kernel.git/fs/ext4/migrate.c, branch linux-3.18.y

ext4: correctly migrate a file with a hole at the beginning

2015-08-04T18:14:59Z

[ Upstream commit 8974fec7d72e3e02752fe0f27b4c3719c78d9a15 ] Currently ext4_ind_migrate() doesn't correctly handle a file which contains a hole at the beginning of the file. This caused the migration to be done incorrectly, and then if there is a subsequent following delayed allocation write to the "hole", this would reclaim the same data blocks again and results in fs corruption. # assmuing 4k block size ext4, with delalloc enabled # skip the first block and write to the second block xfs_io -fc "pwrite 4k 4k" -c "fsync" /mnt/ext4/testfile # converting to indirect-mapped file, which would move the data blocks # to the beginning of the file, but extent status cache still marks # that region as a hole chattr -e /mnt/ext4/testfile # delayed allocation writes to the "hole", reclaim the same data block # again, results in i_blocks corruption xfs_io -c "pwrite 0 4k" /mnt/ext4/testfile umount /mnt/ext4 e2fsck -nf /dev/sda6 ... Inode 53, i_blocks is 16, should be 8. Fix? no ... Signed-off-by: Eryu Guan Signed-off-by: Theodore Ts'o Cc: stable@vger.kernel.org Signed-off-by: Sasha Levin

ext4: be more strict when migrating to non-extent based file

2015-08-04T18:14:41Z

[ Upstream commit d6f123a9297496ad0b6335fe881504c4b5b2a5e5 ] Currently the check in ext4_ind_migrate() is not enough before doing the real conversion: a) delayed allocated extents could bypass the check on eh->eh_entries and eh->eh_depth This can be demonstrated by this script xfs_io -fc "pwrite 0 4k" -c "pwrite 8k 4k" /mnt/ext4/testfile chattr -e /mnt/ext4/testfile where testfile has two extents but still be converted to non-extent based file format. b) only extent length is checked but not the offset, which would result in data lose (delalloc) or fs corruption (nodelalloc), because non-extent based file only supports at most (12 + 2^10 + 2^20 + 2^30) blocks This can be demostrated by xfs_io -fc "pwrite 5T 4k" /mnt/ext4/testfile chattr -e /mnt/ext4/testfile sync If delalloc is enabled, dmesg prints EXT4-fs warning (device dm-4): ext4_block_to_path:105: block 1342177280 > max in inode 53 EXT4-fs (dm-4): Delayed block allocation failed for inode 53 at logical offset 1342177280 with max blocks 1 with error 5 EXT4-fs (dm-4): This should not happen!! Data will be lost If delalloc is disabled, e2fsck -nf shows corruption Inode 53, i_size is 5497558142976, should be 4096. Fix? no Fix the two issues by a) forcing all delayed allocation blocks to be allocated before checking eh->eh_depth and eh->eh_entries b) limiting the last logical block of the extent is within direct map Signed-off-by: Eryu Guan Signed-off-by: Theodore Ts'o Cc: stable@vger.kernel.org Signed-off-by: Sasha Levin

ext4: rename ext4_ext_find_extent() to ext4_find_extent()

2014-09-01T18:43:09Z

Make the function name less redundant. Signed-off-by: Theodore Ts'o

ext4: allow a NULL argument to ext4_ext_drop_refs()

2014-09-01T18:39:09Z

Teach ext4_ext_drop_refs() to accept a NULL argument, much like kfree(). This allows us to drop a lot of checks to make sure path is non-NULL before calling ext4_ext_drop_refs(). Signed-off-by: Theodore Ts'o

ext4: drop EXT4_EX_NOFREE_ON_ERR from rest of extents handling code

2014-09-01T18:37:09Z

Drop EXT4_EX_NOFREE_ON_ERR from ext4_ext_create_new_leaf(), ext4_split_extent(), ext4_convert_unwritten_extents_endio(). This requires fixing all of their callers to potentially ext4_ext_find_extent() to free the struct ext4_ext_path object in case of an error, and there are interlocking dependencies all the way up to ext4_ext_map_blocks(), ext4_swap_extents(), and ext4_ext_remove_space(). Once this is done, we can drop the EXT4_EX_NOFREE_ON_ERR flag since it is no longer necessary. Signed-off-by: Theodore Ts'o

ext4: add i_data_sem sanity check

2014-07-28T02:28:15Z

Each caller of ext4_ext_dirty must hold i_data_sem, The only exception is migration code, let's make it convenient. Signed-off-by: Dmitry Monakhov Signed-off-by: Theodore Ts'o Reviewed-by: Jan Kara

ext4: remove unnecessary double parentheses

2014-05-12T16:55:07Z

Signed-off-by: Lukas Czerner Signed-off-by: "Theodore Ts'o"

ext4: Fix misspellings using 'codespell' tool

2013-08-28T18:40:12Z

Signed-off-by: Anatol Pomozov Signed-off-by: "Theodore Ts'o"

ext4: cache all of an extent tree's leaf block upon reading

2013-08-17T01:23:41Z

When we read in an extent tree leaf block from disk, arrange to have all of its entries cached. In nearly all cases the in-memory representation will be more compact than the on-disk representation in the buffer cache, and it allows us to get the information without having to traverse the extent tree for successive extents. Signed-off-by: "Theodore Ts'o" Reviewed-by: Zheng Liu

ext4: do not convert to indirect with bigalloc enabled

2013-04-11T14:54:46Z

With bigalloc feature enabled we do not support indirect addressing at all so we have to prevent extent addressing to indirect addressing conversion in this case. The problem has been introduced with the commit "ext4: support simple conversion of extent-mapped inodes to use i_blocks" Signed-off-by: Lukas Czerner Signed-off-by: "Theodore Ts'o"