From fa77dcfafeaa6bc73293c646bfc3d5192dcf0be2 Mon Sep 17 00:00:00 2001 From: "Darrick J. Wong" Date: Sun, 29 Apr 2012 18:35:10 -0400 Subject: ext4: calculate and verify block bitmap checksum Compute and verify the checksum of the block bitmap; this checksum is stored in the block group descriptor. Signed-off-by: Darrick J. Wong Signed-off-by: "Theodore Ts'o" --- fs/ext4/mballoc.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) (limited to 'fs/ext4/mballoc.c') diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c index 99ab428bcfa0..95a388fef397 100644 --- a/fs/ext4/mballoc.c +++ b/fs/ext4/mballoc.c @@ -788,7 +788,7 @@ static int ext4_mb_init_cache(struct page *page, char *incore) int first_block; struct super_block *sb; struct buffer_head *bhs; - struct buffer_head **bh; + struct buffer_head **bh = NULL; struct inode *inode; char *data; char *bitmap; @@ -2797,6 +2797,8 @@ ext4_mb_mark_diskspace_used(struct ext4_allocation_context *ac, } len = ext4_free_group_clusters(sb, gdp) - ac->ac_b_ex.fe_len; ext4_free_group_clusters_set(sb, gdp, len); + ext4_block_bitmap_csum_set(sb, ac->ac_b_ex.fe_group, gdp, bitmap_bh, + EXT4_BLOCKS_PER_GROUP(sb) / 8); gdp->bg_checksum = ext4_group_desc_csum(sbi, ac->ac_b_ex.fe_group, gdp); ext4_unlock_group(sb, ac->ac_b_ex.fe_group); @@ -4659,6 +4661,8 @@ do_more: ret = ext4_free_group_clusters(sb, gdp) + count_clusters; ext4_free_group_clusters_set(sb, gdp, ret); + ext4_block_bitmap_csum_set(sb, block_group, gdp, bitmap_bh, + EXT4_BLOCKS_PER_GROUP(sb) / 8); gdp->bg_checksum = ext4_group_desc_csum(sbi, block_group, gdp); ext4_unlock_group(sb, block_group); percpu_counter_add(&sbi->s_freeclusters_counter, count_clusters); @@ -4803,6 +4807,8 @@ int ext4_group_add_blocks(handle_t *handle, struct super_block *sb, mb_free_blocks(NULL, &e4b, bit, count); blk_free_count = blocks_freed + ext4_free_group_clusters(sb, desc); ext4_free_group_clusters_set(sb, desc, blk_free_count); + ext4_block_bitmap_csum_set(sb, block_group, desc, bitmap_bh, + EXT4_BLOCKS_PER_GROUP(sb) / 8); desc->bg_checksum = ext4_group_desc_csum(sbi, block_group, desc); ext4_unlock_group(sb, block_group); percpu_counter_add(&sbi->s_freeclusters_counter, -- cgit v1.2.3-59-g8ed1b From feb0ab32a57e4e6c8b24f6fb68f0ce08efe4603c Mon Sep 17 00:00:00 2001 From: "Darrick J. Wong" Date: Sun, 29 Apr 2012 18:45:10 -0400 Subject: ext4: make block group checksums use metadata_csum algorithm metadata_csum supersedes uninit_bg. Convert the ROCOMPAT uninit_bg flag check to a helper function that covers both, and make the checksum calculation algorithm use either crc16 or the metadata_csum chosen algorithm depending on which flag is set. Print a warning if we try to mount a filesystem with both feature flags set. Signed-off-by: Darrick J. Wong Signed-off-by: "Theodore Ts'o" --- fs/ext4/balloc.c | 4 +-- fs/ext4/ext4.h | 6 ++--- fs/ext4/ialloc.c | 17 +++++------- fs/ext4/inode.c | 3 +-- fs/ext4/mballoc.c | 6 ++--- fs/ext4/resize.c | 9 +++---- fs/ext4/super.c | 81 ++++++++++++++++++++++++++++++++++++++----------------- 7 files changed, 76 insertions(+), 50 deletions(-) (limited to 'fs/ext4/mballoc.c') diff --git a/fs/ext4/balloc.c b/fs/ext4/balloc.c index 0a64e4d5dbad..5745d53c67e8 100644 --- a/fs/ext4/balloc.c +++ b/fs/ext4/balloc.c @@ -168,7 +168,7 @@ void ext4_init_block_bitmap(struct super_block *sb, struct buffer_head *bh, /* If checksum is bad mark all blocks used to prevent allocation * essentially implementing a per-group read-only flag. */ - if (!ext4_group_desc_csum_verify(sbi, block_group, gdp)) { + if (!ext4_group_desc_csum_verify(sb, block_group, gdp)) { ext4_error(sb, "Checksum bad for group %u", block_group); ext4_free_group_clusters_set(sb, gdp, 0); ext4_free_inodes_set(sb, gdp, 0); @@ -214,7 +214,7 @@ void ext4_init_block_bitmap(struct super_block *sb, struct buffer_head *bh, sb->s_blocksize * 8, bh->b_data); ext4_block_bitmap_csum_set(sb, block_group, gdp, bh, EXT4_BLOCKS_PER_GROUP(sb) / 8); - gdp->bg_checksum = ext4_group_desc_csum(sbi, block_group, gdp); + ext4_group_desc_csum_set(sb, block_group, gdp); } /* Return the number of free blocks in a block group. It is used when diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h index 57d7c356eaab..84e76bb96070 100644 --- a/fs/ext4/ext4.h +++ b/fs/ext4/ext4.h @@ -2114,10 +2114,10 @@ extern void ext4_used_dirs_set(struct super_block *sb, struct ext4_group_desc *bg, __u32 count); extern void ext4_itable_unused_set(struct super_block *sb, struct ext4_group_desc *bg, __u32 count); -extern __le16 ext4_group_desc_csum(struct ext4_sb_info *sbi, __u32 group, - struct ext4_group_desc *gdp); -extern int ext4_group_desc_csum_verify(struct ext4_sb_info *sbi, __u32 group, +extern int ext4_group_desc_csum_verify(struct super_block *sb, __u32 group, struct ext4_group_desc *gdp); +extern void ext4_group_desc_csum_set(struct super_block *sb, __u32 group, + struct ext4_group_desc *gdp); static inline int ext4_has_group_desc_csum(struct super_block *sb) { diff --git a/fs/ext4/ialloc.c b/fs/ext4/ialloc.c index a6383fcb714b..a044a9b77491 100644 --- a/fs/ext4/ialloc.c +++ b/fs/ext4/ialloc.c @@ -70,13 +70,11 @@ static unsigned ext4_init_inode_bitmap(struct super_block *sb, ext4_group_t block_group, struct ext4_group_desc *gdp) { - struct ext4_sb_info *sbi = EXT4_SB(sb); - J_ASSERT_BH(bh, buffer_locked(bh)); /* If checksum is bad mark all blocks and inodes use to prevent * allocation, essentially implementing a per-group read-only flag. */ - if (!ext4_group_desc_csum_verify(sbi, block_group, gdp)) { + if (!ext4_group_desc_csum_verify(sb, block_group, gdp)) { ext4_error(sb, "Checksum bad for group %u", block_group); ext4_free_group_clusters_set(sb, gdp, 0); ext4_free_inodes_set(sb, gdp, 0); @@ -92,7 +90,7 @@ static unsigned ext4_init_inode_bitmap(struct super_block *sb, bh->b_data); ext4_inode_bitmap_csum_set(sb, block_group, gdp, bh, EXT4_INODES_PER_GROUP(sb) / 8); - gdp->bg_checksum = ext4_group_desc_csum(sbi, block_group, gdp); + ext4_group_desc_csum_set(sb, block_group, gdp); return EXT4_INODES_PER_GROUP(sb); } @@ -298,7 +296,7 @@ void ext4_free_inode(handle_t *handle, struct inode *inode) } ext4_inode_bitmap_csum_set(sb, block_group, gdp, bitmap_bh, EXT4_INODES_PER_GROUP(sb) / 8); - gdp->bg_checksum = ext4_group_desc_csum(sbi, block_group, gdp); + ext4_group_desc_csum_set(sb, block_group, gdp); ext4_unlock_group(sb, block_group); percpu_counter_inc(&sbi->s_freeinodes_counter); @@ -731,7 +729,7 @@ repeat_in_this_group: got: /* We may have to initialize the block bitmap if it isn't already */ - if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_GDT_CSUM) && + if (ext4_has_group_desc_csum(sb) && gdp->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT)) { struct buffer_head *block_bitmap_bh; @@ -757,8 +755,7 @@ got: block_bitmap_bh, EXT4_BLOCKS_PER_GROUP(sb) / 8); - gdp->bg_checksum = ext4_group_desc_csum(sbi, group, - gdp); + ext4_group_desc_csum_set(sb, group, gdp); } ext4_unlock_group(sb, group); @@ -811,7 +808,7 @@ got: if (ext4_has_group_desc_csum(sb)) { ext4_inode_bitmap_csum_set(sb, group, gdp, inode_bitmap_bh, EXT4_INODES_PER_GROUP(sb) / 8); - gdp->bg_checksum = ext4_group_desc_csum(sbi, group, gdp); + ext4_group_desc_csum_set(sb, group, gdp); ext4_unlock_group(sb, group); } @@ -1181,7 +1178,7 @@ int ext4_init_inode_table(struct super_block *sb, ext4_group_t group, skip_zeroout: ext4_lock_group(sb, group); gdp->bg_flags |= cpu_to_le16(EXT4_BG_INODE_ZEROED); - gdp->bg_checksum = ext4_group_desc_csum(sbi, group, gdp); + ext4_group_desc_csum_set(sb, group, gdp); ext4_unlock_group(sb, group); BUFFER_TRACE(group_desc_bh, diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c index 16a67359b4c7..7bccdf32a32c 100644 --- a/fs/ext4/inode.c +++ b/fs/ext4/inode.c @@ -3584,8 +3584,7 @@ make_io: b = table; end = b + EXT4_SB(sb)->s_inode_readahead_blks; num = EXT4_INODES_PER_GROUP(sb); - if (EXT4_HAS_RO_COMPAT_FEATURE(sb, - EXT4_FEATURE_RO_COMPAT_GDT_CSUM)) + if (ext4_has_group_desc_csum(sb)) num -= ext4_itable_unused_count(sb, gdp); table += num / inodes_per_block; if (end > table) diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c index 95a388fef397..ccb9c2f527d5 100644 --- a/fs/ext4/mballoc.c +++ b/fs/ext4/mballoc.c @@ -2799,7 +2799,7 @@ ext4_mb_mark_diskspace_used(struct ext4_allocation_context *ac, ext4_free_group_clusters_set(sb, gdp, len); ext4_block_bitmap_csum_set(sb, ac->ac_b_ex.fe_group, gdp, bitmap_bh, EXT4_BLOCKS_PER_GROUP(sb) / 8); - gdp->bg_checksum = ext4_group_desc_csum(sbi, ac->ac_b_ex.fe_group, gdp); + ext4_group_desc_csum_set(sb, ac->ac_b_ex.fe_group, gdp); ext4_unlock_group(sb, ac->ac_b_ex.fe_group); percpu_counter_sub(&sbi->s_freeclusters_counter, ac->ac_b_ex.fe_len); @@ -4663,7 +4663,7 @@ do_more: ext4_free_group_clusters_set(sb, gdp, ret); ext4_block_bitmap_csum_set(sb, block_group, gdp, bitmap_bh, EXT4_BLOCKS_PER_GROUP(sb) / 8); - gdp->bg_checksum = ext4_group_desc_csum(sbi, block_group, gdp); + ext4_group_desc_csum_set(sb, block_group, gdp); ext4_unlock_group(sb, block_group); percpu_counter_add(&sbi->s_freeclusters_counter, count_clusters); @@ -4809,7 +4809,7 @@ int ext4_group_add_blocks(handle_t *handle, struct super_block *sb, ext4_free_group_clusters_set(sb, desc, blk_free_count); ext4_block_bitmap_csum_set(sb, block_group, desc, bitmap_bh, EXT4_BLOCKS_PER_GROUP(sb) / 8); - desc->bg_checksum = ext4_group_desc_csum(sbi, block_group, desc); + ext4_group_desc_csum_set(sb, block_group, desc); ext4_unlock_group(sb, block_group); percpu_counter_add(&sbi->s_freeclusters_counter, EXT4_B2C(sbi, blocks_freed)); diff --git a/fs/ext4/resize.c b/fs/ext4/resize.c index dc597e066308..a58ce7c507ae 100644 --- a/fs/ext4/resize.c +++ b/fs/ext4/resize.c @@ -1160,7 +1160,7 @@ static int ext4_setup_new_descs(handle_t *handle, struct super_block *sb, EXT4_B2C(sbi, group_data->free_blocks_count)); ext4_free_inodes_set(sb, gdp, EXT4_INODES_PER_GROUP(sb)); gdp->bg_flags = cpu_to_le16(*bg_flags); - gdp->bg_checksum = ext4_group_desc_csum(sbi, group, gdp); + ext4_group_desc_csum_set(sb, group, gdp); err = ext4_handle_dirty_metadata(handle, NULL, gdb_bh); if (unlikely(err)) { @@ -1399,17 +1399,14 @@ static int ext4_setup_next_flex_gd(struct super_block *sb, (1 + ext4_bg_num_gdb(sb, group + i) + le16_to_cpu(es->s_reserved_gdt_blocks)) : 0; group_data[i].free_blocks_count = blocks_per_group - overhead; - if (EXT4_HAS_RO_COMPAT_FEATURE(sb, - EXT4_FEATURE_RO_COMPAT_GDT_CSUM)) + if (ext4_has_group_desc_csum(sb)) flex_gd->bg_flags[i] = EXT4_BG_BLOCK_UNINIT | EXT4_BG_INODE_UNINIT; else flex_gd->bg_flags[i] = EXT4_BG_INODE_ZEROED; } - if (last_group == n_group && - EXT4_HAS_RO_COMPAT_FEATURE(sb, - EXT4_FEATURE_RO_COMPAT_GDT_CSUM)) + if (last_group == n_group && ext4_has_group_desc_csum(sb)) /* We need to initialize block bitmap of last group. */ flex_gd->bg_flags[i - 1] &= ~EXT4_BG_BLOCK_UNINIT; diff --git a/fs/ext4/super.c b/fs/ext4/super.c index f80c7e612829..c18c5968cd96 100644 --- a/fs/ext4/super.c +++ b/fs/ext4/super.c @@ -1952,43 +1952,69 @@ failed: return 0; } -__le16 ext4_group_desc_csum(struct ext4_sb_info *sbi, __u32 block_group, - struct ext4_group_desc *gdp) +static __le16 ext4_group_desc_csum(struct ext4_sb_info *sbi, __u32 block_group, + struct ext4_group_desc *gdp) { + int offset; __u16 crc = 0; + __le32 le_group = cpu_to_le32(block_group); - if (sbi->s_es->s_feature_ro_compat & - cpu_to_le32(EXT4_FEATURE_RO_COMPAT_GDT_CSUM)) { - int offset = offsetof(struct ext4_group_desc, bg_checksum); - __le32 le_group = cpu_to_le32(block_group); - - crc = crc16(~0, sbi->s_es->s_uuid, sizeof(sbi->s_es->s_uuid)); - crc = crc16(crc, (__u8 *)&le_group, sizeof(le_group)); - crc = crc16(crc, (__u8 *)gdp, offset); - offset += sizeof(gdp->bg_checksum); /* skip checksum */ - /* for checksum of struct ext4_group_desc do the rest...*/ - if ((sbi->s_es->s_feature_incompat & - cpu_to_le32(EXT4_FEATURE_INCOMPAT_64BIT)) && - offset < le16_to_cpu(sbi->s_es->s_desc_size)) - crc = crc16(crc, (__u8 *)gdp + offset, - le16_to_cpu(sbi->s_es->s_desc_size) - - offset); + if ((sbi->s_es->s_feature_ro_compat & + cpu_to_le32(EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))) { + /* Use new metadata_csum algorithm */ + __u16 old_csum; + __u32 csum32; + + old_csum = gdp->bg_checksum; + gdp->bg_checksum = 0; + csum32 = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)&le_group, + sizeof(le_group)); + csum32 = ext4_chksum(sbi, csum32, (__u8 *)gdp, + sbi->s_desc_size); + gdp->bg_checksum = old_csum; + + crc = csum32 & 0xFFFF; + goto out; } + /* old crc16 code */ + offset = offsetof(struct ext4_group_desc, bg_checksum); + + crc = crc16(~0, sbi->s_es->s_uuid, sizeof(sbi->s_es->s_uuid)); + crc = crc16(crc, (__u8 *)&le_group, sizeof(le_group)); + crc = crc16(crc, (__u8 *)gdp, offset); + offset += sizeof(gdp->bg_checksum); /* skip checksum */ + /* for checksum of struct ext4_group_desc do the rest...*/ + if ((sbi->s_es->s_feature_incompat & + cpu_to_le32(EXT4_FEATURE_INCOMPAT_64BIT)) && + offset < le16_to_cpu(sbi->s_es->s_desc_size)) + crc = crc16(crc, (__u8 *)gdp + offset, + le16_to_cpu(sbi->s_es->s_desc_size) - + offset); + +out: return cpu_to_le16(crc); } -int ext4_group_desc_csum_verify(struct ext4_sb_info *sbi, __u32 block_group, +int ext4_group_desc_csum_verify(struct super_block *sb, __u32 block_group, struct ext4_group_desc *gdp) { - if ((sbi->s_es->s_feature_ro_compat & - cpu_to_le32(EXT4_FEATURE_RO_COMPAT_GDT_CSUM)) && - (gdp->bg_checksum != ext4_group_desc_csum(sbi, block_group, gdp))) + if (ext4_has_group_desc_csum(sb) && + (gdp->bg_checksum != ext4_group_desc_csum(EXT4_SB(sb), + block_group, gdp))) return 0; return 1; } +void ext4_group_desc_csum_set(struct super_block *sb, __u32 block_group, + struct ext4_group_desc *gdp) +{ + if (!ext4_has_group_desc_csum(sb)) + return; + gdp->bg_checksum = ext4_group_desc_csum(EXT4_SB(sb), block_group, gdp); +} + /* Called at mount-time, super-block is locked */ static int ext4_check_descriptors(struct super_block *sb, ext4_group_t *first_not_zeroed) @@ -2043,7 +2069,7 @@ static int ext4_check_descriptors(struct super_block *sb, return 0; } ext4_lock_group(sb, i); - if (!ext4_group_desc_csum_verify(sbi, i, gdp)) { + if (!ext4_group_desc_csum_verify(sb, i, gdp)) { ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: " "Checksum for group %u failed (%u!=%u)", i, le16_to_cpu(ext4_group_desc_csum(sbi, i, @@ -3069,6 +3095,13 @@ static int ext4_fill_super(struct super_block *sb, void *data, int silent) goto cantfind_ext4; sbi->s_kbytes_written = le64_to_cpu(es->s_kbytes_written); + /* Warn if metadata_csum and gdt_csum are both set. */ + if (EXT4_HAS_RO_COMPAT_FEATURE(sb, + EXT4_FEATURE_RO_COMPAT_METADATA_CSUM) && + EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_GDT_CSUM)) + ext4_warning(sb, KERN_INFO "metadata_csum and uninit_bg are " + "redundant flags; please run fsck."); + /* Check for a known checksum algorithm */ if (!ext4_verify_csum_type(sb, es)) { ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with " @@ -4400,7 +4433,7 @@ static int ext4_remount(struct super_block *sb, int *flags, char *data) struct ext4_group_desc *gdp = ext4_get_group_desc(sb, g, NULL); - if (!ext4_group_desc_csum_verify(sbi, g, gdp)) { + if (!ext4_group_desc_csum_verify(sb, g, gdp)) { ext4_msg(sb, KERN_ERR, "ext4_remount: Checksum for group %u failed (%u!=%u)", g, le16_to_cpu(ext4_group_desc_csum(sbi, g, gdp)), -- cgit v1.2.3-59-g8ed1b From 9d99012ff26380a09092a9fddbb6e5f996dc631f Mon Sep 17 00:00:00 2001 From: Akira Fujita Date: Mon, 28 May 2012 14:19:25 -0400 Subject: ext4: remove needs_recovery in ext4_mb_init() needs_recovery in ext4_mb_init() is not used, remove it. Signed-off-by: Akira Fujita Signed-off-by: "Theodore Ts'o" --- fs/ext4/ext4.h | 2 +- fs/ext4/mballoc.c | 2 +- fs/ext4/super.c | 2 +- 3 files changed, 3 insertions(+), 3 deletions(-) (limited to 'fs/ext4/mballoc.c') diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h index d1e2735ac22f..511011a1e85d 100644 --- a/fs/ext4/ext4.h +++ b/fs/ext4/ext4.h @@ -1948,7 +1948,7 @@ extern void ext4_end_bitmap_read(struct buffer_head *bh, int uptodate); /* mballoc.c */ extern long ext4_mb_stats; extern long ext4_mb_max_to_scan; -extern int ext4_mb_init(struct super_block *, int); +extern int ext4_mb_init(struct super_block *); extern int ext4_mb_release(struct super_block *); extern ext4_fsblk_t ext4_mb_new_blocks(handle_t *, struct ext4_allocation_request *, int *); diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c index ccb9c2f527d5..45cb31e8dd27 100644 --- a/fs/ext4/mballoc.c +++ b/fs/ext4/mballoc.c @@ -2375,7 +2375,7 @@ static int ext4_groupinfo_create_slab(size_t size) return 0; } -int ext4_mb_init(struct super_block *sb, int needs_recovery) +int ext4_mb_init(struct super_block *sb) { struct ext4_sb_info *sbi = EXT4_SB(sb); unsigned i, j; diff --git a/fs/ext4/super.c b/fs/ext4/super.c index d9466a508414..dbc9544c7087 100644 --- a/fs/ext4/super.c +++ b/fs/ext4/super.c @@ -3768,7 +3768,7 @@ no_journal: } ext4_ext_init(sb); - err = ext4_mb_init(sb, needs_recovery); + err = ext4_mb_init(sb); if (err) { ext4_msg(sb, KERN_ERR, "failed to initialize mballoc (%d)", err); -- cgit v1.2.3-59-g8ed1b From 400db9d30146dc062aaba97a6301b425eb6015bc Mon Sep 17 00:00:00 2001 From: Zheng Liu Date: Mon, 28 May 2012 17:53:53 -0400 Subject: ext4: cleanup in ext4_discard_allocated_blocks() remove 'len' variable in ext4_discard_allocated_blocks() because it is useless. Signed-off-by: Zheng Liu Signed-off-by: "Theodore Ts'o" --- fs/ext4/mballoc.c | 8 ++------ 1 file changed, 2 insertions(+), 6 deletions(-) (limited to 'fs/ext4/mballoc.c') diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c index 45cb31e8dd27..e4b4ac1ec684 100644 --- a/fs/ext4/mballoc.c +++ b/fs/ext4/mballoc.c @@ -3073,13 +3073,9 @@ static void ext4_mb_collect_stats(struct ext4_allocation_context *ac) static void ext4_discard_allocated_blocks(struct ext4_allocation_context *ac) { struct ext4_prealloc_space *pa = ac->ac_pa; - int len; - - if (pa && pa->pa_type == MB_INODE_PA) { - len = ac->ac_b_ex.fe_len; - pa->pa_free += len; - } + if (pa && pa->pa_type == MB_INODE_PA) + pa->pa_free += ac->ac_b_ex.fe_len; } /* -- cgit v1.2.3-59-g8ed1b From 02b7831019ea4e7994968c84b5826fa8b248ffc8 Mon Sep 17 00:00:00 2001 From: Salman Qazi Date: Thu, 31 May 2012 23:51:27 -0400 Subject: ext4: add ext4_mb_unload_buddy in the error path ext4_free_blocks fails to pair an ext4_mb_load_buddy with a matching ext4_mb_unload_buddy when it fails a memory allocation. Signed-off-by: Salman Qazi Signed-off-by: "Theodore Ts'o" Cc: stable@kernel.org --- fs/ext4/mballoc.c | 1 + 1 file changed, 1 insertion(+) (limited to 'fs/ext4/mballoc.c') diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c index e4b4ac1ec684..3d9277c48bc8 100644 --- a/fs/ext4/mballoc.c +++ b/fs/ext4/mballoc.c @@ -4634,6 +4634,7 @@ do_more: */ new_entry = kmem_cache_alloc(ext4_free_data_cachep, GFP_NOFS); if (!new_entry) { + ext4_mb_unload_buddy(&e4b); err = -ENOMEM; goto error_return; } -- cgit v1.2.3-59-g8ed1b From 95599968d19db175829fb580baa6b68939b320fb Mon Sep 17 00:00:00 2001 From: Salman Qazi Date: Thu, 31 May 2012 23:52:14 -0400 Subject: ext4: remove mb_groups before tearing down the buddy_cache We can't have references held on pages in the s_buddy_cache while we are trying to truncate its pages and put the inode. All the pages must be gone before we reach clear_inode. This can only be gauranteed if we can prevent new users from grabbing references to s_buddy_cache's pages. The original bug can be reproduced and the bug fix can be verified by: while true; do mount -t ext4 /dev/ram0 /export/hda3/ram0; \ umount /export/hda3/ram0; done & while true; do cat /proc/fs/ext4/ram0/mb_groups; done Signed-off-by: Salman Qazi Signed-off-by: "Theodore Ts'o" Cc: stable@kernel.org --- fs/ext4/mballoc.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) (limited to 'fs/ext4/mballoc.c') diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c index 3d9277c48bc8..1cd6994fc446 100644 --- a/fs/ext4/mballoc.c +++ b/fs/ext4/mballoc.c @@ -2517,6 +2517,9 @@ int ext4_mb_release(struct super_block *sb) struct ext4_sb_info *sbi = EXT4_SB(sb); struct kmem_cache *cachep = get_groupinfo_cache(sb->s_blocksize_bits); + if (sbi->s_proc) + remove_proc_entry("mb_groups", sbi->s_proc); + if (sbi->s_group_info) { for (i = 0; i < ngroups; i++) { grinfo = ext4_get_group_info(sb, i); @@ -2564,8 +2567,6 @@ int ext4_mb_release(struct super_block *sb) } free_percpu(sbi->s_locality_groups); - if (sbi->s_proc) - remove_proc_entry("mb_groups", sbi->s_proc); return 0; } -- cgit v1.2.3-59-g8ed1b