[PATCH 2/2] Ext3: add necessary check in case IO error happens

[PATCH 2/2] Ext3: add necessary check in case IO error happens

[shilong wang]

From: Wang Shilong <wangsl-fnst@cn.fujitsu.com>

As we know IO ERROR may happen when the function 'sb_getblk' is
called. Add necessary check for it.

The patch also fix a coding style problem.

Signed-off-by: Wang Shilong <wangsl-fnst@cn.fujitsu.com>
---
 fs/ext3/inode.c |    6 +++++-
 1 files changed, 5 insertions(+), 1 deletions(-)

diff --git a/fs/ext3/inode.c b/fs/ext3/inode.c
index ff574b4..59b6178 100644
--- a/fs/ext3/inode.c
+++ b/fs/ext3/inode.c
@@ -676,6 +676,10 @@ static int ext3_alloc_branch(handle_t *handle,
struct inode *inode,
 		 * parent to disk.
 		 */
 		bh = sb_getblk(inode->i_sb, new_blocks[n-1]);
+		if (!bh) {
+			err = -EIO;
+			goto failed;
+		}
 		branch[n].bh = bh;
 		lock_buffer(bh);
 		BUFFER_TRACE(bh, "call get_create_access");
@@ -717,7 +721,7 @@ failed:
 		BUFFER_TRACE(branch[i].bh, "call journal_forget");
 		ext3_journal_forget(handle, branch[i].bh);
 	}
-	for (i = 0; i <indirect_blks; i++)
+	for (i = 0; i < indirect_blks; i++)
 		ext3_free_blocks(handle, inode, new_blocks[i], 1);

 	ext3_free_blocks(handle, inode, new_blocks[i], num);
-- 
1.7.7.6

Re: [PATCH 2/2] Ext3: add necessary check in case IO error happens

[Jan Kara]

On Fri 11-01-13 03:58:28, shilong wang wrote:
> From: Wang Shilong <wangsl-fnst@cn.fujitsu.com>
> 
> As we know IO ERROR may happen when the function 'sb_getblk' is
> called. Add necessary check for it.
> 
> The patch also fix a coding style problem.
  Thanks for the patch. I think returning ENOMEM instead of EIO would be
better. Otherwise the patch looks OK.

								Honza
> 
> Signed-off-by: Wang Shilong <wangsl-fnst@cn.fujitsu.com>
> ---
>  fs/ext3/inode.c |    6 +++++-
>  1 files changed, 5 insertions(+), 1 deletions(-)
> 
> diff --git a/fs/ext3/inode.c b/fs/ext3/inode.c
> index ff574b4..59b6178 100644
> --- a/fs/ext3/inode.c
> +++ b/fs/ext3/inode.c
> @@ -676,6 +676,10 @@ static int ext3_alloc_branch(handle_t *handle,
> struct inode *inode,
>  		 * parent to disk.
>  		 */
>  		bh = sb_getblk(inode->i_sb, new_blocks[n-1]);
> +		if (!bh) {
> +			err = -EIO;
> +			goto failed;
> +		}
>  		branch[n].bh = bh;
>  		lock_buffer(bh);
>  		BUFFER_TRACE(bh, "call get_create_access");
> @@ -717,7 +721,7 @@ failed:
>  		BUFFER_TRACE(branch[i].bh, "call journal_forget");
>  		ext3_journal_forget(handle, branch[i].bh);
>  	}
> -	for (i = 0; i <indirect_blks; i++)
> +	for (i = 0; i < indirect_blks; i++)
>  		ext3_free_blocks(handle, inode, new_blocks[i], 1);
> 
>  	ext3_free_blocks(handle, inode, new_blocks[i], num);
> -- 
> 1.7.7.6
> --
> To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html
-- 
Jan Kara <jack@suse.cz>
SUSE Labs, CR

Re: [PATCH 2/2] Ext3: add necessary check in case IO error happens

[shilong wang]

Thanks very much for your reply. I will resend the patch later,
Besides, i find there are many places where EIO is used when
'sb_getblk' fails. Shall i replace all of them with ENOMEM?
2013/1/11 Jan Kara <jack@suse.cz>:
> On Fri 11-01-13 03:58:28, shilong wang wrote:
>> From: Wang Shilong <wangsl-fnst@cn.fujitsu.com>
>>
>> As we know IO ERROR may happen when the function 'sb_getblk' is
>> called. Add necessary check for it.
>>
>> The patch also fix a coding style problem.
>   Thanks for the patch. I think returning ENOMEM instead of EIO would be
> better. Otherwise the patch looks OK.
>
>                                                                 Honza
>>
>> Signed-off-by: Wang Shilong <wangsl-fnst@cn.fujitsu.com>
>> ---
>>  fs/ext3/inode.c |    6 +++++-
>>  1 files changed, 5 insertions(+), 1 deletions(-)
>>
>> diff --git a/fs/ext3/inode.c b/fs/ext3/inode.c
>> index ff574b4..59b6178 100644
>> --- a/fs/ext3/inode.c
>> +++ b/fs/ext3/inode.c
>> @@ -676,6 +676,10 @@ static int ext3_alloc_branch(handle_t *handle,
>> struct inode *inode,
>>                * parent to disk.
>>                */
>>               bh = sb_getblk(inode->i_sb, new_blocks[n-1]);
>> +             if (!bh) {
>> +                     err = -EIO;
>> +                     goto failed;
>> +             }
>>               branch[n].bh = bh;
>>               lock_buffer(bh);
>>               BUFFER_TRACE(bh, "call get_create_access");
>> @@ -717,7 +721,7 @@ failed:
>>               BUFFER_TRACE(branch[i].bh, "call journal_forget");
>>               ext3_journal_forget(handle, branch[i].bh);
>>       }
>> -     for (i = 0; i <indirect_blks; i++)
>> +     for (i = 0; i < indirect_blks; i++)
>>               ext3_free_blocks(handle, inode, new_blocks[i], 1);
>>
>>       ext3_free_blocks(handle, inode, new_blocks[i], num);
>> --
>> 1.7.7.6
>> --
>> To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in
>> the body of a message to majordomo@vger.kernel.org
>> More majordomo info at  http://vger.kernel.org/majordomo-info.html
> --
> Jan Kara <jack@suse.cz>
> SUSE Labs, CR

Re: [PATCH 2/2] Ext3: add necessary check in case IO error happens

[Theodore Ts'o]

On Fri, Jan 11, 2013 at 05:26:33PM +0100, Jan Kara wrote:
>   Thanks for the patch. I think returning ENOMEM instead of EIO would be
> better. Otherwise the patch looks OK.

This may be because fs/ext4/inode.c was returning EIO in similar
circumstances.  I agree ENOMEM is a better error code.  I'll fix up
ext4....

						- Ted

[PATCH] ext4: return ENOMEM if sb_getblk() fails

[Theodore Ts'o]

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" <tytso@mit.edu>
Cc: stable@vger.kernel.org
---
 fs/ext4/extents.c  | 21 ++++++++++++---------
 fs/ext4/indirect.c |  9 ++++++---
 fs/ext4/inline.c   |  2 +-
 fs/ext4/inode.c    |  9 +++------
 fs/ext4/mmp.c      |  2 ++
 fs/ext4/resize.c   |  8 ++++----
 fs/ext4/xattr.c    |  3 ++-
 7 files changed, 30 insertions(+), 24 deletions(-)

diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c
index 5ae1674..6913a8d 100644
--- a/fs/ext4/extents.c
+++ b/fs/ext4/extents.c
@@ -725,6 +725,7 @@ ext4_ext_find_extent(struct inode *inode, ext4_lblk_t block,
 	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);
@@ -752,12 +753,15 @@ ext4_ext_find_extent(struct inode *inode, ext4_lblk_t block,
 		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;
 			}
@@ -768,13 +772,15 @@ ext4_ext_find_extent(struct inode *inode, ext4_lblk_t block,
 			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;
 	}
 
@@ -796,7 +802,7 @@ err:
 	ext4_ext_drop_refs(path);
 	if (alloc)
 		kfree(path);
-	return ERR_PTR(-EIO);
+	return ERR_PTR(ret);
 }
 
 /*
@@ -1136,11 +1142,8 @@ static int ext4_ext_grow_indepth(handle_t *handle, struct inode *inode,
 		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);
diff --git a/fs/ext4/indirect.c b/fs/ext4/indirect.c
index 20862f9..8d83d1e 100644
--- a/fs/ext4/indirect.c
+++ b/fs/ext4/indirect.c
@@ -146,6 +146,7 @@ static Indirect *ext4_get_branch(struct inode *inode, int depth,
 	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 */
@@ -154,8 +155,10 @@ static Indirect *ext4_get_branch(struct inode *inode, int depth,
 		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) {
@@ -177,7 +180,7 @@ static Indirect *ext4_get_branch(struct inode *inode, int depth,
 	return NULL;
 
 failure:
-	*err = -EIO;
+	*err = ret;
 no_block:
 	return p;
 }
@@ -471,7 +474,7 @@ static int ext4_alloc_branch(handle_t *handle, struct inode *inode,
 		 */
 		bh = sb_getblk(inode->i_sb, new_blocks[n-1]);
 		if (unlikely(!bh)) {
-			err = -EIO;
+			err = -ENOMEM;
 			goto failed;
 		}
 
diff --git a/fs/ext4/inline.c b/fs/ext4/inline.c
index 387c47c..93a3408 100644
--- a/fs/ext4/inline.c
+++ b/fs/ext4/inline.c
@@ -1188,7 +1188,7 @@ static int ext4_convert_inline_data_nolock(handle_t *handle,
 
 	data_bh = sb_getblk(inode->i_sb, map.m_pblk);
 	if (!data_bh) {
-		error = -EIO;
+		error = -ENOMEM;
 		goto out_restore;
 	}
 
diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index cbfe13b..9ccc140 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -714,7 +714,7 @@ struct buffer_head *ext4_getblk(handle_t *handle, struct inode *inode,
 
 	bh = sb_getblk(inode->i_sb, map.m_pblk);
 	if (!bh) {
-		*errp = -EIO;
+		*errp = -ENOMEM;
 		return NULL;
 	}
 	if (map.m_flags & EXT4_MAP_NEW) {
@@ -3660,11 +3660,8 @@ static int __ext4_get_inode_loc(struct inode *inode,
 	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);
 
diff --git a/fs/ext4/mmp.c b/fs/ext4/mmp.c
index fe7c63f..44734f1 100644
--- a/fs/ext4/mmp.c
+++ b/fs/ext4/mmp.c
@@ -80,6 +80,8 @@ static int read_mmp_block(struct super_block *sb, struct buffer_head **bh,
 	 * 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);
diff --git a/fs/ext4/resize.c b/fs/ext4/resize.c
index d99387b..02824dc 100644
--- a/fs/ext4/resize.c
+++ b/fs/ext4/resize.c
@@ -334,7 +334,7 @@ static struct buffer_head *bclean(handle_t *handle, struct super_block *sb,
 
 	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);
@@ -411,7 +411,7 @@ static int set_flexbg_block_bitmap(struct super_block *sb, handle_t *handle,
 
 		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)
@@ -501,7 +501,7 @@ static int setup_new_flex_group_blocks(struct super_block *sb,
 
 			gdb = sb_getblk(sb, block);
 			if (!gdb) {
-				err = -EIO;
+				err = -ENOMEM;
 				goto out;
 			}
 
@@ -1065,7 +1065,7 @@ static void update_backups(struct super_block *sb, int blk_off, char *data,
 
 		bh = sb_getblk(sb, backup_block);
 		if (!bh) {
-			err = -EIO;
+			err = -ENOMEM;
 			break;
 		}
 		ext4_debug("update metadata backup %llu(+%llu)\n",
diff --git a/fs/ext4/xattr.c b/fs/ext4/xattr.c
index 3a91ebc..07d684a 100644
--- a/fs/ext4/xattr.c
+++ b/fs/ext4/xattr.c
@@ -887,16 +887,17 @@ inserted:
 
 			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);
-- 
1.7.12.rc0.22.gcdd159b