.h> |
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#include <linux/backing-dev.h> |
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#include "internal.h" |
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|
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LIST_HEAD(super_blocks); DEFINE_SPINLOCK(sb_lock); /** * alloc_super - create new superblock |
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* @type: filesystem type superblock should belong to |
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* * Allocates and initializes a new &struct super_block. alloc_super() * returns a pointer new superblock or %NULL if allocation had failed. */ |
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static struct super_block *alloc_super(struct file_system_type *type) |
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{ |
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struct super_block *s = kzalloc(sizeof(struct super_block), GFP_USER); |
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static const struct super_operations default_op; |
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if (s) { |
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if (security_sb_alloc(s)) { kfree(s); s = NULL; goto out; } |
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INIT_LIST_HEAD(&s->s_files); INIT_LIST_HEAD(&s->s_instances); INIT_HLIST_HEAD(&s->s_anon); INIT_LIST_HEAD(&s->s_inodes); |
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INIT_LIST_HEAD(&s->s_dentry_lru); |
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init_rwsem(&s->s_umount); |
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mutex_init(&s->s_lock); |
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lockdep_set_class(&s->s_umount, &type->s_umount_key); |
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/* * The locking rules for s_lock are up to the * filesystem. For example ext3fs has different * lock ordering than usbfs: */ lockdep_set_class(&s->s_lock, &type->s_lock_key); |
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/* * sget() can have s_umount recursion. * * When it cannot find a suitable sb, it allocates a new * one (this one), and tries again to find a suitable old * one. * * In case that succeeds, it will acquire the s_umount * lock of the old one. Since these are clearly distrinct * locks, and this object isn't exposed yet, there's no * risk of deadlocks. * * Annotate this by putting this lock in a different * subclass. */ down_write_nested(&s->s_umount, SINGLE_DEPTH_NESTING); |
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s->s_count = 1; |
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atomic_set(&s->s_active, 1); |
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mutex_init(&s->s_vfs_rename_mutex); |
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lockdep_set_class(&s->s_vfs_rename_mutex, &type->s_vfs_rename_key); |
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mutex_init(&s->s_dquot.dqio_mutex); mutex_init(&s->s_dquot.dqonoff_mutex); |
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init_rwsem(&s->s_dquot.dqptr_sem); init_waitqueue_head(&s->s_wait_unfrozen); s->s_maxbytes = MAX_NON_LFS; |
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s->s_op = &default_op; s->s_time_gran = 1000000000; } out: return s; } /** * destroy_super - frees a superblock * @s: superblock to free * * Frees a superblock. */ static inline void destroy_super(struct super_block *s) { security_sb_free(s); |
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kfree(s->s_subtype); |
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kfree(s->s_options); |
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kfree(s); } /* Superblock refcounting */ /* |
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* Drop a superblock's refcount. The caller must hold sb_lock. |
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*/ |
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void __put_super(struct super_block *sb) |
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{ |
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if (!--sb->s_count) { |
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list_del_init(&sb->s_list); |
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destroy_super(sb); |
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} |
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} /** * put_super - drop a temporary reference to superblock * @sb: superblock in question * * Drops a temporary reference, frees superblock if there's no * references left. */ |
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void put_super(struct super_block *sb) |
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{ spin_lock(&sb_lock); __put_super(sb); spin_unlock(&sb_lock); } /** |
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* deactivate_locked_super - drop an active reference to superblock |
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* @s: superblock to deactivate * |
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* Drops an active reference to superblock, converting it into a temprory * one if there is no other active references left. In that case we |
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* tell fs driver to shut it down and drop the temporary reference we * had just acquired. |
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* * Caller holds exclusive lock on superblock; that lock is released. |
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*/ |
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void deactivate_locked_super(struct super_block *s) |
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{ struct file_system_type *fs = s->s_type; |
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if (atomic_dec_and_test(&s->s_active)) { |
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fs->kill_sb(s); put_filesystem(fs); put_super(s); |
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} else { up_write(&s->s_umount); |
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} } |
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EXPORT_SYMBOL(deactivate_locked_super); |
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/** |
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* deactivate_super - drop an active reference to superblock |
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* @s: superblock to deactivate * |
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* Variant of deactivate_locked_super(), except that superblock is *not* * locked by caller. If we are going to drop the final active reference, * lock will be acquired prior to that. |
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*/ |
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void deactivate_super(struct super_block *s) |
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{ |
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if (!atomic_add_unless(&s->s_active, -1, 1)) { down_write(&s->s_umount); deactivate_locked_super(s); |
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} } |
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EXPORT_SYMBOL(deactivate_super); |
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/** |
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* grab_super - acquire an active reference * @s: reference we are trying to make active * * Tries to acquire an active reference. grab_super() is used when we * had just found a superblock in super_blocks or fs_type->fs_supers * and want to turn it into a full-blown active reference. grab_super() * is called with sb_lock held and drops it. Returns 1 in case of * success, 0 if we had failed (superblock contents was already dead or * dying when grab_super() had been called). */ |
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static int grab_super(struct super_block *s) __releases(sb_lock) |
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{ |
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if (atomic_inc_not_zero(&s->s_active)) { spin_unlock(&sb_lock); |
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return 1; } /* it's going away */ |
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s->s_count++; spin_unlock(&sb_lock); |
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/* wait for it to die */ |
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down_write(&s->s_umount); |
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up_write(&s->s_umount); put_super(s); |
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return 0; } |
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/* |
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* Superblock locking. We really ought to get rid of these two. */ void lock_super(struct super_block * sb) { get_fs_excl(); mutex_lock(&sb->s_lock); } void unlock_super(struct super_block * sb) { put_fs_excl(); mutex_unlock(&sb->s_lock); } EXPORT_SYMBOL(lock_super); EXPORT_SYMBOL(unlock_super); |
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/** * generic_shutdown_super - common helper for ->kill_sb() * @sb: superblock to kill * * generic_shutdown_super() does all fs-independent work on superblock * shutdown. Typical ->kill_sb() should pick all fs-specific objects * that need destruction out of superblock, call generic_shutdown_super() * and release aforementioned objects. Note: dentries and inodes _are_ * taken care of and do not need specific handling. |
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* * Upon calling this function, the filesystem may no longer alter or * rearrange the set of dentries belonging to this super_block, nor may it * change the attachments of dentries to inodes. |
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*/ void generic_shutdown_super(struct super_block *sb) { |
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const struct super_operations *sop = sb->s_op; |
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if (sb->s_root) { shrink_dcache_for_umount(sb); |
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sync_filesystem(sb); |
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get_fs_excl(); |
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sb->s_flags &= ~MS_ACTIVE; |
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|
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/* bad name - it should be evict_inodes() */ invalidate_inodes(sb); |
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|
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if (sop->put_super) sop->put_super(sb); /* Forget any remaining inodes */ if (invalidate_inodes(sb)) { |
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printk("VFS: Busy inodes after unmount of %s. " "Self-destruct in 5 seconds. Have a nice day... ", sb->s_id); |
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} |
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put_fs_excl(); |
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} spin_lock(&sb_lock); /* should be initialized for __put_super_and_need_restart() */ |
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list_del_init(&sb->s_instances); |
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spin_unlock(&sb_lock); up_write(&sb->s_umount); } EXPORT_SYMBOL(generic_shutdown_super); /** * sget - find or create a superblock * @type: filesystem type superblock should belong to * @test: comparison callback * @set: setup callback * @data: argument to each of them */ struct super_block *sget(struct file_system_type *type, int (*test)(struct super_block *,void *), int (*set)(struct super_block *,void *), void *data) { struct super_block *s = NULL; |
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struct super_block *old; |
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int err; retry: spin_lock(&sb_lock); |
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if (test) { list_for_each_entry(old, &type->fs_supers, s_instances) { if (!test(old, data)) continue; if (!grab_super(old)) goto retry; |
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if (s) { up_write(&s->s_umount); |
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destroy_super(s); |
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} |
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down_write(&old->s_umount); |
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return old; } |
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} if (!s) { spin_unlock(&sb_lock); |
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s = alloc_super(type); |
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if (!s) return ERR_PTR(-ENOMEM); goto retry; } err = set(s, data); if (err) { spin_unlock(&sb_lock); |
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up_write(&s->s_umount); |
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destroy_super(s); return ERR_PTR(err); } s->s_type = type; strlcpy(s->s_id, type->name, sizeof(s->s_id)); list_add_tail(&s->s_list, &super_blocks); list_add(&s->s_instances, &type->fs_supers); spin_unlock(&sb_lock); get_filesystem(type); return s; } EXPORT_SYMBOL(sget); void drop_super(struct super_block *sb) { up_read(&sb->s_umount); put_super(sb); } EXPORT_SYMBOL(drop_super); |
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/** * sync_supers - helper for periodic superblock writeback * * Call the write_super method if present on all dirty superblocks in * the system. This is for the periodic writeback used by most older * filesystems. For data integrity superblock writeback use * sync_filesystems() instead. * |
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* Note: check the dirty flag before waiting, so we don't * hold up the sync while mounting a device. (The newly * mounted device won't need syncing.) */ void sync_supers(void) { |
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struct super_block *sb, *n; |
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|
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spin_lock(&sb_lock); |
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list_for_each_entry_safe(sb, n, &super_blocks, s_list) { |
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if (list_empty(&sb->s_instances)) continue; |
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if (sb->s_op->write_super && sb->s_dirt) { |
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sb->s_count++; spin_unlock(&sb_lock); |
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|
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down_read(&sb->s_umount); |
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if (sb->s_root && sb->s_dirt) sb->s_op->write_super(sb); |
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up_read(&sb->s_umount); |
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|
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spin_lock(&sb_lock); |
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/* lock was dropped, must reset next */ list_safe_reset_next(sb, n, s_list); |
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__put_super(sb); |
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} } |
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spin_unlock(&sb_lock); } |
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/** |
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* iterate_supers - call function for all active superblocks * @f: function to call * @arg: argument to pass to it * * Scans the superblock list and calls given function, passing it * locked superblock and given argument. */ void iterate_supers(void (*f)(struct super_block *, void *), void *arg) { struct super_block *sb, *n; spin_lock(&sb_lock); list_for_each_entry_safe(sb, n, &super_blocks, s_list) { if (list_empty(&sb->s_instances)) continue; sb->s_count++; spin_unlock(&sb_lock); down_read(&sb->s_umount); if (sb->s_root) f(sb, arg); up_read(&sb->s_umount); spin_lock(&sb_lock); |
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/* lock was dropped, must reset next */ list_safe_reset_next(sb, n, s_list); |
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__put_super(sb); } spin_unlock(&sb_lock); } /** |
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* get_super - get the superblock of a device * @bdev: device to get the superblock for * * Scans the superblock list and finds the superblock of the file system * mounted on the device given. %NULL is returned if no match is found. */ |
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struct super_block *get_super(struct block_device *bdev) |
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{ |
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struct super_block *sb; |
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if (!bdev) return NULL; |
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|
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spin_lock(&sb_lock); |
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rescan: list_for_each_entry(sb, &super_blocks, s_list) { |
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if (list_empty(&sb->s_instances)) continue; |
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if (sb->s_bdev == bdev) { sb->s_count++; |
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spin_unlock(&sb_lock); |
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down_read(&sb->s_umount); |
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/* still alive? */ |
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if (sb->s_root) return sb; up_read(&sb->s_umount); |
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/* nope, got unmounted */ |
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spin_lock(&sb_lock); |
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__put_super(sb); goto rescan; |
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} } spin_unlock(&sb_lock); return NULL; } EXPORT_SYMBOL(get_super); |
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/** * get_active_super - get an active reference to the superblock of a device * @bdev: device to get the superblock for * * Scans the superblock list and finds the superblock of the file system * mounted on the device given. Returns the superblock with an active |
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* reference or %NULL if none was found. |
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*/ struct super_block *get_active_super(struct block_device *bdev) { struct super_block *sb; if (!bdev) return NULL; |
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restart: |
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spin_lock(&sb_lock); list_for_each_entry(sb, &super_blocks, s_list) { |
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if (list_empty(&sb->s_instances)) continue; |
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if (sb->s_bdev == bdev) { if (grab_super(sb)) /* drops sb_lock */ return sb; else goto restart; } |
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} spin_unlock(&sb_lock); return NULL; } |
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|
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struct super_block *user_get_super(dev_t dev) |
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{ |
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struct super_block *sb; |
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|
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spin_lock(&sb_lock); |
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rescan: list_for_each_entry(sb, &super_blocks, s_list) { |
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485 486 |
if (list_empty(&sb->s_instances)) continue; |
618f06362 [PATCH] O(1) sb l... |
487 488 |
if (sb->s_dev == dev) { sb->s_count++; |
1da177e4c Linux-2.6.12-rc2 |
489 |
spin_unlock(&sb_lock); |
618f06362 [PATCH] O(1) sb l... |
490 |
down_read(&sb->s_umount); |
df40c01a9 In get_super() an... |
491 |
/* still alive? */ |
618f06362 [PATCH] O(1) sb l... |
492 493 494 |
if (sb->s_root) return sb; up_read(&sb->s_umount); |
df40c01a9 In get_super() an... |
495 |
/* nope, got unmounted */ |
618f06362 [PATCH] O(1) sb l... |
496 |
spin_lock(&sb_lock); |
df40c01a9 In get_super() an... |
497 498 |
__put_super(sb); goto rescan; |
1da177e4c Linux-2.6.12-rc2 |
499 500 501 502 503 |
} } spin_unlock(&sb_lock); return NULL; } |
1da177e4c Linux-2.6.12-rc2 |
504 |
/** |
1da177e4c Linux-2.6.12-rc2 |
505 506 507 508 509 510 511 512 513 514 515 |
* do_remount_sb - asks filesystem to change mount options. * @sb: superblock in question * @flags: numeric part of options * @data: the rest of options * @force: whether or not to force the change * * Alters the mount options of a mounted file system. */ int do_remount_sb(struct super_block *sb, int flags, void *data, int force) { int retval; |
c79d967de quota: move remou... |
516 |
int remount_ro; |
4504230a7 freeze_bdev: grab... |
517 518 519 |
if (sb->s_frozen != SB_UNFROZEN) return -EBUSY; |
9361401eb [PATCH] BLOCK: Ma... |
520 |
#ifdef CONFIG_BLOCK |
1da177e4c Linux-2.6.12-rc2 |
521 522 |
if (!(flags & MS_RDONLY) && bdev_read_only(sb->s_bdev)) return -EACCES; |
9361401eb [PATCH] BLOCK: Ma... |
523 |
#endif |
4504230a7 freeze_bdev: grab... |
524 |
|
1da177e4c Linux-2.6.12-rc2 |
525 526 527 |
if (flags & MS_RDONLY) acct_auto_close(sb); shrink_dcache_sb(sb); |
60b0680fa vfs: Rename fsync... |
528 |
sync_filesystem(sb); |
1da177e4c Linux-2.6.12-rc2 |
529 |
|
d208bbdda fs: improve remou... |
530 |
remount_ro = (flags & MS_RDONLY) && !(sb->s_flags & MS_RDONLY); |
d208bbdda fs: improve remou... |
531 |
|
1da177e4c Linux-2.6.12-rc2 |
532 533 |
/* If we are remounting RDONLY and current sb is read/write, make sure there are no rw files opened */ |
d208bbdda fs: improve remou... |
534 |
if (remount_ro) { |
1da177e4c Linux-2.6.12-rc2 |
535 536 |
if (force) mark_files_ro(sb); |
b0895513f remove unlock_ker... |
537 |
else if (!fs_may_remount_ro(sb)) |
1da177e4c Linux-2.6.12-rc2 |
538 539 540 541 |
return -EBUSY; } if (sb->s_op->remount_fs) { |
1da177e4c Linux-2.6.12-rc2 |
542 |
retval = sb->s_op->remount_fs(sb, &flags, data); |
b0895513f remove unlock_ker... |
543 |
if (retval) |
1da177e4c Linux-2.6.12-rc2 |
544 545 546 |
return retval; } sb->s_flags = (sb->s_flags & ~MS_RMT_MASK) | (flags & MS_RMT_MASK); |
c79d967de quota: move remou... |
547 |
|
d208bbdda fs: improve remou... |
548 549 550 551 552 553 554 555 556 557 |
/* * Some filesystems modify their metadata via some other path than the * bdev buffer cache (eg. use a private mapping, or directories in * pagecache, etc). Also file data modifications go via their own * mappings. So If we try to mount readonly then copy the filesystem * from bdev, we could get stale data, so invalidate it to give a best * effort at coherency. */ if (remount_ro && sb->s_bdev) invalidate_bdev(sb->s_bdev); |
1da177e4c Linux-2.6.12-rc2 |
558 559 |
return 0; } |
a2a9537ac Get rid of pdflus... |
560 |
static void do_emergency_remount(struct work_struct *work) |
1da177e4c Linux-2.6.12-rc2 |
561 |
{ |
e7fe0585c fix do_emergency_... |
562 |
struct super_block *sb, *n; |
1da177e4c Linux-2.6.12-rc2 |
563 564 |
spin_lock(&sb_lock); |
e7fe0585c fix do_emergency_... |
565 |
list_for_each_entry_safe(sb, n, &super_blocks, s_list) { |
551de6f34 Leave superblocks... |
566 567 |
if (list_empty(&sb->s_instances)) continue; |
1da177e4c Linux-2.6.12-rc2 |
568 569 |
sb->s_count++; spin_unlock(&sb_lock); |
443b94baa Make sure that al... |
570 |
down_write(&sb->s_umount); |
1da177e4c Linux-2.6.12-rc2 |
571 572 |
if (sb->s_root && sb->s_bdev && !(sb->s_flags & MS_RDONLY)) { /* |
1da177e4c Linux-2.6.12-rc2 |
573 574 |
* What lock protects sb->s_flags?? */ |
1da177e4c Linux-2.6.12-rc2 |
575 |
do_remount_sb(sb, MS_RDONLY, NULL, 1); |
1da177e4c Linux-2.6.12-rc2 |
576 |
} |
443b94baa Make sure that al... |
577 |
up_write(&sb->s_umount); |
1da177e4c Linux-2.6.12-rc2 |
578 |
spin_lock(&sb_lock); |
57439f878 fs: fix superbloc... |
579 580 |
/* lock was dropped, must reset next */ list_safe_reset_next(sb, n, s_list); |
e7fe0585c fix do_emergency_... |
581 |
__put_super(sb); |
1da177e4c Linux-2.6.12-rc2 |
582 583 |
} spin_unlock(&sb_lock); |
a2a9537ac Get rid of pdflus... |
584 |
kfree(work); |
1da177e4c Linux-2.6.12-rc2 |
585 586 587 588 589 590 |
printk("Emergency Remount complete "); } void emergency_remount(void) { |
a2a9537ac Get rid of pdflus... |
591 592 593 594 595 596 597 |
struct work_struct *work; work = kmalloc(sizeof(*work), GFP_ATOMIC); if (work) { INIT_WORK(work, do_emergency_remount); schedule_work(work); } |
1da177e4c Linux-2.6.12-rc2 |
598 599 600 601 602 603 |
} /* * Unnamed block devices are dummy devices used by virtual * filesystems which don't use real block-devices. -- jrs */ |
ad76cbc63 [PATCH 2/2] anond... |
604 |
static DEFINE_IDA(unnamed_dev_ida); |
1da177e4c Linux-2.6.12-rc2 |
605 |
static DEFINE_SPINLOCK(unnamed_dev_lock);/* protects the above */ |
c63e09ecc Make allocation o... |
606 |
static int unnamed_dev_start = 0; /* don't bother trying below it */ |
1da177e4c Linux-2.6.12-rc2 |
607 608 609 610 611 612 613 |
int set_anon_super(struct super_block *s, void *data) { int dev; int error; retry: |
ad76cbc63 [PATCH 2/2] anond... |
614 |
if (ida_pre_get(&unnamed_dev_ida, GFP_ATOMIC) == 0) |
1da177e4c Linux-2.6.12-rc2 |
615 616 |
return -ENOMEM; spin_lock(&unnamed_dev_lock); |
c63e09ecc Make allocation o... |
617 |
error = ida_get_new_above(&unnamed_dev_ida, unnamed_dev_start, &dev); |
f21f62208 ... and the same ... |
618 619 |
if (!error) unnamed_dev_start = dev + 1; |
1da177e4c Linux-2.6.12-rc2 |
620 621 622 623 624 625 626 627 628 |
spin_unlock(&unnamed_dev_lock); if (error == -EAGAIN) /* We raced and lost with another CPU. */ goto retry; else if (error) return -EAGAIN; if ((dev & MAX_ID_MASK) == (1 << MINORBITS)) { spin_lock(&unnamed_dev_lock); |
ad76cbc63 [PATCH 2/2] anond... |
629 |
ida_remove(&unnamed_dev_ida, dev); |
f21f62208 ... and the same ... |
630 631 |
if (unnamed_dev_start > dev) unnamed_dev_start = dev; |
1da177e4c Linux-2.6.12-rc2 |
632 633 634 635 |
spin_unlock(&unnamed_dev_lock); return -EMFILE; } s->s_dev = MKDEV(0, dev & MINORMASK); |
5129a469a Catch filesystems... |
636 |
s->s_bdi = &noop_backing_dev_info; |
1da177e4c Linux-2.6.12-rc2 |
637 638 639 640 641 642 643 644 645 646 647 |
return 0; } EXPORT_SYMBOL(set_anon_super); void kill_anon_super(struct super_block *sb) { int slot = MINOR(sb->s_dev); generic_shutdown_super(sb); spin_lock(&unnamed_dev_lock); |
ad76cbc63 [PATCH 2/2] anond... |
648 |
ida_remove(&unnamed_dev_ida, slot); |
c63e09ecc Make allocation o... |
649 650 |
if (slot < unnamed_dev_start) unnamed_dev_start = slot; |
1da177e4c Linux-2.6.12-rc2 |
651 652 653 654 |
spin_unlock(&unnamed_dev_lock); } EXPORT_SYMBOL(kill_anon_super); |
1da177e4c Linux-2.6.12-rc2 |
655 656 657 658 659 660 661 662 |
void kill_litter_super(struct super_block *sb) { if (sb->s_root) d_genocide(sb->s_root); kill_anon_super(sb); } EXPORT_SYMBOL(kill_litter_super); |
909e6d947 namespaces: move ... |
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 |
static int ns_test_super(struct super_block *sb, void *data) { return sb->s_fs_info == data; } static int ns_set_super(struct super_block *sb, void *data) { sb->s_fs_info = data; return set_anon_super(sb, NULL); } int get_sb_ns(struct file_system_type *fs_type, int flags, void *data, int (*fill_super)(struct super_block *, void *, int), struct vfsmount *mnt) { struct super_block *sb; sb = sget(fs_type, ns_test_super, ns_set_super, data); if (IS_ERR(sb)) return PTR_ERR(sb); if (!sb->s_root) { int err; sb->s_flags = flags; err = fill_super(sb, data, flags & MS_SILENT ? 1 : 0); if (err) { |
74dbbdd7f New helper: deact... |
689 |
deactivate_locked_super(sb); |
909e6d947 namespaces: move ... |
690 691 692 693 694 695 696 697 698 699 700 |
return err; } sb->s_flags |= MS_ACTIVE; } simple_set_mnt(mnt, sb); return 0; } EXPORT_SYMBOL(get_sb_ns); |
9361401eb [PATCH] BLOCK: Ma... |
701 |
#ifdef CONFIG_BLOCK |
1da177e4c Linux-2.6.12-rc2 |
702 703 704 705 |
static int set_bdev_super(struct super_block *s, void *data) { s->s_bdev = data; s->s_dev = s->s_bdev->bd_dev; |
32a88aa1b fs: Assign bdi in... |
706 707 708 709 710 711 |
/* * We set the bdi here to the queue backing, file systems can * overwrite this in ->fill_super() */ s->s_bdi = &bdev_get_queue(s->s_bdev)->backing_dev_info; |
1da177e4c Linux-2.6.12-rc2 |
712 713 714 715 716 717 718 |
return 0; } static int test_bdev_super(struct super_block *s, void *data) { return (void *)s->s_bdev == data; } |
454e2398b [PATCH] VFS: Perm... |
719 |
int get_sb_bdev(struct file_system_type *fs_type, |
1da177e4c Linux-2.6.12-rc2 |
720 |
int flags, const char *dev_name, void *data, |
454e2398b [PATCH] VFS: Perm... |
721 722 |
int (*fill_super)(struct super_block *, void *, int), struct vfsmount *mnt) |
1da177e4c Linux-2.6.12-rc2 |
723 724 725 |
{ struct block_device *bdev; struct super_block *s; |
30c40d2c0 [PATCH] propagate... |
726 |
fmode_t mode = FMODE_READ; |
1da177e4c Linux-2.6.12-rc2 |
727 |
int error = 0; |
30c40d2c0 [PATCH] propagate... |
728 729 730 731 |
if (!(flags & MS_RDONLY)) mode |= FMODE_WRITE; bdev = open_bdev_exclusive(dev_name, mode, fs_type); |
1da177e4c Linux-2.6.12-rc2 |
732 |
if (IS_ERR(bdev)) |
454e2398b [PATCH] VFS: Perm... |
733 |
return PTR_ERR(bdev); |
1da177e4c Linux-2.6.12-rc2 |
734 735 736 737 738 739 |
/* * once the super is inserted into the list by sget, s_umount * will protect the lockfs code from trying to start a snapshot * while we are mounting */ |
4fadd7bb2 freeze_bdev: kill... |
740 741 742 743 744 745 |
mutex_lock(&bdev->bd_fsfreeze_mutex); if (bdev->bd_fsfreeze_count > 0) { mutex_unlock(&bdev->bd_fsfreeze_mutex); error = -EBUSY; goto error_bdev; } |
1da177e4c Linux-2.6.12-rc2 |
746 |
s = sget(fs_type, test_bdev_super, set_bdev_super, bdev); |
4fadd7bb2 freeze_bdev: kill... |
747 |
mutex_unlock(&bdev->bd_fsfreeze_mutex); |
1da177e4c Linux-2.6.12-rc2 |
748 |
if (IS_ERR(s)) |
454e2398b [PATCH] VFS: Perm... |
749 |
goto error_s; |
1da177e4c Linux-2.6.12-rc2 |
750 751 752 |
if (s->s_root) { if ((flags ^ s->s_flags) & MS_RDONLY) { |
74dbbdd7f New helper: deact... |
753 |
deactivate_locked_super(s); |
454e2398b [PATCH] VFS: Perm... |
754 755 |
error = -EBUSY; goto error_bdev; |
1da177e4c Linux-2.6.12-rc2 |
756 |
} |
454e2398b [PATCH] VFS: Perm... |
757 |
|
30c40d2c0 [PATCH] propagate... |
758 |
close_bdev_exclusive(bdev, mode); |
1da177e4c Linux-2.6.12-rc2 |
759 760 761 762 |
} else { char b[BDEVNAME_SIZE]; s->s_flags = flags; |
30c40d2c0 [PATCH] propagate... |
763 |
s->s_mode = mode; |
1da177e4c Linux-2.6.12-rc2 |
764 |
strlcpy(s->s_id, bdevname(bdev, b), sizeof(s->s_id)); |
e78c9a004 [PATCH] fs: remov... |
765 |
sb_set_blocksize(s, block_size(bdev)); |
9b04c997b [PATCH] vfs: MS_V... |
766 |
error = fill_super(s, data, flags & MS_SILENT ? 1 : 0); |
1da177e4c Linux-2.6.12-rc2 |
767 |
if (error) { |
74dbbdd7f New helper: deact... |
768 |
deactivate_locked_super(s); |
454e2398b [PATCH] VFS: Perm... |
769 |
goto error; |
fa675765a Revert mount/umou... |
770 |
} |
454e2398b [PATCH] VFS: Perm... |
771 772 |
s->s_flags |= MS_ACTIVE; |
87d8fe1ee add releasepage h... |
773 |
bdev->bd_super = s; |
1da177e4c Linux-2.6.12-rc2 |
774 |
} |
a3ec947c8 vfs: simple_set_m... |
775 776 |
simple_set_mnt(mnt, s); return 0; |
1da177e4c Linux-2.6.12-rc2 |
777 |
|
454e2398b [PATCH] VFS: Perm... |
778 779 780 |
error_s: error = PTR_ERR(s); error_bdev: |
30c40d2c0 [PATCH] propagate... |
781 |
close_bdev_exclusive(bdev, mode); |
454e2398b [PATCH] VFS: Perm... |
782 783 |
error: return error; |
1da177e4c Linux-2.6.12-rc2 |
784 785 786 787 788 789 790 |
} EXPORT_SYMBOL(get_sb_bdev); void kill_block_super(struct super_block *sb) { struct block_device *bdev = sb->s_bdev; |
30c40d2c0 [PATCH] propagate... |
791 |
fmode_t mode = sb->s_mode; |
1da177e4c Linux-2.6.12-rc2 |
792 |
|
ddbaaf302 NULL noise in fs/... |
793 |
bdev->bd_super = NULL; |
1da177e4c Linux-2.6.12-rc2 |
794 795 |
generic_shutdown_super(sb); sync_blockdev(bdev); |
30c40d2c0 [PATCH] propagate... |
796 |
close_bdev_exclusive(bdev, mode); |
1da177e4c Linux-2.6.12-rc2 |
797 798 799 |
} EXPORT_SYMBOL(kill_block_super); |
9361401eb [PATCH] BLOCK: Ma... |
800 |
#endif |
1da177e4c Linux-2.6.12-rc2 |
801 |
|
454e2398b [PATCH] VFS: Perm... |
802 |
int get_sb_nodev(struct file_system_type *fs_type, |
1da177e4c Linux-2.6.12-rc2 |
803 |
int flags, void *data, |
454e2398b [PATCH] VFS: Perm... |
804 805 |
int (*fill_super)(struct super_block *, void *, int), struct vfsmount *mnt) |
1da177e4c Linux-2.6.12-rc2 |
806 807 808 809 810 |
{ int error; struct super_block *s = sget(fs_type, NULL, set_anon_super, NULL); if (IS_ERR(s)) |
454e2398b [PATCH] VFS: Perm... |
811 |
return PTR_ERR(s); |
1da177e4c Linux-2.6.12-rc2 |
812 813 |
s->s_flags = flags; |
9b04c997b [PATCH] vfs: MS_V... |
814 |
error = fill_super(s, data, flags & MS_SILENT ? 1 : 0); |
1da177e4c Linux-2.6.12-rc2 |
815 |
if (error) { |
74dbbdd7f New helper: deact... |
816 |
deactivate_locked_super(s); |
454e2398b [PATCH] VFS: Perm... |
817 |
return error; |
1da177e4c Linux-2.6.12-rc2 |
818 819 |
} s->s_flags |= MS_ACTIVE; |
a3ec947c8 vfs: simple_set_m... |
820 821 |
simple_set_mnt(mnt, s); return 0; |
1da177e4c Linux-2.6.12-rc2 |
822 823 824 825 826 827 828 829 |
} EXPORT_SYMBOL(get_sb_nodev); static int compare_single(struct super_block *s, void *p) { return 1; } |
454e2398b [PATCH] VFS: Perm... |
830 |
int get_sb_single(struct file_system_type *fs_type, |
1da177e4c Linux-2.6.12-rc2 |
831 |
int flags, void *data, |
454e2398b [PATCH] VFS: Perm... |
832 833 |
int (*fill_super)(struct super_block *, void *, int), struct vfsmount *mnt) |
1da177e4c Linux-2.6.12-rc2 |
834 835 836 837 838 839 |
{ struct super_block *s; int error; s = sget(fs_type, compare_single, set_anon_super, NULL); if (IS_ERR(s)) |
454e2398b [PATCH] VFS: Perm... |
840 |
return PTR_ERR(s); |
1da177e4c Linux-2.6.12-rc2 |
841 842 |
if (!s->s_root) { s->s_flags = flags; |
9b04c997b [PATCH] vfs: MS_V... |
843 |
error = fill_super(s, data, flags & MS_SILENT ? 1 : 0); |
1da177e4c Linux-2.6.12-rc2 |
844 |
if (error) { |
74dbbdd7f New helper: deact... |
845 |
deactivate_locked_super(s); |
454e2398b [PATCH] VFS: Perm... |
846 |
return error; |
1da177e4c Linux-2.6.12-rc2 |
847 848 |
} s->s_flags |= MS_ACTIVE; |
9329d1bea vfs: get_sb_singl... |
849 850 |
} else { do_remount_sb(s, flags, data, 0); |
1da177e4c Linux-2.6.12-rc2 |
851 |
} |
a3ec947c8 vfs: simple_set_m... |
852 853 |
simple_set_mnt(mnt, s); return 0; |
1da177e4c Linux-2.6.12-rc2 |
854 855 856 857 858 |
} EXPORT_SYMBOL(get_sb_single); struct vfsmount * |
bb4a58bf4 VFS: Add GPL_EXPO... |
859 |
vfs_kern_mount(struct file_system_type *type, int flags, const char *name, void *data) |
1da177e4c Linux-2.6.12-rc2 |
860 |
{ |
1da177e4c Linux-2.6.12-rc2 |
861 |
struct vfsmount *mnt; |
1da177e4c Linux-2.6.12-rc2 |
862 |
char *secdata = NULL; |
454e2398b [PATCH] VFS: Perm... |
863 |
int error; |
1da177e4c Linux-2.6.12-rc2 |
864 865 866 |
if (!type) return ERR_PTR(-ENODEV); |
1da177e4c Linux-2.6.12-rc2 |
867 |
|
454e2398b [PATCH] VFS: Perm... |
868 |
error = -ENOMEM; |
1da177e4c Linux-2.6.12-rc2 |
869 870 871 |
mnt = alloc_vfsmnt(name); if (!mnt) goto out; |
8089352a1 Mirror MS_KERNMOU... |
872 873 |
if (flags & MS_KERNMOUNT) mnt->mnt_flags = MNT_INTERNAL; |
e00075298 LSM/SELinux: Inte... |
874 |
if (data && !(type->fs_flags & FS_BINARY_MOUNTDATA)) { |
1da177e4c Linux-2.6.12-rc2 |
875 |
secdata = alloc_secdata(); |
454e2398b [PATCH] VFS: Perm... |
876 |
if (!secdata) |
1da177e4c Linux-2.6.12-rc2 |
877 |
goto out_mnt; |
1da177e4c Linux-2.6.12-rc2 |
878 |
|
e00075298 LSM/SELinux: Inte... |
879 |
error = security_sb_copy_data(data, secdata); |
454e2398b [PATCH] VFS: Perm... |
880 |
if (error) |
1da177e4c Linux-2.6.12-rc2 |
881 |
goto out_free_secdata; |
1da177e4c Linux-2.6.12-rc2 |
882 |
} |
454e2398b [PATCH] VFS: Perm... |
883 884 |
error = type->get_sb(type, flags, name, data, mnt); if (error < 0) |
1da177e4c Linux-2.6.12-rc2 |
885 |
goto out_free_secdata; |
b4c07bce7 hugetlbfs: handle... |
886 |
BUG_ON(!mnt->mnt_sb); |
5129a469a Catch filesystems... |
887 |
WARN_ON(!mnt->mnt_sb->s_bdi); |
454e2398b [PATCH] VFS: Perm... |
888 |
|
5129a469a Catch filesystems... |
889 890 891 |
error = security_sb_kern_mount(mnt->mnt_sb, flags, secdata); if (error) goto out_sb; |
454e2398b [PATCH] VFS: Perm... |
892 |
|
42cb56ae2 vfs: change sb->s... |
893 894 895 896 897 898 899 900 901 902 |
/* * filesystems should never set s_maxbytes larger than MAX_LFS_FILESIZE * but s_maxbytes was an unsigned long long for many releases. Throw * this warning for a little while to try and catch filesystems that * violate this rule. This warning should be either removed or * converted to a BUG() in 2.6.34. */ WARN((mnt->mnt_sb->s_maxbytes < 0), "%s set sb->s_maxbytes to " "negative value (%lld) ", type->name, mnt->mnt_sb->s_maxbytes); |
454e2398b [PATCH] VFS: Perm... |
903 |
mnt->mnt_mountpoint = mnt->mnt_root; |
1da177e4c Linux-2.6.12-rc2 |
904 |
mnt->mnt_parent = mnt; |
454e2398b [PATCH] VFS: Perm... |
905 |
up_write(&mnt->mnt_sb->s_umount); |
8680e22f2 [PATCH] VFS: memo... |
906 |
free_secdata(secdata); |
1da177e4c Linux-2.6.12-rc2 |
907 908 |
return mnt; out_sb: |
454e2398b [PATCH] VFS: Perm... |
909 |
dput(mnt->mnt_root); |
74dbbdd7f New helper: deact... |
910 |
deactivate_locked_super(mnt->mnt_sb); |
1da177e4c Linux-2.6.12-rc2 |
911 912 913 914 915 |
out_free_secdata: free_secdata(secdata); out_mnt: free_vfsmnt(mnt); out: |
454e2398b [PATCH] VFS: Perm... |
916 |
return ERR_PTR(error); |
1da177e4c Linux-2.6.12-rc2 |
917 |
} |
bb4a58bf4 VFS: Add GPL_EXPO... |
918 |
EXPORT_SYMBOL_GPL(vfs_kern_mount); |
18e9e5104 Introduce freeze_... |
919 |
/** |
7000d3c42 fs/super: fix ker... |
920 921 |
* freeze_super - lock the filesystem and force it into a consistent state * @sb: the super to lock |
18e9e5104 Introduce freeze_... |
922 923 924 925 926 927 928 929 930 931 932 933 934 935 936 937 938 939 940 941 942 943 944 945 946 947 948 949 950 951 952 953 954 955 956 957 958 959 960 961 962 963 964 965 966 967 968 969 970 971 972 973 974 975 976 977 978 979 980 981 982 983 984 985 986 987 988 989 990 991 992 993 994 995 996 997 998 999 1000 1001 1002 1003 1004 1005 1006 1007 1008 1009 |
* * Syncs the super to make sure the filesystem is consistent and calls the fs's * freeze_fs. Subsequent calls to this without first thawing the fs will return * -EBUSY. */ int freeze_super(struct super_block *sb) { int ret; atomic_inc(&sb->s_active); down_write(&sb->s_umount); if (sb->s_frozen) { deactivate_locked_super(sb); return -EBUSY; } if (sb->s_flags & MS_RDONLY) { sb->s_frozen = SB_FREEZE_TRANS; smp_wmb(); up_write(&sb->s_umount); return 0; } sb->s_frozen = SB_FREEZE_WRITE; smp_wmb(); sync_filesystem(sb); sb->s_frozen = SB_FREEZE_TRANS; smp_wmb(); sync_blockdev(sb->s_bdev); if (sb->s_op->freeze_fs) { ret = sb->s_op->freeze_fs(sb); if (ret) { printk(KERN_ERR "VFS:Filesystem freeze failed "); sb->s_frozen = SB_UNFROZEN; deactivate_locked_super(sb); return ret; } } up_write(&sb->s_umount); return 0; } EXPORT_SYMBOL(freeze_super); /** * thaw_super -- unlock filesystem * @sb: the super to thaw * * Unlocks the filesystem and marks it writeable again after freeze_super(). */ int thaw_super(struct super_block *sb) { int error; down_write(&sb->s_umount); if (sb->s_frozen == SB_UNFROZEN) { up_write(&sb->s_umount); return -EINVAL; } if (sb->s_flags & MS_RDONLY) goto out; if (sb->s_op->unfreeze_fs) { error = sb->s_op->unfreeze_fs(sb); if (error) { printk(KERN_ERR "VFS:Filesystem thaw failed "); sb->s_frozen = SB_FREEZE_TRANS; up_write(&sb->s_umount); return error; } } out: sb->s_frozen = SB_UNFROZEN; smp_wmb(); wake_up(&sb->s_wait_unfrozen); deactivate_locked_super(sb); return 0; } EXPORT_SYMBOL(thaw_super); |
79c0b2df7 add filesystem su... |
1010 1011 1012 1013 1014 1015 1016 1017 1018 1019 1020 1021 1022 1023 1024 1025 1026 1027 1028 1029 1030 1031 |
static struct vfsmount *fs_set_subtype(struct vfsmount *mnt, const char *fstype) { int err; const char *subtype = strchr(fstype, '.'); if (subtype) { subtype++; err = -EINVAL; if (!subtype[0]) goto err; } else subtype = ""; mnt->mnt_sb->s_subtype = kstrdup(subtype, GFP_KERNEL); err = -ENOMEM; if (!mnt->mnt_sb->s_subtype) goto err; return mnt; err: mntput(mnt); return ERR_PTR(err); } |
bb4a58bf4 VFS: Add GPL_EXPO... |
1032 1033 1034 1035 1036 1037 1038 1039 |
struct vfsmount * do_kern_mount(const char *fstype, int flags, const char *name, void *data) { struct file_system_type *type = get_fs_type(fstype); struct vfsmount *mnt; if (!type) return ERR_PTR(-ENODEV); mnt = vfs_kern_mount(type, flags, name, data); |
79c0b2df7 add filesystem su... |
1040 1041 1042 |
if (!IS_ERR(mnt) && (type->fs_flags & FS_HAS_SUBTYPE) && !mnt->mnt_sb->s_subtype) mnt = fs_set_subtype(mnt, fstype); |
bb4a58bf4 VFS: Add GPL_EXPO... |
1043 1044 1045 |
put_filesystem(type); return mnt; } |
8a4e98d9d [PATCH] restore e... |
1046 |
EXPORT_SYMBOL_GPL(do_kern_mount); |
bb4a58bf4 VFS: Add GPL_EXPO... |
1047 |
|
8bf9725c2 pid namespaces: i... |
1048 |
struct vfsmount *kern_mount_data(struct file_system_type *type, void *data) |
1da177e4c Linux-2.6.12-rc2 |
1049 |
{ |
8bf9725c2 pid namespaces: i... |
1050 |
return vfs_kern_mount(type, MS_KERNMOUNT, type->name, data); |
1da177e4c Linux-2.6.12-rc2 |
1051 |
} |
8bf9725c2 pid namespaces: i... |
1052 |
EXPORT_SYMBOL_GPL(kern_mount_data); |