[PATCH v2 0/2] btrfs: Fix returned errno codes

[PATCH v2 0/2] btrfs: Fix returned errno codes

[Luis de Bethencourt]

Hi,

These two patches fix instances where -1 is used to specify a buffer
allocation fail, instead of using -ENOMEM.

Patch 1/2 is already reviewed by David Sterba.

Luis de Bethencourt (2):
  btrfs: check-integrity: Fix returned errno codes
  btrfs: reada: Fix returned errno code

 fs/btrfs/check-integrity.c | 4 ++--
 fs/btrfs/reada.c           | 8 +++++---
 2 files changed, 7 insertions(+), 5 deletions(-)

-- 
2.5.1

[PATCH v2 1/2] btrfs: check-integrity: Fix returned errno codes

[Luis de Bethencourt]

check-integrity is using -1 instead of the -ENOMEM defined macro to
specify that a buffer allocation failed. Since the error number is
propagated, the caller will get a -EPERM which is the wrong error
condition.

Also, the smatch tool complains with the following warnings:
btrfsic_process_superblock() warn: returning -1 instead of -ENOMEM is sloppy
btrfsic_read_block() warn: returning -1 instead of -ENOMEM is sloppy

Signed-off-by: Luis de Bethencourt <luisbg@osg.samsung.com>
Reviewed-by: David Sterba <dsterba@suse.com>
---
 fs/btrfs/check-integrity.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/fs/btrfs/check-integrity.c b/fs/btrfs/check-integrity.c
index 541fbfa..9cacd06 100644
--- a/fs/btrfs/check-integrity.c
+++ b/fs/btrfs/check-integrity.c
@@ -667,7 +667,7 @@ static int btrfsic_process_superblock(struct btrfsic_state *state,
 	selected_super = kzalloc(sizeof(*selected_super), GFP_NOFS);
 	if (NULL == selected_super) {
 		printk(KERN_INFO "btrfsic: error, kmalloc failed!\n");
-		return -1;
+		return -ENOMEM;
 	}
 
 	list_for_each_entry(device, dev_head, dev_list) {
@@ -1660,7 +1660,7 @@ static int btrfsic_read_block(struct btrfsic_state *state,
 					  sizeof(*block_ctx->pagev)) *
 					 num_pages, GFP_NOFS);
 	if (!block_ctx->mem_to_free)
-		return -1;
+		return -ENOMEM;
 	block_ctx->datav = block_ctx->mem_to_free;
 	block_ctx->pagev = (struct page **)(block_ctx->datav + num_pages);
 	for (i = 0; i < num_pages; i++) {
-- 
2.5.1

[PATCH v2 2/2] btrfs: reada: Fix returned errno code

[Luis de Bethencourt]

reada is using -1 instead of the -ENOMEM defined macro to specify that
a buffer allocation failed. Since the error number is propagated, the
caller will get a -EPERM which is the wrong error condition.

Also, updating the caller to return the exact value from
reada_add_block.

Smatch tool warning:
reada_add_block() warn: returning -1 instead of -ENOMEM is sloppy

Signed-off-by: Luis de Bethencourt <luisbg@osg.samsung.com>
---
 fs/btrfs/reada.c | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/fs/btrfs/reada.c b/fs/btrfs/reada.c
index 4645cd1..619f929 100644
--- a/fs/btrfs/reada.c
+++ b/fs/btrfs/reada.c
@@ -569,7 +569,7 @@ static int reada_add_block(struct reada_control *rc, u64 logical,
 	rec = kzalloc(sizeof(*rec), GFP_NOFS);
 	if (!rec) {
 		reada_extent_put(root->fs_info, re);
-		return -1;
+		return -ENOMEM;
 	}
 
 	rec->rc = rc;
@@ -918,6 +918,7 @@ struct reada_control *btrfs_reada_add(struct btrfs_root *root,
 	u64 start;
 	u64 generation;
 	int level;
+	int ret;
 	struct extent_buffer *node;
 	static struct btrfs_key max_key = {
 		.objectid = (u64)-1,
@@ -943,9 +944,10 @@ struct reada_control *btrfs_reada_add(struct btrfs_root *root,
 	generation = btrfs_header_generation(node);
 	free_extent_buffer(node);
 
-	if (reada_add_block(rc, start, &max_key, level, generation)) {
+	ret = reada_add_block(rc, start, &max_key, level, generation);
+	if (ret) {
 		kfree(rc);
-		return ERR_PTR(-ENOMEM);
+		return ERR_PTR(ret);
 	}
 
 	reada_start_machine(root->fs_info);
-- 
2.5.1

Re: [PATCH v2 2/2] btrfs: reada: Fix returned errno code

[David Sterba]

On Thu, Sep 24, 2015 at 08:13:33PM +0100, Luis de Bethencourt wrote:
> reada is using -1 instead of the -ENOMEM defined macro to specify that
> a buffer allocation failed. Since the error number is propagated, the
> caller will get a -EPERM which is the wrong error condition.
> 
> Also, updating the caller to return the exact value from
> reada_add_block.
> 
> Smatch tool warning:
> reada_add_block() warn: returning -1 instead of -ENOMEM is sloppy
> 
> Signed-off-by: Luis de Bethencourt <luisbg@osg.samsung.com>

Reviewed-by: David Sterba <dsterba@suse.com>