From ad2c1604da74a3bbef96e7259e389ccba0cf613a Mon Sep 17 00:00:00 2001 From: Pekka Enberg Date: Sun, 30 Oct 2005 15:03:50 -0800 Subject: [PATCH] fat: Remove duplicate directory scanning code This patch removes duplicate directory scanning code from fs/fat/dir.c. The two functions that share identical code are fat_readdirx() and fat_search_long(). This patch also renames fat_readdirx to __fat_readdir(). Signed-off-by: Pekka Enberg Signed-off-by: OGAWA Hirofumi Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/fat/dir.c | 224 +++++++++++++++++++++++++++-------------------------------- 1 file changed, 101 insertions(+), 123 deletions(-) (limited to 'fs/fat') diff --git a/fs/fat/dir.c b/fs/fat/dir.c index 204d861..ba82496 100644 --- a/fs/fat/dir.c +++ b/fs/fat/dir.c @@ -222,6 +222,80 @@ fat_shortname2uni(struct nls_table *nls, unsigned char *buf, int buf_size, return len; } +enum { PARSE_INVALID = 1, PARSE_NOT_LONGNAME, PARSE_EOF, }; + +/** + * fat_parse_long - Parse extended directory entry. + * + * This function returns zero on success, negative value on error, or one of + * the following: + * + * %PARSE_INVALID - Directory entry is invalid. + * %PARSE_NOT_LONGNAME - Directory entry does not contain longname. + * %PARSE_EOF - Directory has no more entries. + */ +static int fat_parse_long(struct inode *dir, loff_t *pos, + struct buffer_head **bh, struct msdos_dir_entry **de, + wchar_t **unicode, unsigned char *nr_slots) +{ + struct msdos_dir_slot *ds; + unsigned char id, slot, slots, alias_checksum; + + if (!*unicode) { + *unicode = (wchar_t *)__get_free_page(GFP_KERNEL); + if (!*unicode) { + brelse(*bh); + return -ENOMEM; + } + } +parse_long: + slots = 0; + ds = (struct msdos_dir_slot *)*de; + id = ds->id; + if (!(id & 0x40)) + return PARSE_INVALID; + slots = id & ~0x40; + if (slots > 20 || !slots) /* ceil(256 * 2 / 26) */ + return PARSE_INVALID; + *nr_slots = slots; + alias_checksum = ds->alias_checksum; + + slot = slots; + while (1) { + int offset; + + slot--; + offset = slot * 13; + fat16_towchar(*unicode + offset, ds->name0_4, 5); + fat16_towchar(*unicode + offset + 5, ds->name5_10, 6); + fat16_towchar(*unicode + offset + 11, ds->name11_12, 2); + + if (ds->id & 0x40) + (*unicode)[offset + 13] = 0; + if (fat_get_entry(dir, pos, bh, de) < 0) + return PARSE_EOF; + if (slot == 0) + break; + ds = (struct msdos_dir_slot *)*de; + if (ds->attr != ATTR_EXT) + return PARSE_NOT_LONGNAME; + if ((ds->id & ~0x40) != slot) + goto parse_long; + if (ds->alias_checksum != alias_checksum) + goto parse_long; + } + if ((*de)->name[0] == DELETED_FLAG) + return PARSE_INVALID; + if ((*de)->attr == ATTR_EXT) + goto parse_long; + if (IS_FREE((*de)->name) || ((*de)->attr & ATTR_VOLUME)) + return PARSE_INVALID; + if (fat_checksum((*de)->name) != alias_checksum) + *nr_slots = 0; + + return 0; +} + /* * Return values: negative -> error, 0 -> not found, positive -> found, * value is the total amount of slots, including the shortname entry. @@ -259,65 +333,16 @@ parse_record: if (de->attr != ATTR_EXT && IS_FREE(de->name)) continue; if (de->attr == ATTR_EXT) { - struct msdos_dir_slot *ds; - unsigned char id; - unsigned char slot; - unsigned char slots; - unsigned char alias_checksum; - - if (!unicode) { - unicode = (wchar_t *) - __get_free_page(GFP_KERNEL); - if (!unicode) { - brelse(bh); - return -ENOMEM; - } - } -parse_long: - slots = 0; - ds = (struct msdos_dir_slot *) de; - id = ds->id; - if (!(id & 0x40)) - continue; - slots = id & ~0x40; - if (slots > 20 || !slots) /* ceil(256 * 2 / 26) */ - continue; - nr_slots = slots; - alias_checksum = ds->alias_checksum; - - slot = slots; - while (1) { - int offset; - - slot--; - offset = slot * 13; - fat16_towchar(unicode + offset, ds->name0_4, 5); - fat16_towchar(unicode + offset + 5, ds->name5_10, 6); - fat16_towchar(unicode + offset + 11, ds->name11_12, 2); - - if (ds->id & 0x40) { - unicode[offset + 13] = 0; - } - if (fat_get_entry(inode, &cpos, &bh, &de) < 0) - goto EODir; - if (slot == 0) - break; - ds = (struct msdos_dir_slot *) de; - if (ds->attr != ATTR_EXT) - goto parse_record; - if ((ds->id & ~0x40) != slot) - goto parse_long; - if (ds->alias_checksum != alias_checksum) - goto parse_long; - } - if (de->name[0] == DELETED_FLAG) - continue; - if (de->attr == ATTR_EXT) - goto parse_long; - if (IS_FREE(de->name) || (de->attr & ATTR_VOLUME)) + int status = fat_parse_long(inode, &cpos, &bh, &de, + &unicode, &nr_slots); + if (status < 0) + return status; + else if (status == PARSE_INVALID) continue; - if (fat_checksum(de->name) != alias_checksum) - nr_slots = 0; + else if (status == PARSE_NOT_LONGNAME) + goto parse_record; + else if (status == PARSE_EOF) + goto EODir; } memcpy(work, de->name, sizeof(de->name)); @@ -405,8 +430,8 @@ struct fat_ioctl_filldir_callback { int short_len; }; -static int fat_readdirx(struct inode *inode, struct file *filp, void *dirent, - filldir_t filldir, int short_only, int both) +static int __fat_readdir(struct inode *inode, struct file *filp, void *dirent, + filldir_t filldir, int short_only, int both) { struct super_block *sb = inode->i_sb; struct msdos_sb_info *sbi = MSDOS_SB(sb); @@ -455,9 +480,10 @@ static int fat_readdirx(struct inode *inode, struct file *filp, void *dirent, bh = NULL; GetNew: - long_slots = 0; if (fat_get_entry(inode, &cpos, &bh, &de) == -1) goto EODir; +parse_record: + long_slots = 0; /* Check for long filename entry */ if (isvfat) { if (de->name[0] == DELETED_FLAG) @@ -472,66 +498,18 @@ GetNew: } if (isvfat && de->attr == ATTR_EXT) { - struct msdos_dir_slot *ds; - unsigned char id; - unsigned char slot; - unsigned char slots; - unsigned char alias_checksum; - - if (!unicode) { - unicode = (wchar_t *)__get_free_page(GFP_KERNEL); - if (!unicode) { - filp->f_pos = cpos; - brelse(bh); - ret = -ENOMEM; - goto out; - } - } -ParseLong: - slots = 0; - ds = (struct msdos_dir_slot *) de; - id = ds->id; - if (!(id & 0x40)) - goto RecEnd; - slots = id & ~0x40; - if (slots > 20 || !slots) /* ceil(256 * 2 / 26) */ + int status = fat_parse_long(inode, &cpos, &bh, &de, + &unicode, &long_slots); + if (status < 0) { + filp->f_pos = cpos; + ret = status; + goto out; + } else if (status == PARSE_INVALID) goto RecEnd; - long_slots = slots; - alias_checksum = ds->alias_checksum; - - slot = slots; - while (1) { - int offset; - - slot--; - offset = slot * 13; - fat16_towchar(unicode + offset, ds->name0_4, 5); - fat16_towchar(unicode + offset + 5, ds->name5_10, 6); - fat16_towchar(unicode + offset + 11, ds->name11_12, 2); - - if (ds->id & 0x40) { - unicode[offset + 13] = 0; - } - if (fat_get_entry(inode, &cpos, &bh, &de) == -1) - goto EODir; - if (slot == 0) - break; - ds = (struct msdos_dir_slot *) de; - if (ds->attr != ATTR_EXT) - goto RecEnd; /* XXX */ - if ((ds->id & ~0x40) != slot) - goto ParseLong; - if (ds->alias_checksum != alias_checksum) - goto ParseLong; - } - if (de->name[0] == DELETED_FLAG) - goto RecEnd; - if (de->attr == ATTR_EXT) - goto ParseLong; - if (IS_FREE(de->name) || (de->attr & ATTR_VOLUME)) - goto RecEnd; - if (fat_checksum(de->name) != alias_checksum) - long_slots = 0; + else if (status == PARSE_NOT_LONGNAME) + goto parse_record; + else if (status == PARSE_EOF) + goto EODir; } if (sbi->options.dotsOK) { @@ -665,7 +643,7 @@ out: static int fat_readdir(struct file *filp, void *dirent, filldir_t filldir) { struct inode *inode = filp->f_dentry->d_inode; - return fat_readdirx(inode, filp, dirent, filldir, 0, 0); + return __fat_readdir(inode, filp, dirent, filldir, 0, 0); } static int fat_ioctl_filldir(void *__buf, const char *name, int name_len, @@ -754,8 +732,8 @@ static int fat_dir_ioctl(struct inode * inode, struct file * filp, down(&inode->i_sem); ret = -ENOENT; if (!IS_DEADDIR(inode)) { - ret = fat_readdirx(inode, filp, &buf, fat_ioctl_filldir, - short_only, both); + ret = __fat_readdir(inode, filp, &buf, fat_ioctl_filldir, + short_only, both); } up(&inode->i_sem); if (ret >= 0) -- cgit v1.1