diff options
Diffstat (limited to 'fs/super.c')
| -rw-r--r-- | fs/super.c | 44 |
1 files changed, 42 insertions, 2 deletions
diff --git a/fs/super.c b/fs/super.c index fd9c02f543eb..83c5c8a60f5f 100644 --- a/fs/super.c +++ b/fs/super.c @@ -36,6 +36,7 @@ #include <linux/user_namespace.h> #include "internal.h" +static int thaw_super_locked(struct super_block *sb); static LIST_HEAD(super_blocks); static DEFINE_SPINLOCK(sb_lock); @@ -934,6 +935,40 @@ void emergency_remount(void) } } +static void do_thaw_all_callback(struct super_block *sb) +{ + down_write(&sb->s_umount); + if (sb->s_root && sb->s_flags & MS_BORN) { + emergency_thaw_bdev(sb); + thaw_super_locked(sb); + } else { + up_write(&sb->s_umount); + } +} + +static void do_thaw_all(struct work_struct *work) +{ + __iterate_supers(do_thaw_all_callback); + kfree(work); + printk(KERN_WARNING "Emergency Thaw complete\n"); +} + +/** + * emergency_thaw_all -- forcibly thaw every frozen filesystem + * + * Used for emergency unfreeze of all filesystems via SysRq + */ +void emergency_thaw_all(void) +{ + struct work_struct *work; + + work = kmalloc(sizeof(*work), GFP_ATOMIC); + if (work) { + INIT_WORK(work, do_thaw_all); + schedule_work(work); + } +} + /* * Unnamed block devices are dummy devices used by virtual * filesystems which don't use real block-devices. -- jrs @@ -1503,11 +1538,10 @@ EXPORT_SYMBOL(freeze_super); * * Unlocks the filesystem and marks it writeable again after freeze_super(). */ -int thaw_super(struct super_block *sb) +static int thaw_super_locked(struct super_block *sb) { int error; - down_write(&sb->s_umount); if (sb->s_writers.frozen != SB_FREEZE_COMPLETE) { up_write(&sb->s_umount); return -EINVAL; @@ -1538,4 +1572,10 @@ out: deactivate_locked_super(sb); return 0; } + +int thaw_super(struct super_block *sb) +{ + down_write(&sb->s_umount); + return thaw_super_locked(sb); +} EXPORT_SYMBOL(thaw_super); |