Third round, change squashfs_read_metadata to return negative errors.

9 files changed, 117 insertions, 65 deletions

diff --git a/kernel/fs/squashfs/cache.c b/kernel/fs/squashfs/cache.c
index 82b6bbb..52032af 100644
--- a/kernel/fs/squashfs/cache.c
+++ b/kernel/fs/squashfs/cache.c
@@ -264,8 +264,11 @@ int squashfs_read_metadata(struct super_block *s, void *buffer,
 		entry = squashfs_cache_get(s, msblk->block_cache, *block, 0);
 		bytes = entry->length - *offset;
 
-		if (entry->error || bytes < 1) {
-			return_length = 0;
+		if (entry->error) {
+			return_length = entry->error;
+			goto finish;
+		} else if (bytes < 1) {
+			return_length = -EIO;
 			goto finish;
 		} else if (bytes >= length) {
 			if (buffer)
diff --git a/kernel/fs/squashfs/dir.c b/kernel/fs/squashfs/dir.c
index 99229a1..740800a 100644
--- a/kernel/fs/squashfs/dir.c
+++ b/kernel/fs/squashfs/dir.c
@@ -44,6 +44,10 @@ static const unsigned char squashfs_filetype_table[] = {
 /*
  * Lookup offset (f_pos) in the directory index, returning the
  * metadata block containing it.
+ *
+ * If we get an error reading the index then return the part of the index
+ * (if any) we have managed to read - the index isn't essential, just
+ * quicker.
  */
 static int get_dir_index_using_offset(struct super_block *s,
 	long long *next_block, unsigned int *next_offset,
@@ -51,7 +55,7 @@ static int get_dir_index_using_offset(struct super_block *s,
 	long long f_pos)
 {
 	struct squashfs_sb_info *msblk = s->s_fs_info;
-	int i, index, length = 0;
+	int err, i, index, length = 0;
 	struct squashfs_dir_index dir_index;
 
 	TRACE("Entered get_dir_index_using_offset, i_count %d, f_pos %lld\n",
@@ -67,15 +71,22 @@ static int get_dir_index_using_offset(struct super_block *s,
 		goto finish;
 
 	for (i = 0; i < i_count; i++) {
-		squashfs_read_metadata(s, &dir_index, &index_start,
-					&index_offset, sizeof(dir_index));
+		err = squashfs_read_metadata(s, &dir_index, &index_start,
+				&index_offset, sizeof(dir_index));
+		if (err < 0)
+			break;
 
 		index = le32_to_cpu(dir_index.index);
 		if (index > f_pos)
+			/*
+			 * Found the index we're looking for.
+			 */
 			break;
 
-		squashfs_read_metadata(s, NULL, &index_start, &index_offset,
-					le32_to_cpu(dir_index.size) + 1);
+		err = squashfs_read_metadata(s, NULL, &index_start,
+				&index_offset, le32_to_cpu(dir_index.size) + 1);
+		if (err < 0)
+			break;
 
 		length = index;
 		*next_block = le32_to_cpu(dir_index.start_block) +
@@ -99,7 +110,7 @@ static int squashfs_readdir(struct file *file, void *dirent, filldir_t filldir)
 	long long next_block = SQUASHFS_I(i)->start_block +
 				msblk->directory_table_start;
 	int next_offset = SQUASHFS_I(i)->offset, length = 0, dir_count, size,
-				type;
+				type, err;
 	unsigned int inode_number;
 	struct squashfs_dir_header dirh;
 	struct squashfs_dir_entry *dire;
@@ -157,8 +168,9 @@ static int squashfs_readdir(struct file *file, void *dirent, filldir_t filldir)
 		/*
 		 * Read directory header
 		 */
-		if (!squashfs_read_metadata(i->i_sb, &dirh, &next_block,
-					&next_offset, sizeof(dirh)))
+		err = squashfs_read_metadata(i->i_sb, &dirh, &next_block,
+					&next_offset, sizeof(dirh));
+		if (err < 0)
 			goto failed_read;
 
 		length += sizeof(dirh);
@@ -168,14 +180,16 @@ static int squashfs_readdir(struct file *file, void *dirent, filldir_t filldir)
 			/*
 			 * Read directory entry.
 			 */
-			if (!squashfs_read_metadata(i->i_sb, dire, &next_block,
-					&next_offset, sizeof(*dire)))
+			err = squashfs_read_metadata(i->i_sb, dire, &next_block,
+					&next_offset, sizeof(*dire));
+			if (err < 0)
 				goto failed_read;
 
 			size = le16_to_cpu(dire->size) + 1;
 
-			if (!squashfs_read_metadata(i->i_sb, dire->name,
-					&next_block, &next_offset, size))
+			err = squashfs_read_metadata(i->i_sb, dire->name,
+					&next_block, &next_offset, size);
+			if (err < 0)
 				goto failed_read;
 
 			length += sizeof(*dire) + size;
diff --git a/kernel/fs/squashfs/export.c b/kernel/fs/squashfs/export.c
index f7c089c..35c4cfc 100644
--- a/kernel/fs/squashfs/export.c
+++ b/kernel/fs/squashfs/export.c
@@ -56,11 +56,13 @@ static long long squashfs_inode_lookup(struct super_block *s, int ino)
 	int offset = SQUASHFS_LOOKUP_BLOCK_OFFSET(ino - 1);
 	long long start = le64_to_cpu(msblk->inode_lookup_table[blk]);
 	__le64 inode;
+	int err;
 
 	TRACE("Entered squashfs_inode_lookup, inode_number = %d\n", ino);
 
-	if (!squashfs_read_metadata(s, &inode, &start, &offset, sizeof(inode)))
-		return SQUASHFS_INVALID_BLK;
+	err = squashfs_read_metadata(s, &inode, &start, &offset, sizeof(inode));
+	if (err < 0)
+		return err;
 
 	TRACE("squashfs_inode_lookup, inode = 0x%llx\n", le64_to_cpu(inode));
 	return le64_to_cpu(inode);
@@ -76,7 +78,7 @@ static struct dentry *squashfs_export_iget(struct super_block *s,
 	TRACE("Entered squashfs_export_iget\n");
 
 	inode = squashfs_inode_lookup(s, inode_number);
-	if (inode != SQUASHFS_INVALID_BLK)
+	if (inode >= 0)
 		dentry = d_obtain_alias(squashfs_iget(s, inode, inode_number));
 
 	return dentry;
diff --git a/kernel/fs/squashfs/file.c b/kernel/fs/squashfs/file.c
index 162e708..f398e85 100644
--- a/kernel/fs/squashfs/file.c
+++ b/kernel/fs/squashfs/file.c
@@ -174,21 +174,22 @@ static void release_meta_index(struct inode *inode, struct meta_index *meta)
 static long long read_indexes(struct super_block *s, int n,
 				long long *start_block, int *offset)
 {
-	int i;
+	int err, i;
 	long long block = 0;
 	__le32 *blist = kmalloc(PAGE_CACHE_SIZE, GFP_KERNEL);
 
 	if (blist == NULL) {
 		ERROR("read_indexes: Failed to allocate block_list\n");
+		err = -ENOMEM;
 		goto failure;
 	}
 
 	while (n) {
 		int blocks = min_t(int, n, PAGE_CACHE_SIZE >> 2);
-		int res = squashfs_read_metadata(s, blist, start_block,
-				offset, blocks << 2);
 
-		if (res == 0) {
+		err = squashfs_read_metadata(s, blist, start_block,
+				offset, blocks << 2);
+		if (err < 0) {
 			ERROR("read_indexes: reading block [%llx:%x]\n",
 				*start_block, *offset);
 			goto failure;
@@ -206,7 +207,7 @@ static long long read_indexes(struct super_block *s, int n,
 
 failure:
 	kfree(blist);
-	return -1;
+	return err;
 }
 
 
@@ -246,7 +247,7 @@ static int fill_meta_index(struct inode *inode, int index,
 	long long cur_index_block = SQUASHFS_I(inode)->block_list_start;
 	int cur_offset = SQUASHFS_I(inode)->offset;
 	long long cur_data_block = SQUASHFS_I(inode)->start_block;
-	int i;
+	int err, i;
 
 	/*
 	 * Scale index to cache index (cache slot entry)
@@ -261,8 +262,6 @@ static int fill_meta_index(struct inode *inode, int index,
 			if (meta == NULL)
 				goto all_done;
 		} else {
-			if (meta->entries == 0)
-				goto failed;
 			offset = index < meta->offset + meta->entries ? index :
 				meta->offset + meta->entries - 1;
 			meta_entry = &meta->meta_entry[offset - meta->offset];
@@ -289,8 +288,16 @@ static int fill_meta_index(struct inode *inode, int index,
 			long long res = read_indexes(inode->i_sb, blocks,
 					&cur_index_block, &cur_offset);
 
-			if (res == -1)
+			if (res < 0) {
+				if (meta->entries == 0)
+					/*
+ 					 * Don't leave an empty slot on read
+ 					 * error allocated to this inode...
+ 					 */
+					meta->inode_number = 0;
+					err = res;
 				goto failed;
+			}
 
 			cur_data_block += res;
 			meta_entry = &meta->meta_entry[i - meta->offset];
@@ -320,7 +327,7 @@ all_done:
 
 failed:
 	release_meta_index(inode, meta);
-	return -1;
+	return err;
 }
 
 
@@ -331,7 +338,7 @@ failed:
 static long long read_blocklist(struct inode *inode, int index,
 				unsigned int *bsize)
 {
-	long long start, block, blks;
+	long long start, block = 0, blks;
 	int offset;
 	__le32 size;
 	int res = fill_meta_index(inode, index, &start, &offset, &block);
@@ -340,7 +347,7 @@ static long long read_blocklist(struct inode *inode, int index,
 		       " 0x%x, block 0x%llx\n", res, index, start, offset,
 			block);
 
-	if (res == -1)
+	if (res < 0)
 		goto failure;
 
 	/*
@@ -351,8 +358,10 @@ static long long read_blocklist(struct inode *inode, int index,
 	 */
 	if (res < index) {
 		blks = read_indexes(inode->i_sb, index - res, &start, &offset);
-		if (blks == -1)
+		if (blks < 0) {
+			res = blks;
 			goto failure;
+		}
 		block += blks;
 	}
 
@@ -361,14 +370,14 @@ static long long read_blocklist(struct inode *inode, int index,
 	 */
 	res = squashfs_read_metadata(inode->i_sb, &size, &start, &offset,
 			sizeof(size));
-	if (res == 0)
+	if (res < 0)
 		goto failure;
 	*bsize = le32_to_cpu(size);
 
 	return block;
 
 failure:
-	return -1;
+	return res;
 }
 
 
@@ -377,7 +386,7 @@ static int squashfs_readpage(struct file *file, struct page *page)
 	struct inode *inode = page->mapping->host;
 	struct squashfs_sb_info *msblk = inode->i_sb->s_fs_info;
 	long long block;
-	unsigned int bsize, i;
+	unsigned int bsize = 0, i;
 	int bytes, index = page->index >> (msblk->block_log - PAGE_CACHE_SHIFT);
 	struct squashfs_cache_entry *fragment = NULL;
 	void *pageaddr, *data_ptr = msblk->read_page;
@@ -402,7 +411,7 @@ static int squashfs_readpage(struct file *file, struct page *page)
 		 * to get location and block size.
 		 */
 		block = read_blocklist(inode, index, &bsize);
-		if (block == -1)
+		if (block < 0)
 			goto error_out;
 
 		if (bsize == 0) { /* hole */
diff --git a/kernel/fs/squashfs/fragment.c b/kernel/fs/squashfs/fragment.c
index 09abcb8..af1e37f 100644
--- a/kernel/fs/squashfs/fragment.c
+++ b/kernel/fs/squashfs/fragment.c
@@ -51,10 +51,11 @@ int get_fragment_location(struct super_block *s, unsigned int fragment,
 	int offset = SQUASHFS_FRAGMENT_INDEX_OFFSET(fragment);
 	long long start_block = le64_to_cpu(msblk->fragment_index[block]);
 	struct squashfs_fragment_entry fragment_entry;
-	int size = -EIO;
+	int size;
 
-	if (!squashfs_read_metadata(s, &fragment_entry, &start_block, &offset,
-				 		sizeof(fragment_entry)))
+	size = squashfs_read_metadata(s, &fragment_entry, &start_block, &offset,
+				 		sizeof(fragment_entry));
+	if (size < 0)
 		goto out;
 
 	*fragment_block = le64_to_cpu(fragment_entry.start_block);
diff --git a/kernel/fs/squashfs/id.c b/kernel/fs/squashfs/id.c
index 6ab0db1..f9510cd 100644
--- a/kernel/fs/squashfs/id.c
+++ b/kernel/fs/squashfs/id.c
@@ -48,10 +48,12 @@ int squashfs_get_id(struct super_block *s, unsigned int index, unsigned int *id)
 	int offset = SQUASHFS_ID_BLOCK_OFFSET(index);
 	long long start_block = le64_to_cpu(msblk->id_table[block]);
 	__le32 disk_id;
+	int err;
 
-	if (!squashfs_read_metadata(s, &disk_id, &start_block, &offset,
-				 			sizeof(disk_id)))
-		return -EIO;
+	err = squashfs_read_metadata(s, &disk_id, &start_block, &offset,
+				 			sizeof(disk_id));
+	if (err < 0)
+		return err;
 
 	*id = le32_to_cpu(disk_id);
 	return 0;
diff --git a/kernel/fs/squashfs/inode.c b/kernel/fs/squashfs/inode.c
index 7f2cef2..ccc09cc 100644
--- a/kernel/fs/squashfs/inode.c
+++ b/kernel/fs/squashfs/inode.c
@@ -120,7 +120,8 @@ int squashfs_read_inode(struct inode *i, long long inode)
 	/*
 	 * Read inode base common to all inode types.
 	 */
-	if (!squashfs_read_metadata(s, inodeb, &block, &offset, sizeof(*inodeb)))
+	err = squashfs_read_metadata(s, inodeb, &block, &offset, sizeof(*inodeb));
+	if (err < 0)
 		goto failed_read;
 
 	err = squashfs_new_inode(s, i, inodeb);
@@ -137,7 +138,9 @@ int squashfs_read_inode(struct inode *i, long long inode)
 		long long frag_blk;
 		struct squashfs_reg_inode *inodep = &id.reg;
 
-		if (!squashfs_read_metadata(s, inodep, &block, &offset,									sizeof(*inodep)))
+		err = squashfs_read_metadata(s, inodep, &block, &offset,
+							sizeof(*inodep));
+		if (err < 0)
 			goto failed_read;
 
 		frag = le32_to_cpu(inodep->fragment);
@@ -177,8 +180,9 @@ int squashfs_read_inode(struct inode *i, long long inode)
 		long long frag_blk;
 		struct squashfs_lreg_inode *inodep = &id.lreg;
 
-		if (!squashfs_read_metadata(s, inodep, &block, &offset,
-							sizeof(*inodep)))
+		err = squashfs_read_metadata(s, inodep, &block, &offset,
+							sizeof(*inodep));
+		if (err < 0)
 			goto failed_read;
 
 		frag = le32_to_cpu(inodep->fragment);
@@ -218,8 +222,9 @@ int squashfs_read_inode(struct inode *i, long long inode)
 	case SQUASHFS_DIR_TYPE: {
 		struct squashfs_dir_inode *inodep = &id.dir;
 
-		if (!squashfs_read_metadata(s, inodep, &block, &offset,
-				sizeof(*inodep)))
+		err = squashfs_read_metadata(s, inodep, &block, &offset,
+				sizeof(*inodep));
+		if (err < 0)
 			goto failed_read;
 
 		i->i_nlink = le32_to_cpu(inodep->nlink);
@@ -241,8 +246,9 @@ int squashfs_read_inode(struct inode *i, long long inode)
 	case SQUASHFS_LDIR_TYPE: {
 		struct squashfs_ldir_inode *inodep = &id.ldir;
 
-		if (!squashfs_read_metadata(s, inodep, &block, &offset,
-				sizeof(*inodep)))
+		err = squashfs_read_metadata(s, inodep, &block, &offset,
+				sizeof(*inodep));
+		if (err < 0)
 			goto failed_read;
 
 		i->i_nlink = le32_to_cpu(inodep->nlink);
@@ -266,8 +272,9 @@ int squashfs_read_inode(struct inode *i, long long inode)
 	case SQUASHFS_SYMLINK_TYPE: {
 		struct squashfs_symlink_inode *inodep = &id.symlink;
 
-		if (!squashfs_read_metadata(s, inodep, &block, &offset,
-				sizeof(*inodep)))
+		err = squashfs_read_metadata(s, inodep, &block, &offset,
+				sizeof(*inodep));
+		if (err < 0)
 			goto failed_read;
 
 		i->i_nlink = le32_to_cpu(inodep->nlink);
@@ -288,8 +295,9 @@ int squashfs_read_inode(struct inode *i, long long inode)
 		struct squashfs_dev_inode *inodep = &id.dev;
 		unsigned int rdev;
 
-		if (!squashfs_read_metadata(s, inodep, &block, &offset,
-				sizeof(*inodep)))
+		err = squashfs_read_metadata(s, inodep, &block, &offset,
+				sizeof(*inodep));
+		if (err < 0)
 			goto failed_read;
 
 		i->i_nlink = le32_to_cpu(inodep->nlink);
@@ -306,8 +314,9 @@ int squashfs_read_inode(struct inode *i, long long inode)
 	case SQUASHFS_SOCKET_TYPE: {
 		struct squashfs_ipc_inode *inodep = &id.ipc;
 
-		if (!squashfs_read_metadata(s, inodep, &block, &offset,
-				sizeof(*inodep)))
+		err = squashfs_read_metadata(s, inodep, &block, &offset,
+				sizeof(*inodep));
+		if (err < 0)
 			goto failed_read;
 
 		i->i_nlink = le32_to_cpu(inodep->nlink);
diff --git a/kernel/fs/squashfs/namei.c b/kernel/fs/squashfs/namei.c
index 5c8dd29..880be1d 100644
--- a/kernel/fs/squashfs/namei.c
+++ b/kernel/fs/squashfs/namei.c
@@ -67,6 +67,10 @@
 /*
  * Lookup name in the directory index, returning the location of the metadata
  * block containing it, and the directory index this represents.
+ *
+ * If we get an error reading the index then return the part of the index
+ * (if any) we have managed to read - the index isn't essential, just
+ * quicker.
  */
 static int get_dir_index_using_name(struct super_block *s,
 			long long *next_block, unsigned int *next_offset,
@@ -74,7 +78,7 @@ static int get_dir_index_using_name(struct super_block *s,
 			int i_count, const char *name, int len)
 {
 	struct squashfs_sb_info *msblk = s->s_fs_info;
-	int i, size, length = 0;
+	int i, size, length = 0, err;
 	struct squashfs_dir_index *index;
 	char *str;
 
@@ -91,13 +95,18 @@ static int get_dir_index_using_name(struct super_block *s,
 	str[len] = '\0';
 
 	for (i = 0; i < i_count; i++) {
-		squashfs_read_metadata(s, index, &index_start, &index_offset,
-					sizeof(*index));
+		err = squashfs_read_metadata(s, index, &index_start,
+					&index_offset, sizeof(*index));
+		if (err < 0)
+			break;
+
 
 		size = le32_to_cpu(index->size) + 1;
 
-		squashfs_read_metadata(s, index->name, &index_start,
+		err = squashfs_read_metadata(s, index->name, &index_start,
 					&index_offset, size);
+		if (err < 0)
+			break;
 
 		index->name[size] = '\0';
 
@@ -162,8 +171,9 @@ static struct dentry *squashfs_lookup(struct inode *i, struct dentry *dentry,
 		/*
 		 * Read directory header.
 		 */
-		if (!squashfs_read_metadata(i->i_sb, &dirh, &next_block,
-				&next_offset, sizeof(dirh)))
+		err = squashfs_read_metadata(i->i_sb, &dirh, &next_block,
+				&next_offset, sizeof(dirh));
+		if (err < 0)
 			goto read_failure;
 
 		length += sizeof(dirh);
@@ -173,14 +183,16 @@ static struct dentry *squashfs_lookup(struct inode *i, struct dentry *dentry,
 			/*
 			 * Read directory entry.
 			 */
-			if (!squashfs_read_metadata(i->i_sb, dire, &next_block,
-					&next_offset, sizeof(*dire)))
+			err = squashfs_read_metadata(i->i_sb, dire, &next_block,
+					&next_offset, sizeof(*dire));
+			if (err < 0)
 				goto read_failure;
 
 			size = le16_to_cpu(dire->size) + 1;
 
-			if (!squashfs_read_metadata(i->i_sb, dire->name,
-					&next_block, &next_offset, size))
+			err = squashfs_read_metadata(i->i_sb, dire->name,
+					&next_block, &next_offset, size);
+			if (err < 0)
 				goto read_failure;
 
 			length += sizeof(*dire) + size;
diff --git a/kernel/fs/squashfs/symlink.c b/kernel/fs/squashfs/symlink.c
index 1c2a07f..0881d3a 100644
--- a/kernel/fs/squashfs/symlink.c
+++ b/kernel/fs/squashfs/symlink.c
@@ -64,7 +64,7 @@ static int squashfs_symlink_readpage(struct file *file, struct page *page)
 	 */
 	if (index) {
 		bytes = squashfs_read_metadata(s, NULL, &block, &offset, index);
-		if (bytes == 0) {
+		if (bytes < 0) {
 			ERROR("Unable to read symlink [%llx:%x]\n",
 				SQUASHFS_I(inode)->start_block,
 				SQUASHFS_I(inode)->offset);