X-Git-Url: http://git.onelab.eu/?a=blobdiff_plain;f=fs%2Ffat%2Fdir.c;h=698b85bb1dd45855a709635eb6239a4c9bbef0d6;hb=43bc926fffd92024b46cafaf7350d669ba9ca884;hp=e5ae1b720dde8b42321235bbb2b3369e017e9d27;hpb=cee37fe97739d85991964371c1f3a745c00dd236;p=linux-2.6.git

diff --git a/fs/fat/dir.c b/fs/fat/dir.c
index e5ae1b720..698b85bb1 100644
--- a/fs/fat/dir.c
+++ b/fs/fat/dir.c
@@ -30,6 +30,29 @@ static inline loff_t fat_make_i_pos(struct super_block *sb,
 		| (de - (struct msdos_dir_entry *)bh->b_data);
 }
 
+static inline void fat_dir_readahead(struct inode *dir, sector_t iblock,
+				     sector_t phys)
+{
+	struct super_block *sb = dir->i_sb;
+	struct msdos_sb_info *sbi = MSDOS_SB(sb);
+	struct buffer_head *bh;
+	int sec;
+
+	/* This is not a first sector of cluster, or sec_per_clus == 1 */
+	if ((iblock & (sbi->sec_per_clus - 1)) || sbi->sec_per_clus == 1)
+		return;
+	/* root dir of FAT12/FAT16 */
+	if ((sbi->fat_bits != 32) && (dir->i_ino == MSDOS_ROOT_INO))
+		return;
+
+	bh = sb_find_get_block(sb, phys);
+	if (bh == NULL || !buffer_uptodate(bh)) {
+		for (sec = 0; sec < sbi->sec_per_clus; sec++)
+			sb_breadahead(sb, phys + sec);
+	}
+	brelse(bh);
+}
+
 /* Returns the inode number of the directory entry at offset pos. If bh is
    non-NULL, it is brelse'd before. Pos is incremented. The buffer header is
    returned in bh.
@@ -45,8 +68,8 @@ static int fat__get_entry(struct inode *dir, loff_t *pos,
 {
 	struct super_block *sb = dir->i_sb;
 	sector_t phys, iblock;
-	int offset;
-	int err;
+	unsigned long mapped_blocks;
+	int err, offset;
 
 next:
 	if (*bh)
@@ -54,10 +77,12 @@ next:
 
 	*bh = NULL;
 	iblock = *pos >> sb->s_blocksize_bits;
-	err = fat_bmap(dir, iblock, &phys);
+	err = fat_bmap(dir, iblock, &phys, &mapped_blocks);
 	if (err || !phys)
 		return -1;	/* beyond EOF or error */
 
+	fat_dir_readahead(dir, iblock, phys);
+
 	*bh = sb_bread(sb, phys);
 	if (*bh == NULL) {
 		printk(KERN_ERR "FAT: Directory bread(block %llu) failed\n",
@@ -89,7 +114,7 @@ static inline int fat_get_entry(struct inode *dir, loff_t *pos,
 }
 
 /*
- * Convert Unicode 16 to UTF8, translated Unicode, or ASCII.
+ * Convert Unicode 16 to UTF-8, translated Unicode, or ASCII.
  * If uni_xlate is enabled and we can't get a 1:1 conversion, use a
  * colon as an escape character since it is normally invalid on the vfat
  * filesystem. The following four characters are the hexadecimal digits
@@ -197,6 +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.
@@ -234,68 +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 sum;
-			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) */
+			int status = fat_parse_long(inode, &cpos, &bh, &de,
+						    &unicode, &nr_slots);
+			if (status < 0)
+				return status;
+			else if (status == PARSE_INVALID)
 				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))
-				continue;
-			for (sum = 0, i = 0; i < 11; i++)
-				sum = (((sum&1)<<7)|((sum&0xfe)>>1)) + de->name[i];
-			if (sum != 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));
@@ -371,7 +418,7 @@ EODir:
 	return err;
 }
 
-EXPORT_SYMBOL(fat_search_long);
+EXPORT_SYMBOL_GPL(fat_search_long);
 
 struct fat_ioctl_filldir_callback {
 	struct dirent __user *dirent;
@@ -383,8 +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);
@@ -433,9 +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)
@@ -450,69 +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 sum;
-		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;
-		for (sum = 0, i = 0; i < 11; i++)
-			sum = (((sum&1)<<7)|((sum&0xfe)>>1)) + de->name[i];
-		if (sum != 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) {
@@ -635,8 +632,7 @@ RecEnd:
 EODir:
 	filp->f_pos = cpos;
 FillFailed:
-	if (bh)
-		brelse(bh);
+	brelse(bh);
 	if (unicode)
 		free_page((unsigned long)unicode);
 out:
@@ -647,7 +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,
@@ -733,19 +729,19 @@ static int fat_dir_ioctl(struct inode * inode, struct file * filp,
 
 	buf.dirent = d1;
 	buf.result = 0;
-	down(&inode->i_sem);
+	mutex_lock(&inode->i_mutex);
 	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);
+	mutex_unlock(&inode->i_mutex);
 	if (ret >= 0)
 		ret = buf.result;
 	return ret;
 }
 
-struct file_operations fat_dir_operations = {
+const struct file_operations fat_dir_operations = {
 	.read		= generic_read_dir,
 	.readdir	= fat_readdir,
 	.ioctl		= fat_dir_ioctl,
@@ -784,7 +780,7 @@ int fat_get_dotdot_entry(struct inode *dir, struct buffer_head **bh,
 	return -ENOENT;
 }
 
-EXPORT_SYMBOL(fat_get_dotdot_entry);
+EXPORT_SYMBOL_GPL(fat_get_dotdot_entry);
 
 /* See if directory is empty */
 int fat_dir_empty(struct inode *dir)
@@ -807,7 +803,7 @@ int fat_dir_empty(struct inode *dir)
 	return result;
 }
 
-EXPORT_SYMBOL(fat_dir_empty);
+EXPORT_SYMBOL_GPL(fat_dir_empty);
 
 /*
  * fat_subdirs counts the number of sub-directories of dir. It can be run
@@ -853,7 +849,7 @@ int fat_scan(struct inode *dir, const unsigned char *name,
 	return -ENOENT;
 }
 
-EXPORT_SYMBOL(fat_scan);
+EXPORT_SYMBOL_GPL(fat_scan);
 
 static int __fat_remove_entries(struct inode *dir, loff_t pos, int nr_slots)
 {
@@ -940,7 +936,7 @@ int fat_remove_entries(struct inode *dir, struct fat_slot_info *sinfo)
 	return 0;
 }
 
-EXPORT_SYMBOL(fat_remove_entries);
+EXPORT_SYMBOL_GPL(fat_remove_entries);
 
 static int fat_zeroed_cluster(struct inode *dir, sector_t blknr, int nr_used,
 			      struct buffer_head **bhs, int nr_bhs)
@@ -1052,7 +1048,7 @@ error:
 	return err;
 }
 
-EXPORT_SYMBOL(fat_alloc_new_dir);
+EXPORT_SYMBOL_GPL(fat_alloc_new_dir);
 
 static int fat_add_new_entries(struct inode *dir, void *slots, int nr_slots,
 			       int *nr_cluster, struct msdos_dir_entry **de,
@@ -1268,4 +1264,4 @@ error_remove:
 	return err;
 }
 
-EXPORT_SYMBOL(fat_add_entries);
+EXPORT_SYMBOL_GPL(fat_add_entries);