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Message-ID: <20140501231341.31890.18777.stgit@birch.djwong.org> Date: Thu, 01 May 2014 16:13:41 -0700 From: "Darrick J. Wong" <darrick.wong@...cle.com> To: tytso@....edu, darrick.wong@...cle.com Cc: linux-ext4@...r.kernel.org Subject: [PATCH 12/37] e2fsck: insert a missing dirent tail for checksums if possible If e2fsck is writing a block of directory entries to disk, it should adjust the dirents to add the dirent tail if one is missing. It's not a big deal if there's no space to do this since rehash (pass 3A) will reconstruct directories for us. However, we may as well avoid unnecessary work. Signed-off-by: Darrick J. Wong <darrick.wong@...cle.com> --- e2fsck/pass2.c | 40 ++++++++++++++++++++++++++++++++++++++++ 1 file changed, 40 insertions(+) diff --git a/e2fsck/pass2.c b/e2fsck/pass2.c index 5488c73..95f51b7 100644 --- a/e2fsck/pass2.c +++ b/e2fsck/pass2.c @@ -739,6 +739,41 @@ static int is_last_entry(ext2_filsys fs, int inline_data_size, return (offset < fs->blocksize - csum_size); } +static errcode_t insert_dirent_tail(ext2_filsys fs, void *dirbuf) +{ + struct ext2_dir_entry *d; + void *top; + struct ext2_dir_entry_tail *t; + unsigned int rec_len; + + d = dirbuf; + top = EXT2_DIRENT_TAIL(dirbuf, fs->blocksize); + + rec_len = d->rec_len; + while (rec_len && !(rec_len & 0x3)) { + d = (struct ext2_dir_entry *)(((char *)d) + rec_len); + if (((void *)d) + d->rec_len >= top) + break; + rec_len = d->rec_len; + } + + if (d != top) { + size_t min_size = EXT2_DIR_REC_LEN( + ext2fs_dirent_name_len(dirbuf)); + if (min_size > d->rec_len - sizeof(struct ext2_dir_entry_tail)) + return EXT2_ET_DIR_NO_SPACE_FOR_CSUM; + d->rec_len -= sizeof(struct ext2_dir_entry_tail); + } + + t = (struct ext2_dir_entry_tail *)top; + if (t->det_reserved_zero1 || + t->det_rec_len != sizeof(struct ext2_dir_entry_tail) || + t->det_reserved_name_len != EXT2_DIR_NAME_LEN_CSUM) + ext2fs_initialize_dirent_tail(fs, t); + + return 0; +} + static int check_dir_block(ext2_filsys fs, struct ext2_db_entry2 *db, void *priv_data) @@ -1275,8 +1310,13 @@ skip_checksum: if (EXT2_HAS_RO_COMPAT_FEATURE(fs->super, EXT4_FEATURE_RO_COMPAT_METADATA_CSUM) && is_leaf && + !inline_data_size && !ext2fs_dirent_has_tail(fs, (struct ext2_dir_entry *)buf)) + { + if (insert_dirent_tail(fs, buf) == 0) + goto write_and_fix; e2fsck_rehash_dir_later(ctx, ino); + } write_and_fix: if (e2fsck_dir_will_be_rehashed(ctx, ino)) -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@...r.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
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