Messages in this thread Patch in this message | | | From | Nigel Cunningham <> | Subject | [ 10/23] [Suspend2] Add support for freezing filesystem bdevs. | Date | Thu, 26 Jan 2006 13:45:48 +1000 |
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Add support for freezing and thawing bdevs of filesystems. Filesystems are frozen in reverse order so that nested filesystems don't cause deadlocks.
Signed-off-by: Nigel Cunningham <nigel@suspend2.net>
kernel/power/process.c | 50 ++++++++++++++++++++++++++++++++++++++++++++++++ 1 files changed, 50 insertions(+), 0 deletions(-)
diff --git a/kernel/power/process.c b/kernel/power/process.c index 09fc9ca..0e377ed 100644 --- a/kernel/power/process.c +++ b/kernel/power/process.c @@ -48,6 +48,56 @@ DECLARE_COMPLETION(thaw); static atomic_t nr_frozen; +struct frozen_fs +{ + struct list_head fsb_list; + struct super_block *sb; +}; + +LIST_HEAD(frozen_fs_list); + +void freezer_make_fses_rw(void) +{ + struct frozen_fs *fs, *next_fs; + + list_for_each_entry_safe(fs, next_fs, &frozen_fs_list, fsb_list) { + thaw_bdev(fs->sb->s_bdev, fs->sb); + + list_del(&fs->fsb_list); + kfree(fs); + } +} + +/* + * Done after userspace is frozen, so there should be no danger of + * fses being unmounted while we're in here. + */ +int freezer_make_fses_ro(void) +{ + struct frozen_fs *fs; + struct super_block *sb; + + /* Generate the list */ + list_for_each_entry(sb, &super_blocks, s_list) { + if (!sb->s_root || !sb->s_bdev || + (sb->s_frozen == SB_FREEZE_TRANS) || + (sb->s_flags & MS_RDONLY)) + continue; + + fs = kmalloc(sizeof(struct frozen_fs), GFP_ATOMIC); + fs->sb = sb; + list_add_tail(&fs->fsb_list, &frozen_fs_list); + }; + + /* Do the freezing in reverse order so filesystems dependant + * upon others are frozen in the right order. (Eg loopback + * on ext3). */ + list_for_each_entry_reverse(fs, &frozen_fs_list, fsb_list) + freeze_bdev(fs->sb->s_bdev); + + return 0; +} + static inline int freezeable(struct task_struct * p) { if ((p == current) || -- Nigel Cunningham nigel at suspend2 dot net - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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