ext4: return ENOMEM if sb_getblk() fails

The only reason for sb_getblk() failing is if it can't allocate the
buffer_head. So ENOMEM is more appropriate than EIO. In addition,
make sure that the file system is marked as being inconsistent if
sb_getblk() fails.

Signed-off-by: "Theodore Ts'o" <[e-mail]>
Cc: [e-mail]

fs/ext4/extents.c

···
 	struct ext4_extent_header *eh;
 	struct buffer_head *bh;
 	short int depth, i, ppos = 0, alloc = 0;
+	int ret;
 
 	eh = ext_inode_hdr(inode);
 	depth = ext_depth(inode);
···
 		path[ppos].p_ext = NULL;
 
 		bh = sb_getblk(inode->i_sb, path[ppos].p_block);
-		if (unlikely(!bh))
+		if (unlikely(!bh)) {
+			ret = -ENOMEM;
 			goto err;
+		}
 		if (!bh_uptodate_or_lock(bh)) {
 			trace_ext4_ext_load_extent(inode, block,
 						path[ppos].p_block);
-			if (bh_submit_read(bh) < 0) {
+			ret = bh_submit_read(bh);
+			if (ret < 0) {
 				put_bh(bh);
 				goto err;
 			}
···
 			put_bh(bh);
 			EXT4_ERROR_INODE(inode,
 					 "ppos %d > depth %d", ppos, depth);
+			ret = -EIO;
 			goto err;
 		}
 		path[ppos].p_bh = bh;
 		path[ppos].p_hdr = eh;
 		i--;
 
-		if (ext4_ext_check_block(inode, eh, i, bh))
+		ret = ext4_ext_check_block(inode, eh, i, bh);
+		if (ret < 0)
 			goto err;
 	}
 
···
 	ext4_ext_drop_refs(path);
 	if (alloc)
 		kfree(path);
-	return ERR_PTR(-EIO);
+	return ERR_PTR(ret);
 }
 
 /*
···
 	}
 	bh = sb_getblk(inode->i_sb, newblock);
 	if (!bh) {
-		err = -EIO;
+		err = -ENOMEM;
 		goto cleanup;
 	}
 	lock_buffer(bh);
···
 		newblock = ablocks[--a];
 		bh = sb_getblk(inode->i_sb, newblock);
 		if (!bh) {
-			err = -EIO;
+			err = -ENOMEM;
 			goto cleanup;
 		}
 		lock_buffer(bh);
···
 		return err;
 
 	bh = sb_getblk(inode->i_sb, newblock);
-	if (!bh) {
-		err = -EIO;
-		ext4_std_error(inode->i_sb, err);
-		return err;
-	}
+	if (!bh)
+		return -ENOMEM;
 	lock_buffer(bh);
 
 	err = ext4_journal_get_create_access(handle, bh);

fs/ext4/indirect.c

···
 	struct super_block *sb = inode->i_sb;
 	Indirect *p = chain;
 	struct buffer_head *bh;
+	int ret = -EIO;
 
 	*err = 0;
 	/* i_data is not going away, no lock needed */
···
 		goto no_block;
 	while (--depth) {
 		bh = sb_getblk(sb, le32_to_cpu(p->key));
-		if (unlikely(!bh))
+		if (unlikely(!bh)) {
+			ret = -ENOMEM;
 			goto failure;
+		}
 
 		if (!bh_uptodate_or_lock(bh)) {
 			if (bh_submit_read(bh) < 0) {
···
 	return NULL;
 
 failure:
-	*err = -EIO;
+	*err = ret;
 no_block:
 	return p;
 }
···
 		 */
 		bh = sb_getblk(inode->i_sb, new_blocks[n-1]);
 		if (unlikely(!bh)) {
-			err = -EIO;
+			err = -ENOMEM;
 			goto failed;
 		}
 

fs/ext4/inline.c

···
 
 	data_bh = sb_getblk(inode->i_sb, map.m_pblk);
 	if (!data_bh) {
-		error = -EIO;
+		error = -ENOMEM;
 		goto out_restore;
 	}
 

fs/ext4/inode.c

···
 
 	bh = sb_getblk(inode->i_sb, map.m_pblk);
 	if (!bh) {
-		*errp = -EIO;
+		*errp = -ENOMEM;
 		return NULL;
 	}
 	if (map.m_flags & EXT4_MAP_NEW) {
···
 	iloc->offset = (inode_offset % inodes_per_block) * EXT4_INODE_SIZE(sb);
 
 	bh = sb_getblk(sb, block);
-	if (!bh) {
-		EXT4_ERROR_INODE_BLOCK(inode, block,
-				       "unable to read itable block");
-		return -EIO;
-	}
+	if (!bh)
+		return -ENOMEM;
 	if (!buffer_uptodate(bh)) {
 		lock_buffer(bh);
 

fs/ext4/mmp.c

···
 	 * is not blocked in the elevator. */
 	if (!*bh)
 		*bh = sb_getblk(sb, mmp_block);
+	if (!*bh)
+		return -ENOMEM;
 	if (*bh) {
 		get_bh(*bh);
 		lock_buffer(*bh);

fs/ext4/resize.c

···
 
 	bh = sb_getblk(sb, blk);
 	if (!bh)
-		return ERR_PTR(-EIO);
+		return ERR_PTR(-ENOMEM);
 	if ((err = ext4_journal_get_write_access(handle, bh))) {
 		brelse(bh);
 		bh = ERR_PTR(err);
···
 
 		bh = sb_getblk(sb, flex_gd->groups[group].block_bitmap);
 		if (!bh)
-			return -EIO;
+			return -ENOMEM;
 
 		err = ext4_journal_get_write_access(handle, bh);
 		if (err)
···
 
 			gdb = sb_getblk(sb, block);
 			if (!gdb) {
-				err = -EIO;
+				err = -ENOMEM;
 				goto out;
 			}
 
···
 
 		bh = sb_getblk(sb, backup_block);
 		if (!bh) {
-			err = -EIO;
+			err = -ENOMEM;
 			break;
 		}
 		ext4_debug("update metadata backup %llu(+%llu)\n",

fs/ext4/xattr.c

···
 
 			new_bh = sb_getblk(sb, block);
 			if (!new_bh) {
+				error = -ENOMEM;
 getblk_failed:
 				ext4_free_blocks(handle, inode, NULL, block, 1,
 						 EXT4_FREE_BLOCKS_METADATA);
-				error = -EIO;
 				goto cleanup;
 			}
 			lock_buffer(new_bh);
 			error = ext4_journal_get_create_access(handle, new_bh);
 			if (error) {
 				unlock_buffer(new_bh);
+				error = -EIO;
 				goto getblk_failed;
 			}
 			memcpy(new_bh->b_data, s->base, new_bh->b_size);