[PATCH 25/27] ext2: Implement freezing
From: Jan Kara <jack@suse.cz>
Date: 2012-06-01 22:31:37
Subsystem:
ext2 file system, filesystems (vfs and infrastructure), the rest · Maintainers:
Jan Kara, Alexander Viro, Christian Brauner, Linus Torvalds
The only missing piece to make freezing work reliably with ext2 is to stop iput() of unlinked inode from deleting the inode on frozen filesystem. So add a necessary protection to ext2_evict_inode(). We also provide appropriate ->freeze_fs and ->unfreeze_fs functions. Signed-off-by: Jan Kara <jack@suse.cz> --- fs/ext2/inode.c | 5 ++++- fs/ext2/super.c | 33 +++++++++++++++++++++++++++++++++ 2 files changed, 37 insertions(+), 1 deletions(-)
diff --git a/fs/ext2/inode.c b/fs/ext2/inode.c
index 264d315..6363ac6 100644
--- a/fs/ext2/inode.c
+++ b/fs/ext2/inode.c@@ -79,6 +79,7 @@ void ext2_evict_inode(struct inode * inode) truncate_inode_pages(&inode->i_data, 0); if (want_delete) { + sb_start_intwrite(inode->i_sb); /* set dtime */ EXT2_I(inode)->i_dtime = get_seconds(); mark_inode_dirty(inode);
@@ -98,8 +99,10 @@ void ext2_evict_inode(struct inode * inode) if (unlikely(rsv)) kfree(rsv); - if (want_delete) + if (want_delete) { ext2_free_inode(inode); + sb_end_intwrite(inode->i_sb); + } } typedef struct {
diff --git a/fs/ext2/super.c b/fs/ext2/super.c
index b3621cb..25232c1 100644
--- a/fs/ext2/super.c
+++ b/fs/ext2/super.c@@ -42,6 +42,8 @@ static void ext2_sync_super(struct super_block *sb, static int ext2_remount (struct super_block * sb, int * flags, char * data); static int ext2_statfs (struct dentry * dentry, struct kstatfs * buf); static int ext2_sync_fs(struct super_block *sb, int wait); +static int ext2_freeze(struct super_block *sb); +static int ext2_unfreeze(struct super_block *sb); void ext2_error(struct super_block *sb, const char *function, const char *fmt, ...)
@@ -305,6 +307,8 @@ static const struct super_operations ext2_sops = { .evict_inode = ext2_evict_inode, .put_super = ext2_put_super, .sync_fs = ext2_sync_fs, + .freeze_fs = ext2_freeze, + .unfreeze_fs = ext2_unfreeze, .statfs = ext2_statfs, .remount_fs = ext2_remount, .show_options = ext2_show_options,
@@ -1194,6 +1198,35 @@ static int ext2_sync_fs(struct super_block *sb, int wait) return 0; } +static int ext2_freeze(struct super_block *sb) +{ + struct ext2_sb_info *sbi = EXT2_SB(sb); + + /* + * Open but unlinked files present? Keep EXT2_VALID_FS flag cleared + * because we have unattached inodes and thus filesystem is not fully + * consistent. + */ + if (atomic_long_read(&sb->s_remove_count)) { + ext2_sync_fs(sb, 1); + return 0; + } + /* Set EXT2_FS_VALID flag */ + spin_lock(&sbi->s_lock); + sbi->s_es->s_state = cpu_to_le16(sbi->s_mount_state); + spin_unlock(&sbi->s_lock); + ext2_sync_super(sb, sbi->s_es, 1); + + return 0; +} + +static int ext2_unfreeze(struct super_block *sb) +{ + /* Just write sb to clear EXT2_VALID_FS flag */ + ext2_write_super(sb); + + return 0; +} void ext2_write_super(struct super_block *sb) {
--
1.7.1