* Added kerneld support: Jacques Gelinas and Bjorn Ekwall
* Added change_root: Werner Almesberger & Hans Lermen, Feb '96
* Added options to /proc/mounts:
- * Torbjörn Lindh (torbjorn.lindh@gopta.se), April 14, 1996.
+ * Torbjörn Lindh (torbjorn.lindh@gopta.se), April 14, 1996.
* Added devfs support: Richard Gooch <rgooch@atnf.csiro.au>, 13-JAN-1998
* Heavily rewritten for 'one fs - one tree' dcache architecture. AV, Mar 2000
*/
#include <linux/module.h>
#include <linux/slab.h>
-#include <linux/init.h>
-#include <linux/smp_lock.h>
#include <linux/acct.h>
#include <linux/blkdev.h>
#include <linux/quotaops.h>
-#include <linux/namei.h>
-#include <linux/buffer_head.h> /* for fsync_super() */
#include <linux/mount.h>
#include <linux/security.h>
-#include <linux/syscalls.h>
-#include <linux/vfs.h>
#include <linux/writeback.h> /* for the emergency remount stuff */
#include <linux/idr.h>
-#include <linux/kobject.h>
#include <linux/mutex.h>
-#include <asm/uaccess.h>
+#include <linux/backing-dev.h>
+#include "internal.h"
-void get_filesystem(struct file_system_type *fs);
-void put_filesystem(struct file_system_type *fs);
-struct file_system_type *get_fs_type(const char *name);
-
LIST_HEAD(super_blocks);
DEFINE_SPINLOCK(sb_lock);
static struct super_block *alloc_super(struct file_system_type *type)
{
struct super_block *s = kzalloc(sizeof(struct super_block), GFP_USER);
- static struct super_operations default_op;
+ static const struct super_operations default_op;
if (s) {
if (security_sb_alloc(s)) {
s = NULL;
goto out;
}
- INIT_LIST_HEAD(&s->s_dirty);
- INIT_LIST_HEAD(&s->s_io);
INIT_LIST_HEAD(&s->s_files);
INIT_LIST_HEAD(&s->s_instances);
INIT_HLIST_HEAD(&s->s_anon);
INIT_LIST_HEAD(&s->s_inodes);
+ INIT_LIST_HEAD(&s->s_dentry_lru);
init_rwsem(&s->s_umount);
mutex_init(&s->s_lock);
lockdep_set_class(&s->s_umount, &type->s_umount_key);
* lock ordering than usbfs:
*/
lockdep_set_class(&s->s_lock, &type->s_lock_key);
- down_write(&s->s_umount);
- s->s_count = S_BIAS;
+ /*
+ * 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);
+ s->s_count = 1;
atomic_set(&s->s_active, 1);
mutex_init(&s->s_vfs_rename_mutex);
+ lockdep_set_class(&s->s_vfs_rename_mutex, &type->s_vfs_rename_key);
mutex_init(&s->s_dquot.dqio_mutex);
mutex_init(&s->s_dquot.dqonoff_mutex);
init_rwsem(&s->s_dquot.dqptr_sem);
static inline void destroy_super(struct super_block *s)
{
security_sb_free(s);
+ kfree(s->s_subtype);
+ kfree(s->s_options);
kfree(s);
}
/* Superblock refcounting */
/*
- * Drop a superblock's refcount. Returns non-zero if the superblock was
- * destroyed. The caller must hold sb_lock.
+ * Drop a superblock's refcount. The caller must hold sb_lock.
*/
-int __put_super(struct super_block *sb)
+void __put_super(struct super_block *sb)
{
- int ret = 0;
-
if (!--sb->s_count) {
+ list_del_init(&sb->s_list);
destroy_super(sb);
- ret = 1;
}
- return ret;
-}
-
-/*
- * Drop a superblock's refcount.
- * Returns non-zero if the superblock is about to be destroyed and
- * at least is already removed from super_blocks list, so if we are
- * making a loop through super blocks then we need to restart.
- * The caller must hold sb_lock.
- */
-int __put_super_and_need_restart(struct super_block *sb)
-{
- /* check for race with generic_shutdown_super() */
- if (list_empty(&sb->s_list)) {
- /* super block is removed, need to restart... */
- __put_super(sb);
- return 1;
- }
- /* can't be the last, since s_list is still in use */
- sb->s_count--;
- BUG_ON(sb->s_count == 0);
- return 0;
}
/**
* Drops a temporary reference, frees superblock if there's no
* references left.
*/
-static void put_super(struct super_block *sb)
+void put_super(struct super_block *sb)
{
spin_lock(&sb_lock);
__put_super(sb);
/**
- * deactivate_super - drop an active reference to superblock
+ * deactivate_locked_super - drop an active reference to superblock
* @s: superblock to deactivate
*
- * Drops an active reference to superblock, acquiring a temprory one if
- * there is no active references left. In that case we lock superblock,
+ * Drops an active reference to superblock, converting it into a temprory
+ * one if there is no other active references left. In that case we
* tell fs driver to shut it down and drop the temporary reference we
* had just acquired.
+ *
+ * Caller holds exclusive lock on superblock; that lock is released.
*/
-void deactivate_super(struct super_block *s)
+void deactivate_locked_super(struct super_block *s)
{
struct file_system_type *fs = s->s_type;
- if (atomic_dec_and_lock(&s->s_active, &sb_lock)) {
- s->s_count -= S_BIAS-1;
- spin_unlock(&sb_lock);
- DQUOT_OFF(s);
- down_write(&s->s_umount);
+ if (atomic_dec_and_test(&s->s_active)) {
+ vfs_dq_off(s, 0);
fs->kill_sb(s);
put_filesystem(fs);
put_super(s);
+ } else {
+ up_write(&s->s_umount);
+ }
+}
+
+EXPORT_SYMBOL(deactivate_locked_super);
+
+/**
+ * deactivate_super - drop an active reference to superblock
+ * @s: superblock to deactivate
+ *
+ * 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.
+ */
+void deactivate_super(struct super_block *s)
+{
+ if (!atomic_add_unless(&s->s_active, -1, 1)) {
+ down_write(&s->s_umount);
+ deactivate_locked_super(s);
}
}
*/
static int grab_super(struct super_block *s) __releases(sb_lock)
{
+ if (atomic_inc_not_zero(&s->s_active)) {
+ spin_unlock(&sb_lock);
+ return 1;
+ }
+ /* it's going away */
s->s_count++;
spin_unlock(&sb_lock);
+ /* wait for it to die */
down_write(&s->s_umount);
- if (s->s_root) {
- spin_lock(&sb_lock);
- if (s->s_count > S_BIAS) {
- atomic_inc(&s->s_active);
- s->s_count--;
- spin_unlock(&sb_lock);
- return 1;
- }
- spin_unlock(&sb_lock);
- }
up_write(&s->s_umount);
put_super(s);
- yield();
return 0;
}
EXPORT_SYMBOL(lock_super);
EXPORT_SYMBOL(unlock_super);
-/*
- * Write out and wait upon all dirty data associated with this
- * superblock. Filesystem data as well as the underlying block
- * device. Takes the superblock lock. Requires a second blkdev
- * flush by the caller to complete the operation.
- */
-void __fsync_super(struct super_block *sb)
-{
- sync_inodes_sb(sb, 0);
- DQUOT_SYNC(sb);
- lock_super(sb);
- if (sb->s_dirt && sb->s_op->write_super)
- sb->s_op->write_super(sb);
- unlock_super(sb);
- if (sb->s_op->sync_fs)
- sb->s_op->sync_fs(sb, 1);
- sync_blockdev(sb->s_bdev);
- sync_inodes_sb(sb, 1);
-}
-
-/*
- * Write out and wait upon all dirty data associated with this
- * superblock. Filesystem data as well as the underlying block
- * device. Takes the superblock lock.
- */
-int fsync_super(struct super_block *sb)
-{
- __fsync_super(sb);
- return sync_blockdev(sb->s_bdev);
-}
-
/**
* generic_shutdown_super - common helper for ->kill_sb()
* @sb: superblock to kill
{
const struct super_operations *sop = sb->s_op;
+
if (sb->s_root) {
shrink_dcache_for_umount(sb);
- fsync_super(sb);
- lock_super(sb);
+ sync_filesystem(sb);
+ get_fs_excl();
sb->s_flags &= ~MS_ACTIVE;
+
/* bad name - it should be evict_inodes() */
invalidate_inodes(sb);
- lock_kernel();
- if (sop->write_super && sb->s_dirt)
- sop->write_super(sb);
if (sop->put_super)
sop->put_super(sb);
"Self-destruct in 5 seconds. Have a nice day...\n",
sb->s_id);
}
-
- unlock_kernel();
- unlock_super(sb);
+ put_fs_excl();
}
spin_lock(&sb_lock);
/* should be initialized for __put_super_and_need_restart() */
- list_del_init(&sb->s_list);
- list_del(&sb->s_instances);
+ list_del_init(&sb->s_instances);
spin_unlock(&sb_lock);
up_write(&sb->s_umount);
}
void *data)
{
struct super_block *s = NULL;
- struct list_head *p;
+ struct super_block *old;
int err;
retry:
spin_lock(&sb_lock);
- if (test) list_for_each(p, &type->fs_supers) {
- struct super_block *old;
- old = list_entry(p, struct super_block, s_instances);
- if (!test(old, data))
- continue;
- if (!grab_super(old))
- goto retry;
- if (s)
- destroy_super(s);
- return old;
+ if (test) {
+ list_for_each_entry(old, &type->fs_supers, s_instances) {
+ if (!test(old, data))
+ continue;
+ if (!grab_super(old))
+ goto retry;
+ if (s) {
+ up_write(&s->s_umount);
+ destroy_super(s);
+ }
+ down_write(&old->s_umount);
+ return old;
+ }
}
if (!s) {
spin_unlock(&sb_lock);
err = set(s, data);
if (err) {
spin_unlock(&sb_lock);
+ up_write(&s->s_umount);
destroy_super(s);
return ERR_PTR(err);
}
EXPORT_SYMBOL(drop_super);
-static inline void write_super(struct super_block *sb)
-{
- lock_super(sb);
- if (sb->s_root && sb->s_dirt)
- if (sb->s_op->write_super)
- sb->s_op->write_super(sb);
- unlock_super(sb);
-}
-
-/*
+/**
+ * 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.
+ *
* 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)
{
- struct super_block *sb;
+ struct super_block *sb, *n;
spin_lock(&sb_lock);
-restart:
- list_for_each_entry(sb, &super_blocks, s_list) {
- if (sb->s_dirt) {
+ list_for_each_entry_safe(sb, n, &super_blocks, s_list) {
+ if (list_empty(&sb->s_instances))
+ continue;
+ if (sb->s_op->write_super && sb->s_dirt) {
sb->s_count++;
spin_unlock(&sb_lock);
+
down_read(&sb->s_umount);
- write_super(sb);
+ if (sb->s_root && sb->s_dirt)
+ sb->s_op->write_super(sb);
up_read(&sb->s_umount);
+
spin_lock(&sb_lock);
- if (__put_super_and_need_restart(sb))
- goto restart;
+ __put_super(sb);
}
}
spin_unlock(&sb_lock);
}
-/*
- * Call the ->sync_fs super_op against all filesytems which are r/w and
- * which implement it.
- *
- * This operation is careful to avoid the livelock which could easily happen
- * if two or more filesystems are being continuously dirtied. s_need_sync_fs
- * is used only here. We set it against all filesystems and then clear it as
- * we sync them. So redirtied filesystems are skipped.
- *
- * But if process A is currently running sync_filesytems and then process B
- * calls sync_filesystems as well, process B will set all the s_need_sync_fs
- * flags again, which will cause process A to resync everything. Fix that with
- * a local mutex.
+/**
+ * iterate_supers - call function for all active superblocks
+ * @f: function to call
+ * @arg: argument to pass to it
*
- * (Fabian) Avoid sync_fs with clean fs & wait mode 0
+ * Scans the superblock list and calls given function, passing it
+ * locked superblock and given argument.
*/
-void sync_filesystems(int wait)
+void iterate_supers(void (*f)(struct super_block *, void *), void *arg)
{
- struct super_block *sb;
- static DEFINE_MUTEX(mutex);
+ struct super_block *sb, *n;
- mutex_lock(&mutex); /* Could be down_interruptible */
spin_lock(&sb_lock);
- list_for_each_entry(sb, &super_blocks, s_list) {
- if (!sb->s_op->sync_fs)
- continue;
- if (sb->s_flags & MS_RDONLY)
- continue;
- sb->s_need_sync_fs = 1;
- }
-
-restart:
- list_for_each_entry(sb, &super_blocks, s_list) {
- if (!sb->s_need_sync_fs)
+ list_for_each_entry_safe(sb, n, &super_blocks, s_list) {
+ if (list_empty(&sb->s_instances))
continue;
- sb->s_need_sync_fs = 0;
- if (sb->s_flags & MS_RDONLY)
- continue; /* hm. Was remounted r/o meanwhile */
sb->s_count++;
spin_unlock(&sb_lock);
+
down_read(&sb->s_umount);
- if (sb->s_root && (wait || sb->s_dirt))
- sb->s_op->sync_fs(sb, wait);
+ if (sb->s_root)
+ f(sb, arg);
up_read(&sb->s_umount);
- /* restart only when sb is no longer on the list */
+
spin_lock(&sb_lock);
- if (__put_super_and_need_restart(sb))
- goto restart;
+ __put_super(sb);
}
spin_unlock(&sb_lock);
- mutex_unlock(&mutex);
}
/**
* mounted on the device given. %NULL is returned if no match is found.
*/
-struct super_block * get_super(struct block_device *bdev)
+struct super_block *get_super(struct block_device *bdev)
{
struct super_block *sb;
spin_lock(&sb_lock);
rescan:
list_for_each_entry(sb, &super_blocks, s_list) {
+ if (list_empty(&sb->s_instances))
+ continue;
if (sb->s_bdev == bdev) {
sb->s_count++;
spin_unlock(&sb_lock);
down_read(&sb->s_umount);
+ /* still alive? */
if (sb->s_root)
return sb;
up_read(&sb->s_umount);
- /* restart only when sb is no longer on the list */
+ /* nope, got unmounted */
spin_lock(&sb_lock);
- if (__put_super_and_need_restart(sb))
- goto rescan;
+ __put_super(sb);
+ goto rescan;
}
}
spin_unlock(&sb_lock);
}
EXPORT_SYMBOL(get_super);
+
+/**
+ * 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
+ * reference or %NULL if none was found.
+ */
+struct super_block *get_active_super(struct block_device *bdev)
+{
+ struct super_block *sb;
+
+ if (!bdev)
+ return NULL;
+
+restart:
+ spin_lock(&sb_lock);
+ list_for_each_entry(sb, &super_blocks, s_list) {
+ if (list_empty(&sb->s_instances))
+ continue;
+ if (sb->s_bdev == bdev) {
+ if (grab_super(sb)) /* drops sb_lock */
+ return sb;
+ else
+ goto restart;
+ }
+ }
+ spin_unlock(&sb_lock);
+ return NULL;
+}
-struct super_block * user_get_super(dev_t dev)
+struct super_block *user_get_super(dev_t dev)
{
struct super_block *sb;
spin_lock(&sb_lock);
rescan:
list_for_each_entry(sb, &super_blocks, s_list) {
+ if (list_empty(&sb->s_instances))
+ continue;
if (sb->s_dev == dev) {
sb->s_count++;
spin_unlock(&sb_lock);
down_read(&sb->s_umount);
+ /* still alive? */
if (sb->s_root)
return sb;
up_read(&sb->s_umount);
- /* restart only when sb is no longer on the list */
+ /* nope, got unmounted */
spin_lock(&sb_lock);
- if (__put_super_and_need_restart(sb))
- goto rescan;
+ __put_super(sb);
+ goto rescan;
}
}
spin_unlock(&sb_lock);
return NULL;
}
-asmlinkage long sys_ustat(unsigned dev, struct ustat __user * ubuf)
-{
- struct super_block *s;
- struct ustat tmp;
- struct kstatfs sbuf;
- int err = -EINVAL;
-
- s = user_get_super(new_decode_dev(dev));
- if (s == NULL)
- goto out;
- err = vfs_statfs(s->s_root, &sbuf);
- drop_super(s);
- if (err)
- goto out;
-
- memset(&tmp,0,sizeof(struct ustat));
- tmp.f_tfree = sbuf.f_bfree;
- tmp.f_tinode = sbuf.f_ffree;
-
- err = copy_to_user(ubuf,&tmp,sizeof(struct ustat)) ? -EFAULT : 0;
-out:
- return err;
-}
-
-/**
- * mark_files_ro
- * @sb: superblock in question
- *
- * All files are marked read/only. We don't care about pending
- * delete files so this should be used in 'force' mode only
- */
-
-static void mark_files_ro(struct super_block *sb)
-{
- struct file *f;
-
- file_list_lock();
- list_for_each_entry(f, &sb->s_files, f_u.fu_list) {
- if (S_ISREG(f->f_path.dentry->d_inode->i_mode) && file_count(f))
- f->f_mode &= ~FMODE_WRITE;
- }
- file_list_unlock();
-}
-
/**
* do_remount_sb - asks filesystem to change mount options.
* @sb: superblock in question
int do_remount_sb(struct super_block *sb, int flags, void *data, int force)
{
int retval;
-
+ int remount_rw, remount_ro;
+
+ if (sb->s_frozen != SB_UNFROZEN)
+ return -EBUSY;
+
#ifdef CONFIG_BLOCK
if (!(flags & MS_RDONLY) && bdev_read_only(sb->s_bdev))
return -EACCES;
#endif
+
if (flags & MS_RDONLY)
acct_auto_close(sb);
shrink_dcache_sb(sb);
- fsync_super(sb);
+ sync_filesystem(sb);
+
+ remount_ro = (flags & MS_RDONLY) && !(sb->s_flags & MS_RDONLY);
+ remount_rw = !(flags & MS_RDONLY) && (sb->s_flags & MS_RDONLY);
/* If we are remounting RDONLY and current sb is read/write,
make sure there are no rw files opened */
- if ((flags & MS_RDONLY) && !(sb->s_flags & MS_RDONLY)) {
+ if (remount_ro) {
if (force)
mark_files_ro(sb);
else if (!fs_may_remount_ro(sb))
return -EBUSY;
+ retval = vfs_dq_off(sb, 1);
+ if (retval < 0 && retval != -ENOSYS)
+ return -EBUSY;
}
if (sb->s_op->remount_fs) {
- lock_super(sb);
retval = sb->s_op->remount_fs(sb, &flags, data);
- unlock_super(sb);
if (retval)
return retval;
}
sb->s_flags = (sb->s_flags & ~MS_RMT_MASK) | (flags & MS_RMT_MASK);
+ if (remount_rw)
+ vfs_dq_quota_on_remount(sb);
+ /*
+ * 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);
return 0;
}
-static void do_emergency_remount(unsigned long foo)
+static void do_emergency_remount(struct work_struct *work)
{
- struct super_block *sb;
+ struct super_block *sb, *n;
spin_lock(&sb_lock);
- list_for_each_entry(sb, &super_blocks, s_list) {
+ 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);
+ down_write(&sb->s_umount);
if (sb->s_root && sb->s_bdev && !(sb->s_flags & MS_RDONLY)) {
/*
- * ->remount_fs needs lock_kernel().
- *
* What lock protects sb->s_flags??
*/
- lock_kernel();
do_remount_sb(sb, MS_RDONLY, NULL, 1);
- unlock_kernel();
}
- drop_super(sb);
+ up_write(&sb->s_umount);
spin_lock(&sb_lock);
+ __put_super(sb);
}
spin_unlock(&sb_lock);
+ kfree(work);
printk("Emergency Remount complete\n");
}
void emergency_remount(void)
{
- pdflush_operation(do_emergency_remount, 0);
+ struct work_struct *work;
+
+ work = kmalloc(sizeof(*work), GFP_ATOMIC);
+ if (work) {
+ INIT_WORK(work, do_emergency_remount);
+ schedule_work(work);
+ }
}
/*
* filesystems which don't use real block-devices. -- jrs
*/
-static struct idr unnamed_dev_idr;
+static DEFINE_IDA(unnamed_dev_ida);
static DEFINE_SPINLOCK(unnamed_dev_lock);/* protects the above */
+static int unnamed_dev_start = 0; /* don't bother trying below it */
int set_anon_super(struct super_block *s, void *data)
{
int error;
retry:
- if (idr_pre_get(&unnamed_dev_idr, GFP_ATOMIC) == 0)
+ if (ida_pre_get(&unnamed_dev_ida, GFP_ATOMIC) == 0)
return -ENOMEM;
spin_lock(&unnamed_dev_lock);
- error = idr_get_new(&unnamed_dev_idr, NULL, &dev);
+ error = ida_get_new_above(&unnamed_dev_ida, unnamed_dev_start, &dev);
+ if (!error)
+ unnamed_dev_start = dev + 1;
spin_unlock(&unnamed_dev_lock);
if (error == -EAGAIN)
/* We raced and lost with another CPU. */
if ((dev & MAX_ID_MASK) == (1 << MINORBITS)) {
spin_lock(&unnamed_dev_lock);
- idr_remove(&unnamed_dev_idr, dev);
+ ida_remove(&unnamed_dev_ida, dev);
+ if (unnamed_dev_start > dev)
+ unnamed_dev_start = dev;
spin_unlock(&unnamed_dev_lock);
return -EMFILE;
}
s->s_dev = MKDEV(0, dev & MINORMASK);
+ s->s_bdi = &noop_backing_dev_info;
return 0;
}
generic_shutdown_super(sb);
spin_lock(&unnamed_dev_lock);
- idr_remove(&unnamed_dev_idr, slot);
+ ida_remove(&unnamed_dev_ida, slot);
+ if (slot < unnamed_dev_start)
+ unnamed_dev_start = slot;
spin_unlock(&unnamed_dev_lock);
}
EXPORT_SYMBOL(kill_anon_super);
-void __init unnamed_dev_init(void)
-{
- idr_init(&unnamed_dev_idr);
-}
-
void kill_litter_super(struct super_block *sb)
{
if (sb->s_root)
EXPORT_SYMBOL(kill_litter_super);
+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) {
+ deactivate_locked_super(sb);
+ return err;
+ }
+
+ sb->s_flags |= MS_ACTIVE;
+ }
+
+ simple_set_mnt(mnt, sb);
+ return 0;
+}
+
+EXPORT_SYMBOL(get_sb_ns);
+
#ifdef CONFIG_BLOCK
static int set_bdev_super(struct super_block *s, void *data)
{
s->s_bdev = data;
s->s_dev = s->s_bdev->bd_dev;
+
+ /*
+ * 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;
return 0;
}
return (void *)s->s_bdev == data;
}
-static void bdev_uevent(struct block_device *bdev, enum kobject_action action)
-{
- if (bdev->bd_disk) {
- if (bdev->bd_part)
- kobject_uevent(&bdev->bd_part->kobj, action);
- else
- kobject_uevent(&bdev->bd_disk->kobj, action);
- }
-}
-
int get_sb_bdev(struct file_system_type *fs_type,
int flags, const char *dev_name, void *data,
int (*fill_super)(struct super_block *, void *, int),
{
struct block_device *bdev;
struct super_block *s;
+ fmode_t mode = FMODE_READ;
int error = 0;
- bdev = open_bdev_excl(dev_name, flags, fs_type);
+ if (!(flags & MS_RDONLY))
+ mode |= FMODE_WRITE;
+
+ bdev = open_bdev_exclusive(dev_name, mode, fs_type);
if (IS_ERR(bdev))
return PTR_ERR(bdev);
* will protect the lockfs code from trying to start a snapshot
* while we are mounting
*/
- down(&bdev->bd_mount_sem);
+ mutex_lock(&bdev->bd_fsfreeze_mutex);
+ if (bdev->bd_fsfreeze_count > 0) {
+ mutex_unlock(&bdev->bd_fsfreeze_mutex);
+ error = -EBUSY;
+ goto error_bdev;
+ }
s = sget(fs_type, test_bdev_super, set_bdev_super, bdev);
- up(&bdev->bd_mount_sem);
+ mutex_unlock(&bdev->bd_fsfreeze_mutex);
if (IS_ERR(s))
goto error_s;
if (s->s_root) {
if ((flags ^ s->s_flags) & MS_RDONLY) {
- up_write(&s->s_umount);
- deactivate_super(s);
+ deactivate_locked_super(s);
error = -EBUSY;
goto error_bdev;
}
- close_bdev_excl(bdev);
+ close_bdev_exclusive(bdev, mode);
} else {
char b[BDEVNAME_SIZE];
s->s_flags = flags;
+ s->s_mode = mode;
strlcpy(s->s_id, bdevname(bdev, b), sizeof(s->s_id));
sb_set_blocksize(s, block_size(bdev));
error = fill_super(s, data, flags & MS_SILENT ? 1 : 0);
if (error) {
- up_write(&s->s_umount);
- deactivate_super(s);
+ deactivate_locked_super(s);
goto error;
}
s->s_flags |= MS_ACTIVE;
- bdev_uevent(bdev, KOBJ_MOUNT);
+ bdev->bd_super = s;
}
- return simple_set_mnt(mnt, s);
+ simple_set_mnt(mnt, s);
+ return 0;
error_s:
error = PTR_ERR(s);
error_bdev:
- close_bdev_excl(bdev);
+ close_bdev_exclusive(bdev, mode);
error:
return error;
}
void kill_block_super(struct super_block *sb)
{
struct block_device *bdev = sb->s_bdev;
+ fmode_t mode = sb->s_mode;
- bdev_uevent(bdev, KOBJ_UMOUNT);
+ bdev->bd_super = NULL;
generic_shutdown_super(sb);
sync_blockdev(bdev);
- close_bdev_excl(bdev);
+ close_bdev_exclusive(bdev, mode);
}
EXPORT_SYMBOL(kill_block_super);
error = fill_super(s, data, flags & MS_SILENT ? 1 : 0);
if (error) {
- up_write(&s->s_umount);
- deactivate_super(s);
+ deactivate_locked_super(s);
return error;
}
s->s_flags |= MS_ACTIVE;
- return simple_set_mnt(mnt, s);
+ simple_set_mnt(mnt, s);
+ return 0;
}
EXPORT_SYMBOL(get_sb_nodev);
s->s_flags = flags;
error = fill_super(s, data, flags & MS_SILENT ? 1 : 0);
if (error) {
- up_write(&s->s_umount);
- deactivate_super(s);
+ deactivate_locked_super(s);
return error;
}
s->s_flags |= MS_ACTIVE;
+ } else {
+ do_remount_sb(s, flags, data, 0);
}
- do_remount_sb(s, flags, data, 0);
- return simple_set_mnt(mnt, s);
+ simple_set_mnt(mnt, s);
+ return 0;
}
EXPORT_SYMBOL(get_sb_single);
if (!mnt)
goto out;
- if (data) {
+ if (flags & MS_KERNMOUNT)
+ mnt->mnt_flags = MNT_INTERNAL;
+
+ if (data && !(type->fs_flags & FS_BINARY_MOUNTDATA)) {
secdata = alloc_secdata();
if (!secdata)
goto out_mnt;
- error = security_sb_copy_data(type, data, secdata);
+ error = security_sb_copy_data(data, secdata);
if (error)
goto out_free_secdata;
}
error = type->get_sb(type, flags, name, data, mnt);
if (error < 0)
goto out_free_secdata;
+ BUG_ON(!mnt->mnt_sb);
+ WARN_ON(!mnt->mnt_sb->s_bdi);
- error = security_sb_kern_mount(mnt->mnt_sb, secdata);
- if (error)
- goto out_sb;
+ error = security_sb_kern_mount(mnt->mnt_sb, flags, secdata);
+ if (error)
+ goto out_sb;
+
+ /*
+ * 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)\n", type->name, mnt->mnt_sb->s_maxbytes);
mnt->mnt_mountpoint = mnt->mnt_root;
mnt->mnt_parent = mnt;
return mnt;
out_sb:
dput(mnt->mnt_root);
- up_write(&mnt->mnt_sb->s_umount);
- deactivate_super(mnt->mnt_sb);
+ deactivate_locked_super(mnt->mnt_sb);
out_free_secdata:
free_secdata(secdata);
out_mnt:
EXPORT_SYMBOL_GPL(vfs_kern_mount);
+/**
+ * freeze_super -- lock the filesystem and force it into a consistent state
+ * @super: the super to lock
+ *
+ * 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\n");
+ 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\n");
+ 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);
+
+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);
+}
+
struct vfsmount *
do_kern_mount(const char *fstype, int flags, const char *name, void *data)
{
if (!type)
return ERR_PTR(-ENODEV);
mnt = vfs_kern_mount(type, flags, name, data);
+ if (!IS_ERR(mnt) && (type->fs_flags & FS_HAS_SUBTYPE) &&
+ !mnt->mnt_sb->s_subtype)
+ mnt = fs_set_subtype(mnt, fstype);
put_filesystem(type);
return mnt;
}
+EXPORT_SYMBOL_GPL(do_kern_mount);
-struct vfsmount *kern_mount(struct file_system_type *type)
+struct vfsmount *kern_mount_data(struct file_system_type *type, void *data)
{
- return vfs_kern_mount(type, 0, type->name, NULL);
+ return vfs_kern_mount(type, MS_KERNMOUNT, type->name, data);
}
-EXPORT_SYMBOL(kern_mount);
+EXPORT_SYMBOL_GPL(kern_mount_data);
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff