[PATCH v2 02/13] ext2fs: Clean up directory entry handling APIs
From: Artem Blagodarenko <hidden>
Date: 2026-07-27 21:13:33
Subsystem:
library code, the rest · Maintainers:
Andrew Morton, Linus Torvalds
From: Artem Blagodarenko <redacted> Refactor directory entry manipulation code to use more appropriate macros and simplify API usage: - Replace EXT2_DIR_REC_LEN(namelen) with EXT2_DIR_NAME_LEN(namelen) to correctly calculate name length overhead instead of full record length - Rename EXT2_DIR_REC_LEN to EXT2_DIRENT_REC_LEN to show that it counts dirent. Pass directory entry structs directly to EXT2_DIRENT_REC_LEN() instead of extracting name_len field separately, leveraging helper function in macro - Use EXT2_FT_MASK constant instead of EXT2FS_LINK_FT_MASK for consistency with standard ext2fs conventions This improves code clarity and reduces API misuse by matching intent (calculating name space vs. total record space) with the appropriate macro. Signed-off-by: Andreas Dilger <redacted> Signed-off-by: Pravin Shelar <redacted> Signed-off-by: Artem Blagodarenko <redacted> Reviewed-by: Andreas Dilger <redacted> --- e2fsck/pass1.c | 2 +- e2fsck/pass2.c | 15 +++++++-------- lib/ext2fs/dirblock.c | 33 +++++++++++++++++++++++++++++++++ lib/ext2fs/ext2_fs.h | 17 ++++++++++++++++- lib/ext2fs/inline_data.c | 14 +++++++------- lib/ext2fs/link.c | 11 +++++------ lib/ext2fs/newdir.c | 4 ++-- 7 files changed, 71 insertions(+), 25 deletions(-)
diff --git a/e2fsck/pass1.c b/e2fsck/pass1.c
index fdde76cc2..39d1255f9 100644
--- a/e2fsck/pass1.c
+++ b/e2fsck/pass1.c@@ -770,7 +770,7 @@ static void check_is_really_dir(e2fsck_t ctx, struct problem_context *pctx, */ memcpy(&dotdot, inode->i_block, sizeof(dotdot)); memcpy(&de, ((char *)inode->i_block) + EXT4_INLINE_DATA_DOTDOT_SIZE, - EXT2_DIR_REC_LEN(0)); + EXT2_DIR_NAME_LEN(0)); dotdot = ext2fs_le32_to_cpu(dotdot); de.inode = ext2fs_le32_to_cpu(de.inode); de.rec_len = ext2fs_le16_to_cpu(de.rec_len);
diff --git a/e2fsck/pass2.c b/e2fsck/pass2.c
index 036c0022d..319e7e0e3 100644
--- a/e2fsck/pass2.c
+++ b/e2fsck/pass2.c@@ -862,11 +862,11 @@ static errcode_t insert_dirent_tail(ext2_filsys fs, void *dirbuf) d = dirbuf; top = EXT2_DIRENT_TAIL(dirbuf, fs->blocksize); - while (d->rec_len && !(d->rec_len & 0x3) && NEXT_DIRENT(d) <= top) - d = NEXT_DIRENT(d); + while (d->rec_len && !(d->rec_len & 0x3) && EXT2_NEXT_DIRENT(d) <= top) + d = EXT2_NEXT_DIRENT(d); if (d != top) { - unsigned int min_size = EXT2_DIR_REC_LEN( + unsigned int min_size = EXT2_DIR_NAME_LEN( ext2fs_dirent_name_len(dirbuf)); if (min_size > (char *)top - (char *)d) return EXT2_ET_DIR_NO_SPACE_FOR_CSUM;
@@ -881,7 +881,6 @@ static errcode_t insert_dirent_tail(ext2_filsys fs, void *dirbuf) return 0; } -#undef NEXT_DIRENT static errcode_t fix_inline_dir_size(e2fsck_t ctx, ext2_ino_t ino, size_t *inline_data_size,
@@ -900,7 +899,7 @@ static errcode_t fix_inline_dir_size(e2fsck_t ctx, ext2_ino_t ino, */ if (old_size > EXT4_MIN_INLINE_DATA_SIZE && old_size < EXT4_MIN_INLINE_DATA_SIZE + - EXT2_DIR_REC_LEN(1)) { + EXT2_DIR_NAME_LEN(1)) { old_size = EXT4_MIN_INLINE_DATA_SIZE; new_size = old_size; } else
@@ -1187,7 +1186,7 @@ inline_read_fail: if (((inline_data_size & 3) || (inline_data_size > EXT4_MIN_INLINE_DATA_SIZE && inline_data_size < EXT4_MIN_INLINE_DATA_SIZE + - EXT2_DIR_REC_LEN(1))) && + EXT2_DIR_NAME_LEN(1))) && fix_problem(ctx, PR_2_BAD_INLINE_DIR_SIZE, &pctx)) { errcode_t err = fix_inline_dir_size(ctx, ino, &inline_data_size, &pctx,
@@ -1409,7 +1408,7 @@ skip_checksum: memset(&dot, 0, sizeof(dot)); dirent = ˙ dirent->inode = ino; - dirent->rec_len = EXT2_DIR_REC_LEN(1); + dirent->rec_len = EXT2_DIR_NAME_LEN(1); dirent->name_len = 1 | filetype; dirent->name[0] = '.'; } else if (dot_state == 1) {
@@ -1417,7 +1416,7 @@ skip_checksum: dirent = &dotdot; dirent->inode = ((struct ext2_dir_entry *)buf)->inode; - dirent->rec_len = EXT2_DIR_REC_LEN(2); + dirent->rec_len = EXT2_DIR_NAME_LEN(2); dirent->name_len = 2 | filetype; dirent->name[0] = '.'; dirent->name[1] = '.';
diff --git a/lib/ext2fs/dirblock.c b/lib/ext2fs/dirblock.c
index 54b277728..d1d5a9e7f 100644
--- a/lib/ext2fs/dirblock.c
+++ b/lib/ext2fs/dirblock.c@@ -50,6 +50,39 @@ errcode_t ext2fs_read_dir_block3(ext2_filsys fs, blk64_t block, return ext2fs_read_dir_block4(fs, block, buf, flags, 0); } +/* + * Compute the dirdata length. This includes only optional extensions. + * Each extension has a bit set in the high 4 bits of + * de->file_type, and the extension length is the first byte in each entry. + */ +int ext2_get_dirdata_field_size(struct ext2_dir_entry *de, + __u8 dirdata_flags) +{ + char *lenp = de->name + (de->name_len & EXT2_NAME_LEN) + 1 /* NUL */; + __u8 extra_data_flags = (de->name_len & ~(EXT2_FT_MASK << 8)) >> 12; + int dlen = 0; + + dirdata_flags >>= 4; + while ((extra_data_flags & dirdata_flags) != 0) { + if (extra_data_flags & 1) { + if (dirdata_flags & 1) + dlen += *lenp; + + lenp += *lenp; + } + extra_data_flags >>= 1; + dirdata_flags >>= 1; + } + + /* add NUL terminator byte to dirdata length */ + return dlen + (dlen != 0); +} + +int ext2_get_dirdata_size(struct ext2_dir_entry *de) +{ + return ext2_get_dirdata_field_size(de, ~EXT2_FT_MASK); +} + errcode_t ext2fs_read_dir_block2(ext2_filsys fs, blk_t block, void *buf, int flags EXT2FS_ATTR((unused))) {
diff --git a/lib/ext2fs/ext2_fs.h b/lib/ext2fs/ext2_fs.h
index fcd420556..a4141eb71 100644
--- a/lib/ext2fs/ext2_fs.h
+++ b/lib/ext2fs/ext2_fs.h@@ -1091,6 +1091,10 @@ struct ext2_dir_entry_tail { #define EXT2_FT_SYMLINK 7 #define EXT2_FT_MAX 8 +#define EXT2_FT_MASK 0x0f +#if EXT4_FT_MAX > EXT4_FT_MASK +#error "conflicting EXT4_FT_MAX and EXT4_FT_MASK" +#endif /* * Annoyingly, e2fsprogs always swab16s ext2_dir_entry.name_len, so we
@@ -1100,6 +1104,9 @@ struct ext2_dir_entry_tail { */ #define EXT2_DIR_NAME_LEN_CSUM 0xDE00 +int ext2_get_dirdata_field_size(struct ext2_dir_entry *de, __u8 dirdata_flags); +int ext2_get_dirdata_size(struct ext2_dir_entry *de); + /* * EXT2_DIR_PAD defines the directory entries boundaries *
@@ -1109,7 +1116,13 @@ struct ext2_dir_entry_tail { #define EXT2_DIR_ENTRY_HASH_LEN 8 #define EXT2_DIR_PAD 4 #define EXT2_DIR_ROUND (EXT2_DIR_PAD - 1) -#define EXT2_DIR_REC_LEN(name_len) ext2fs_dir_rec_len(name_len, 0) +#define EXT2_DIR_NAME_LEN(name_len) (((name_len) + \ + EXT2_DIR_ENTRY_HEADER_LEN + \ + EXT2_DIR_ROUND) & \ + ~EXT2_DIR_ROUND) +#define EXT2_DIRENT_REC_LEN(de) (EXT2_DIR_NAME_LEN(((de)->name_len & \ + EXT2_NAME_LEN) + \ + ext2_get_dirdata_size(de))) static inline unsigned int ext2fs_dir_rec_len(__u8 name_len, int extended)
@@ -1202,4 +1215,6 @@ struct mmp_struct { #define EXT4_ENC_STRICT_MODE_FL (1 << 0) /* Reject invalid sequences */ +#define EXT2_NEXT_DIRENT(d) ((void *)((char *)(d) + (d)->rec_len)) + #endif /* _LINUX_EXT2_FS_H */
diff --git a/lib/ext2fs/inline_data.c b/lib/ext2fs/inline_data.c
index bd52e3770..c8d2fa0ce 100644
--- a/lib/ext2fs/inline_data.c
+++ b/lib/ext2fs/inline_data.c@@ -149,7 +149,7 @@ int ext2fs_inline_data_dir_iterate(ext2_filsys fs, ext2_ino_t ino, /* we first check '.' and '..' dir */ dirent.inode = ino; dirent.name_len = 1; - ext2fs_set_rec_len(fs, EXT2_DIR_REC_LEN(2), &dirent); + ext2fs_set_rec_len(fs, EXT2_DIR_NAME_LEN(2), &dirent); dirent.name[0] = '.'; dirent.name[1] = '\0'; ctx->buf = (char *)&dirent;
@@ -160,7 +160,7 @@ int ext2fs_inline_data_dir_iterate(ext2_filsys fs, ext2_ino_t ino, dirent.inode = ext2fs_le32_to_cpu(inode.i_block[0]); dirent.name_len = 2; - ext2fs_set_rec_len(fs, EXT2_DIR_REC_LEN(3), &dirent); + ext2fs_set_rec_len(fs, EXT2_DIR_NAME_LEN(3), &dirent); dirent.name[0] = '.'; dirent.name[1] = '.'; dirent.name[2] = '\0';
@@ -296,14 +296,14 @@ static errcode_t ext2fs_inline_data_convert_dir(ext2_filsys fs, ext2_ino_t ino, ext2fs_dirent_set_name_len(dir, 1); ext2fs_dirent_set_file_type(dir, filetype); dir->name[0] = '.'; - rec_len = (fs->blocksize - csum_size) - EXT2_DIR_REC_LEN(1); - dir->rec_len = EXT2_DIR_REC_LEN(1); + rec_len = (fs->blocksize - csum_size) - EXT2_DIR_NAME_LEN(1); + dir->rec_len = EXT2_DIR_NAME_LEN(1); /* * Set up entry for '..' */ dir = (struct ext2_dir_entry *) (bbuf + dir->rec_len); - dir->rec_len = EXT2_DIR_REC_LEN(2); + dir->rec_len = EXT2_DIR_NAME_LEN(2); dir->inode = ext2fs_le32_to_cpu(((__u32 *)ibuf)[0]); ext2fs_dirent_set_name_len(dir, 2); ext2fs_dirent_set_file_type(dir, filetype);
@@ -313,11 +313,11 @@ static errcode_t ext2fs_inline_data_convert_dir(ext2_filsys fs, ext2_ino_t ino, /* * Adjust the last rec_len */ - offset = EXT2_DIR_REC_LEN(1) + EXT2_DIR_REC_LEN(2); + offset = EXT2_DIR_NAME_LEN(1) + EXT2_DIR_NAME_LEN(2); dir = (struct ext2_dir_entry *) (bbuf + offset); memcpy(bbuf + offset, ibuf + EXT4_INLINE_DATA_DOTDOT_SIZE, size - EXT4_INLINE_DATA_DOTDOT_SIZE); - size += EXT2_DIR_REC_LEN(1) + EXT2_DIR_REC_LEN(2) - + size += EXT2_DIR_NAME_LEN(1) + EXT2_DIR_NAME_LEN(2) - EXT4_INLINE_DATA_DOTDOT_SIZE; do {
diff --git a/lib/ext2fs/link.c b/lib/ext2fs/link.c
index eccbf0d23..151274663 100644
--- a/lib/ext2fs/link.c
+++ b/lib/ext2fs/link.c@@ -197,7 +197,7 @@ static int link_proc(ext2_ino_t dir EXT2FS_ATTR((unused)), if (ls->done) return DIRENT_ABORT; - rec_len = EXT2_DIR_REC_LEN(ls->namelen); + rec_len = EXT2_DIR_NAME_LEN(ls->namelen); ls->err = ext2fs_get_rec_len(ls->fs, dirent, &curr_rec_len); if (ls->err)
@@ -226,7 +226,7 @@ static int link_proc(ext2_ino_t dir EXT2FS_ATTR((unused)), * truncate it and return. */ if (dirent->inode) { - min_rec_len = EXT2_DIR_REC_LEN(ext2fs_dirent_name_len(dirent)); + min_rec_len = EXT2_DIRENT_REC_LEN(dirent); if (curr_rec_len < (min_rec_len + rec_len)) return ret; rec_len = curr_rec_len - min_rec_len;
@@ -254,8 +254,7 @@ static int link_proc(ext2_ino_t dir EXT2FS_ATTR((unused)), ext2fs_dirent_set_name_len(dirent, ls->namelen); strncpy(dirent->name, ls->name, ls->namelen); if (ext2fs_has_feature_filetype(ls->sb)) - ext2fs_dirent_set_file_type(dirent, - ls->flags & EXT2FS_LINK_FT_MASK); + ext2fs_dirent_set_file_type(dirent, ls->flags & EXT2_FT_MASK); ls->done++; return DIRENT_ABORT|DIRENT_CHANGED;
@@ -331,8 +330,8 @@ static errcode_t dx_move_dirents(ext2_filsys fs, struct dx_hash_map *map, csum_size = sizeof(struct ext2_dir_entry_tail); for (i = 0; i < count; i++) { - de = (struct ext2_dir_entry *) ((char *)from + map[i].off); - rec_len = EXT2_DIR_REC_LEN(ext2fs_dirent_name_len(de)); + de = from + map[i].off; + rec_len = EXT2_DIRENT_REC_LEN(de); memcpy(to, de, rec_len); retval = ext2fs_set_rec_len(fs, rec_len, to); if (retval)
diff --git a/lib/ext2fs/newdir.c b/lib/ext2fs/newdir.c
index 7f4728500..f168d6686 100644
--- a/lib/ext2fs/newdir.c
+++ b/lib/ext2fs/newdir.c@@ -64,8 +64,8 @@ errcode_t ext2fs_new_dir_block(ext2_filsys fs, ext2_ino_t dir_ino, ext2fs_dirent_set_name_len(dir, 1); ext2fs_dirent_set_file_type(dir, filetype); dir->name[0] = '.'; - rec_len = (fs->blocksize - csum_size) - EXT2_DIR_REC_LEN(1); - dir->rec_len = EXT2_DIR_REC_LEN(1); + rec_len = (fs->blocksize - csum_size) - EXT2_DIR_NAME_LEN(1); + dir->rec_len = EXT2_DIR_NAME_LEN(1); /* * Set up entry for '..'
--
2.43.7