From 05c2c00f3769abb9e323fcaca70d2de0b48af7ba Mon Sep 17 00:00:00 2001 From: Jan Kara Date: Wed, 16 Dec 2020 11:18:39 +0100 Subject: ext4: protect superblock modifications with a buffer lock Protect all superblock modifications (including checksum computation) with a superblock buffer lock. That way we are sure computed checksum matches current superblock contents (a mismatch could cause checksum failures in nojournal mode or if an unjournalled superblock update races with a journalled one). Also we avoid modifying superblock contents while it is being written out (which can cause DIF/DIX failures if we are running in nojournal mode). Signed-off-by: Jan Kara Link: https://lore.kernel.org/r/20201216101844.22917-4-jack@suse.cz Signed-off-by: Theodore Ts'o --- fs/ext4/resize.c | 12 ++++++++++++ 1 file changed, 12 insertions(+) (limited to 'fs/ext4/resize.c') diff --git a/fs/ext4/resize.c b/fs/ext4/resize.c index 928700d57eb6..6155f2b9538c 100644 --- a/fs/ext4/resize.c +++ b/fs/ext4/resize.c @@ -899,7 +899,10 @@ static int add_new_gdb(handle_t *handle, struct inode *inode, EXT4_SB(sb)->s_gdb_count++; ext4_kvfree_array_rcu(o_group_desc); + lock_buffer(EXT4_SB(sb)->s_sbh); le16_add_cpu(&es->s_reserved_gdt_blocks, -1); + ext4_superblock_csum_set(sb); + unlock_buffer(EXT4_SB(sb)->s_sbh); err = ext4_handle_dirty_super(handle, sb); if (err) ext4_std_error(sb, err); @@ -1384,6 +1387,7 @@ static void ext4_update_super(struct super_block *sb, reserved_blocks *= blocks_count; do_div(reserved_blocks, 100); + lock_buffer(sbi->s_sbh); ext4_blocks_count_set(es, ext4_blocks_count(es) + blocks_count); ext4_free_blocks_count_set(es, ext4_free_blocks_count(es) + free_blocks); le32_add_cpu(&es->s_inodes_count, EXT4_INODES_PER_GROUP(sb) * @@ -1421,6 +1425,8 @@ static void ext4_update_super(struct super_block *sb, * active. */ ext4_r_blocks_count_set(es, ext4_r_blocks_count(es) + reserved_blocks); + ext4_superblock_csum_set(sb); + unlock_buffer(sbi->s_sbh); /* Update the free space counts */ percpu_counter_add(&sbi->s_freeclusters_counter, @@ -1717,8 +1723,11 @@ static int ext4_group_extend_no_check(struct super_block *sb, goto errout; } + lock_buffer(EXT4_SB(sb)->s_sbh); ext4_blocks_count_set(es, o_blocks_count + add); ext4_free_blocks_count_set(es, ext4_free_blocks_count(es) + add); + ext4_superblock_csum_set(sb); + unlock_buffer(EXT4_SB(sb)->s_sbh); ext4_debug("freeing blocks %llu through %llu\n", o_blocks_count, o_blocks_count + add); /* We add the blocks to the bitmap and set the group need init bit */ @@ -1874,10 +1883,13 @@ static int ext4_convert_meta_bg(struct super_block *sb, struct inode *inode) if (err) goto errout; + lock_buffer(sbi->s_sbh); ext4_clear_feature_resize_inode(sb); ext4_set_feature_meta_bg(sb); sbi->s_es->s_first_meta_bg = cpu_to_le32(num_desc_blocks(sb, sbi->s_groups_count)); + ext4_superblock_csum_set(sb); + unlock_buffer(sbi->s_sbh); err = ext4_handle_dirty_super(handle, sb); if (err) { -- cgit v1.2.3 From a3f5cf14ff917d46a4d491cf86210fd639d1ff38 Mon Sep 17 00:00:00 2001 From: Jan Kara Date: Wed, 16 Dec 2020 11:18:44 +0100 Subject: ext4: drop ext4_handle_dirty_super() The wrapper is now useless since it does what ext4_handle_dirty_metadata() does. Just remove it. Signed-off-by: Jan Kara Link: https://lore.kernel.org/r/20201216101844.22917-9-jack@suse.cz Signed-off-by: Theodore Ts'o --- fs/ext4/ext4_jbd2.c | 16 ---------------- fs/ext4/ext4_jbd2.h | 5 ----- fs/ext4/file.c | 2 +- fs/ext4/inode.c | 3 ++- fs/ext4/namei.c | 4 ++-- fs/ext4/resize.c | 8 ++++---- fs/ext4/xattr.c | 2 +- 7 files changed, 10 insertions(+), 30 deletions(-) (limited to 'fs/ext4/resize.c') diff --git a/fs/ext4/ext4_jbd2.c b/fs/ext4/ext4_jbd2.c index c7e410c4ab7d..be799040a415 100644 --- a/fs/ext4/ext4_jbd2.c +++ b/fs/ext4/ext4_jbd2.c @@ -372,19 +372,3 @@ int __ext4_handle_dirty_metadata(const char *where, unsigned int line, } return err; } - -int __ext4_handle_dirty_super(const char *where, unsigned int line, - handle_t *handle, struct super_block *sb) -{ - struct buffer_head *bh = EXT4_SB(sb)->s_sbh; - int err = 0; - - if (ext4_handle_valid(handle)) { - err = jbd2_journal_dirty_metadata(handle, bh); - if (err) - ext4_journal_abort_handle(where, line, __func__, - bh, handle, err); - } else - mark_buffer_dirty(bh); - return err; -} diff --git a/fs/ext4/ext4_jbd2.h b/fs/ext4/ext4_jbd2.h index a124c68b0c75..0d2fa423b7ad 100644 --- a/fs/ext4/ext4_jbd2.h +++ b/fs/ext4/ext4_jbd2.h @@ -244,9 +244,6 @@ int __ext4_handle_dirty_metadata(const char *where, unsigned int line, handle_t *handle, struct inode *inode, struct buffer_head *bh); -int __ext4_handle_dirty_super(const char *where, unsigned int line, - handle_t *handle, struct super_block *sb); - #define ext4_journal_get_write_access(handle, bh) \ __ext4_journal_get_write_access(__func__, __LINE__, (handle), (bh)) #define ext4_forget(handle, is_metadata, inode, bh, block_nr) \ @@ -257,8 +254,6 @@ int __ext4_handle_dirty_super(const char *where, unsigned int line, #define ext4_handle_dirty_metadata(handle, inode, bh) \ __ext4_handle_dirty_metadata(__func__, __LINE__, (handle), (inode), \ (bh)) -#define ext4_handle_dirty_super(handle, sb) \ - __ext4_handle_dirty_super(__func__, __LINE__, (handle), (sb)) handle_t *__ext4_journal_start_sb(struct super_block *sb, unsigned int line, int type, int blocks, int rsv_blocks, diff --git a/fs/ext4/file.c b/fs/ext4/file.c index 26907d5835d0..1cd3d26e3217 100644 --- a/fs/ext4/file.c +++ b/fs/ext4/file.c @@ -814,7 +814,7 @@ static int ext4_sample_last_mounted(struct super_block *sb, sizeof(sbi->s_es->s_last_mounted)); ext4_superblock_csum_set(sb); unlock_buffer(sbi->s_sbh); - ext4_handle_dirty_super(handle, sb); + ext4_handle_dirty_metadata(handle, NULL, sbi->s_sbh); out_journal: ext4_journal_stop(handle); out: diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c index 27de6f0a33c8..c173c8405856 100644 --- a/fs/ext4/inode.c +++ b/fs/ext4/inode.c @@ -5155,7 +5155,8 @@ static int ext4_do_update_inode(handle_t *handle, ext4_superblock_csum_set(sb); unlock_buffer(EXT4_SB(sb)->s_sbh); ext4_handle_sync(handle); - err = ext4_handle_dirty_super(handle, sb); + err = ext4_handle_dirty_metadata(handle, NULL, + EXT4_SB(sb)->s_sbh); } ext4_update_inode_fsync_trans(handle, inode, need_datasync); out_brelse: diff --git a/fs/ext4/namei.c b/fs/ext4/namei.c index 40970a509dcc..a3b28ef2455a 100644 --- a/fs/ext4/namei.c +++ b/fs/ext4/namei.c @@ -2988,7 +2988,7 @@ int ext4_orphan_add(handle_t *handle, struct inode *inode) mutex_unlock(&sbi->s_orphan_lock); if (dirty) { - err = ext4_handle_dirty_super(handle, sb); + err = ext4_handle_dirty_metadata(handle, NULL, sbi->s_sbh); rc = ext4_mark_iloc_dirty(handle, inode, &iloc); if (!err) err = rc; @@ -3069,7 +3069,7 @@ int ext4_orphan_del(handle_t *handle, struct inode *inode) ext4_superblock_csum_set(inode->i_sb); unlock_buffer(sbi->s_sbh); mutex_unlock(&sbi->s_orphan_lock); - err = ext4_handle_dirty_super(handle, inode->i_sb); + err = ext4_handle_dirty_metadata(handle, NULL, sbi->s_sbh); } else { struct ext4_iloc iloc2; struct inode *i_prev = diff --git a/fs/ext4/resize.c b/fs/ext4/resize.c index 6155f2b9538c..bd0d185654f3 100644 --- a/fs/ext4/resize.c +++ b/fs/ext4/resize.c @@ -903,7 +903,7 @@ static int add_new_gdb(handle_t *handle, struct inode *inode, le16_add_cpu(&es->s_reserved_gdt_blocks, -1); ext4_superblock_csum_set(sb); unlock_buffer(EXT4_SB(sb)->s_sbh); - err = ext4_handle_dirty_super(handle, sb); + err = ext4_handle_dirty_metadata(handle, NULL, EXT4_SB(sb)->s_sbh); if (err) ext4_std_error(sb, err); return err; @@ -1521,7 +1521,7 @@ static int ext4_flex_group_add(struct super_block *sb, ext4_update_super(sb, flex_gd); - err = ext4_handle_dirty_super(handle, sb); + err = ext4_handle_dirty_metadata(handle, NULL, sbi->s_sbh); exit_journal: err2 = ext4_journal_stop(handle); @@ -1734,7 +1734,7 @@ static int ext4_group_extend_no_check(struct super_block *sb, err = ext4_group_add_blocks(handle, sb, o_blocks_count, add); if (err) goto errout; - ext4_handle_dirty_super(handle, sb); + ext4_handle_dirty_metadata(handle, NULL, EXT4_SB(sb)->s_sbh); ext4_debug("freed blocks %llu through %llu\n", o_blocks_count, o_blocks_count + add); errout: @@ -1891,7 +1891,7 @@ static int ext4_convert_meta_bg(struct super_block *sb, struct inode *inode) ext4_superblock_csum_set(sb); unlock_buffer(sbi->s_sbh); - err = ext4_handle_dirty_super(handle, sb); + err = ext4_handle_dirty_metadata(handle, NULL, sbi->s_sbh); if (err) { ext4_std_error(sb, err); goto errout; diff --git a/fs/ext4/xattr.c b/fs/ext4/xattr.c index 1db7ca778d69..372208500f4e 100644 --- a/fs/ext4/xattr.c +++ b/fs/ext4/xattr.c @@ -796,7 +796,7 @@ static void ext4_xattr_update_super_block(handle_t *handle, ext4_set_feature_xattr(sb); ext4_superblock_csum_set(sb); unlock_buffer(EXT4_SB(sb)->s_sbh); - ext4_handle_dirty_super(handle, sb); + ext4_handle_dirty_metadata(handle, NULL, EXT4_SB(sb)->s_sbh); } } -- cgit v1.2.3