[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 <penberg@cs.helsinki.fi> Signed-off-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This commit is contained in:
Pekka Enberg
Linus Torvalds
parent
9131dd4256
commit
ad2c1604da
1 changed files with 101 additions and 123 deletions
212
fs/fat/dir.c
212
fs/fat/dir.c
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@ -222,6 +222,80 @@ fat_shortname2uni(struct nls_table *nls, unsigned char *buf, int buf_size,
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return len;
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}
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enum { PARSE_INVALID = 1, PARSE_NOT_LONGNAME, PARSE_EOF, };
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/**
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* fat_parse_long - Parse extended directory entry.
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*
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* This function returns zero on success, negative value on error, or one of
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* the following:
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*
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* %PARSE_INVALID - Directory entry is invalid.
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* %PARSE_NOT_LONGNAME - Directory entry does not contain longname.
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* %PARSE_EOF - Directory has no more entries.
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*/
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static int fat_parse_long(struct inode *dir, loff_t *pos,
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struct buffer_head **bh, struct msdos_dir_entry **de,
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wchar_t **unicode, unsigned char *nr_slots)
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{
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struct msdos_dir_slot *ds;
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unsigned char id, slot, slots, alias_checksum;
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if (!*unicode) {
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*unicode = (wchar_t *)__get_free_page(GFP_KERNEL);
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if (!*unicode) {
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brelse(*bh);
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return -ENOMEM;
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}
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}
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parse_long:
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slots = 0;
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ds = (struct msdos_dir_slot *)*de;
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id = ds->id;
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if (!(id & 0x40))
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return PARSE_INVALID;
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slots = id & ~0x40;
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if (slots > 20 || !slots) /* ceil(256 * 2 / 26) */
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return PARSE_INVALID;
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*nr_slots = slots;
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alias_checksum = ds->alias_checksum;
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slot = slots;
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while (1) {
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int offset;
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slot--;
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offset = slot * 13;
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fat16_towchar(*unicode + offset, ds->name0_4, 5);
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fat16_towchar(*unicode + offset + 5, ds->name5_10, 6);
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fat16_towchar(*unicode + offset + 11, ds->name11_12, 2);
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if (ds->id & 0x40)
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(*unicode)[offset + 13] = 0;
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if (fat_get_entry(dir, pos, bh, de) < 0)
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return PARSE_EOF;
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if (slot == 0)
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break;
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ds = (struct msdos_dir_slot *)*de;
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if (ds->attr != ATTR_EXT)
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return PARSE_NOT_LONGNAME;
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if ((ds->id & ~0x40) != slot)
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goto parse_long;
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if (ds->alias_checksum != alias_checksum)
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goto parse_long;
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}
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if ((*de)->name[0] == DELETED_FLAG)
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return PARSE_INVALID;
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if ((*de)->attr == ATTR_EXT)
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goto parse_long;
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if (IS_FREE((*de)->name) || ((*de)->attr & ATTR_VOLUME))
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return PARSE_INVALID;
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if (fat_checksum((*de)->name) != alias_checksum)
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*nr_slots = 0;
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return 0;
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}
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/*
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* Return values: negative -> error, 0 -> not found, positive -> found,
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* value is the total amount of slots, including the shortname entry.
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@ -259,65 +333,16 @@ int fat_search_long(struct inode *inode, const unsigned char *name,
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if (de->attr != ATTR_EXT && IS_FREE(de->name))
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continue;
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if (de->attr == ATTR_EXT) {
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struct msdos_dir_slot *ds;
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unsigned char id;
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unsigned char slot;
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unsigned char slots;
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unsigned char alias_checksum;
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if (!unicode) {
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unicode = (wchar_t *)
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__get_free_page(GFP_KERNEL);
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if (!unicode) {
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brelse(bh);
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return -ENOMEM;
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}
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}
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parse_long:
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slots = 0;
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ds = (struct msdos_dir_slot *) de;
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id = ds->id;
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if (!(id & 0x40))
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int status = fat_parse_long(inode, &cpos, &bh, &de,
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&unicode, &nr_slots);
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if (status < 0)
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return status;
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else if (status == PARSE_INVALID)
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continue;
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slots = id & ~0x40;
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if (slots > 20 || !slots) /* ceil(256 * 2 / 26) */
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continue;
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nr_slots = slots;
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alias_checksum = ds->alias_checksum;
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slot = slots;
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while (1) {
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int offset;
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slot--;
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offset = slot * 13;
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fat16_towchar(unicode + offset, ds->name0_4, 5);
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fat16_towchar(unicode + offset + 5, ds->name5_10, 6);
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fat16_towchar(unicode + offset + 11, ds->name11_12, 2);
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if (ds->id & 0x40) {
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unicode[offset + 13] = 0;
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}
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if (fat_get_entry(inode, &cpos, &bh, &de) < 0)
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goto EODir;
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if (slot == 0)
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break;
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ds = (struct msdos_dir_slot *) de;
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if (ds->attr != ATTR_EXT)
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else if (status == PARSE_NOT_LONGNAME)
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goto parse_record;
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if ((ds->id & ~0x40) != slot)
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goto parse_long;
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if (ds->alias_checksum != alias_checksum)
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goto parse_long;
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}
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if (de->name[0] == DELETED_FLAG)
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continue;
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if (de->attr == ATTR_EXT)
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goto parse_long;
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if (IS_FREE(de->name) || (de->attr & ATTR_VOLUME))
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continue;
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if (fat_checksum(de->name) != alias_checksum)
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nr_slots = 0;
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else if (status == PARSE_EOF)
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goto EODir;
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}
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memcpy(work, de->name, sizeof(de->name));
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@ -405,7 +430,7 @@ struct fat_ioctl_filldir_callback {
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int short_len;
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};
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static int fat_readdirx(struct inode *inode, struct file *filp, void *dirent,
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static int __fat_readdir(struct inode *inode, struct file *filp, void *dirent,
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filldir_t filldir, int short_only, int both)
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{
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struct super_block *sb = inode->i_sb;
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@ -455,9 +480,10 @@ static int fat_readdirx(struct inode *inode, struct file *filp, void *dirent,
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bh = NULL;
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GetNew:
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long_slots = 0;
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if (fat_get_entry(inode, &cpos, &bh, &de) == -1)
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goto EODir;
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parse_record:
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long_slots = 0;
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/* Check for long filename entry */
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if (isvfat) {
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if (de->name[0] == DELETED_FLAG)
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@ -472,66 +498,18 @@ static int fat_readdirx(struct inode *inode, struct file *filp, void *dirent,
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}
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if (isvfat && de->attr == ATTR_EXT) {
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struct msdos_dir_slot *ds;
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unsigned char id;
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unsigned char slot;
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unsigned char slots;
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unsigned char alias_checksum;
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if (!unicode) {
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unicode = (wchar_t *)__get_free_page(GFP_KERNEL);
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if (!unicode) {
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int status = fat_parse_long(inode, &cpos, &bh, &de,
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&unicode, &long_slots);
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if (status < 0) {
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filp->f_pos = cpos;
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brelse(bh);
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ret = -ENOMEM;
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ret = status;
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goto out;
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}
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}
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ParseLong:
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slots = 0;
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ds = (struct msdos_dir_slot *) de;
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id = ds->id;
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if (!(id & 0x40))
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} else if (status == PARSE_INVALID)
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goto RecEnd;
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slots = id & ~0x40;
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if (slots > 20 || !slots) /* ceil(256 * 2 / 26) */
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goto RecEnd;
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long_slots = slots;
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alias_checksum = ds->alias_checksum;
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slot = slots;
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while (1) {
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int offset;
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slot--;
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offset = slot * 13;
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fat16_towchar(unicode + offset, ds->name0_4, 5);
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fat16_towchar(unicode + offset + 5, ds->name5_10, 6);
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fat16_towchar(unicode + offset + 11, ds->name11_12, 2);
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if (ds->id & 0x40) {
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unicode[offset + 13] = 0;
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}
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if (fat_get_entry(inode, &cpos, &bh, &de) == -1)
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else if (status == PARSE_NOT_LONGNAME)
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goto parse_record;
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else if (status == PARSE_EOF)
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goto EODir;
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if (slot == 0)
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break;
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ds = (struct msdos_dir_slot *) de;
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if (ds->attr != ATTR_EXT)
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goto RecEnd; /* XXX */
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if ((ds->id & ~0x40) != slot)
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goto ParseLong;
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if (ds->alias_checksum != alias_checksum)
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goto ParseLong;
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}
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if (de->name[0] == DELETED_FLAG)
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goto RecEnd;
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if (de->attr == ATTR_EXT)
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goto ParseLong;
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if (IS_FREE(de->name) || (de->attr & ATTR_VOLUME))
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goto RecEnd;
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if (fat_checksum(de->name) != alias_checksum)
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long_slots = 0;
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}
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if (sbi->options.dotsOK) {
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@ -665,7 +643,7 @@ static int fat_readdirx(struct inode *inode, struct file *filp, void *dirent,
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static int fat_readdir(struct file *filp, void *dirent, filldir_t filldir)
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{
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struct inode *inode = filp->f_dentry->d_inode;
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return fat_readdirx(inode, filp, dirent, filldir, 0, 0);
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return __fat_readdir(inode, filp, dirent, filldir, 0, 0);
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}
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static int fat_ioctl_filldir(void *__buf, const char *name, int name_len,
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@ -754,7 +732,7 @@ static int fat_dir_ioctl(struct inode * inode, struct file * filp,
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down(&inode->i_sem);
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ret = -ENOENT;
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if (!IS_DEADDIR(inode)) {
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ret = fat_readdirx(inode, filp, &buf, fat_ioctl_filldir,
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ret = __fat_readdir(inode, filp, &buf, fat_ioctl_filldir,
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short_only, both);
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}
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up(&inode->i_sem);
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