#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>
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() */
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.)
spin_lock(&sb_lock);
restart:
list_for_each_entry(sb, &super_blocks, s_list) {
- if (sb->s_dirt) {
+ 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;
if (flags & MS_RDONLY)
acct_auto_close(sb);
shrink_dcache_sb(sb);
- fsync_super(sb);
+ sync_filesystem(sb);
/* If we are remounting RDONLY and current sb is read/write,
make sure there are no rw files opened */
remount_rw = !(flags & MS_RDONLY) && (sb->s_flags & MS_RDONLY);
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;
}
list_for_each_entry(sb, &super_blocks, s_list) {
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);
+ put_super(sb);
spin_lock(&sb_lock);
}
spin_unlock(&sb_lock);
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)
{
if (ida_pre_get(&unnamed_dev_ida, GFP_ATOMIC) == 0)
return -ENOMEM;
spin_lock(&unnamed_dev_lock);
- error = ida_get_new(&unnamed_dev_ida, &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);
ida_remove(&unnamed_dev_ida, dev);
+ if (unnamed_dev_start > dev)
+ unnamed_dev_start = dev;
spin_unlock(&unnamed_dev_lock);
return -EMFILE;
}
generic_shutdown_super(sb);
spin_lock(&unnamed_dev_lock);
ida_remove(&unnamed_dev_ida, slot);
+ if (slot < unnamed_dev_start)
+ unnamed_dev_start = slot;
spin_unlock(&unnamed_dev_lock);
}