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author | Linus Torvalds <torvalds@linux-foundation.org> | 2018-04-12 12:28:32 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2018-04-12 12:28:32 -0700 |
commit | 7214dd4ea9048d2031e14fc552980cecd6573a9e (patch) | |
tree | 18c9ba52d252d29fcfe7d73d9c78205b285f91d0 | |
parent | 19e8a2f875a56009c0ce30389964aca452a85510 (diff) | |
parent | 08fdc8a0138afaf324296a342f32ad26ec465e43 (diff) | |
download | linux-stable-7214dd4ea9048d2031e14fc552980cecd6573a9e.tar.gz linux-stable-7214dd4ea9048d2031e14fc552980cecd6573a9e.tar.bz2 linux-stable-7214dd4ea9048d2031e14fc552980cecd6573a9e.zip |
Merge branch 'work.thaw' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull vfs thaw updates from Al Viro:
"An ancient series that has fallen through the cracks in the previous
cycle"
* 'work.thaw' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
buffer.c: call thaw_super during emergency thaw
vfs: factor sb iteration out of do_emergency_remount
-rw-r--r-- | fs/buffer.c | 25 | ||||
-rw-r--r-- | fs/super.c | 105 | ||||
-rw-r--r-- | include/linux/fs.h | 6 |
3 files changed, 85 insertions, 51 deletions
diff --git a/fs/buffer.c b/fs/buffer.c index f3491074b035..249b83fafe48 100644 --- a/fs/buffer.c +++ b/fs/buffer.c @@ -494,35 +494,12 @@ repeat: return err; } -static void do_thaw_one(struct super_block *sb, void *unused) +void emergency_thaw_bdev(struct super_block *sb) { while (sb->s_bdev && !thaw_bdev(sb->s_bdev, sb)) printk(KERN_WARNING "Emergency Thaw on %pg\n", sb->s_bdev); } -static void do_thaw_all(struct work_struct *work) -{ - iterate_supers(do_thaw_one, NULL); - 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); - } -} - /** * sync_mapping_buffers - write out & wait upon a mapping's "associated" buffers * @mapping: the mapping which wants those buffers written diff --git a/fs/super.c b/fs/super.c index 672538ca9831..5fa9a8d8d865 100644 --- a/fs/super.c +++ b/fs/super.c @@ -37,6 +37,7 @@ #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); @@ -574,6 +575,28 @@ void drop_super_exclusive(struct super_block *sb) } EXPORT_SYMBOL(drop_super_exclusive); +static void __iterate_supers(void (*f)(struct super_block *)) +{ + struct super_block *sb, *p = NULL; + + spin_lock(&sb_lock); + list_for_each_entry(sb, &super_blocks, s_list) { + if (hlist_unhashed(&sb->s_instances)) + continue; + sb->s_count++; + spin_unlock(&sb_lock); + + f(sb); + + spin_lock(&sb_lock); + if (p) + __put_super(p); + p = sb; + } + if (p) + __put_super(p); + spin_unlock(&sb_lock); +} /** * iterate_supers - call function for all active superblocks * @f: function to call @@ -881,33 +904,22 @@ cancel_readonly: return retval; } -static void do_emergency_remount(struct work_struct *work) +static void do_emergency_remount_callback(struct super_block *sb) { - struct super_block *sb, *p = NULL; - - spin_lock(&sb_lock); - list_for_each_entry(sb, &super_blocks, s_list) { - if (hlist_unhashed(&sb->s_instances)) - continue; - sb->s_count++; - spin_unlock(&sb_lock); - down_write(&sb->s_umount); - if (sb->s_root && sb->s_bdev && (sb->s_flags & SB_BORN) && - !sb_rdonly(sb)) { - /* - * What lock protects sb->s_flags?? - */ - do_remount_sb(sb, SB_RDONLY, NULL, 1); - } - up_write(&sb->s_umount); - spin_lock(&sb_lock); - if (p) - __put_super(p); - p = sb; + down_write(&sb->s_umount); + if (sb->s_root && sb->s_bdev && (sb->s_flags & SB_BORN) && + !sb_rdonly(sb)) { + /* + * What lock protects sb->s_flags?? + */ + do_remount_sb(sb, SB_RDONLY, NULL, 1); } - if (p) - __put_super(p); - spin_unlock(&sb_lock); + up_write(&sb->s_umount); +} + +static void do_emergency_remount(struct work_struct *work) +{ + __iterate_supers(do_emergency_remount_callback); kfree(work); printk("Emergency Remount complete\n"); } @@ -923,6 +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 @@ -1492,11 +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; @@ -1527,4 +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); diff --git a/include/linux/fs.h b/include/linux/fs.h index 5d93995743b5..760d8da1b6c7 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -2445,6 +2445,7 @@ extern int sync_blockdev(struct block_device *bdev); extern void kill_bdev(struct block_device *); extern struct super_block *freeze_bdev(struct block_device *); extern void emergency_thaw_all(void); +extern void emergency_thaw_bdev(struct super_block *sb); extern int thaw_bdev(struct block_device *bdev, struct super_block *sb); extern int fsync_bdev(struct block_device *); @@ -2470,6 +2471,11 @@ static inline int thaw_bdev(struct block_device *bdev, struct super_block *sb) return 0; } +static inline int emergency_thaw_bdev(struct super_block *sb) +{ + return 0; +} + static inline void iterate_bdevs(void (*f)(struct block_device *, void *), void *arg) { } |