diff mbox

btrfs: silence compiler warning when fs_info is not used

Message ID 1474472599-11278-1-git-send-email-dsterba@suse.com (mailing list archive)
State Superseded
Headers show

Commit Message

David Sterba Sept. 21, 2016, 3:43 p.m. UTC 
Some functions introduced a local fs_info pointer for the message
helpers. If btrfs_debug results to an empty macro, the fs_info pointer
is reported to be unused. Splitting the variable declaration and setting
will silence the warning, without any functional change.

Signed-off-by: David Sterba <dsterba@suse.com>
---
 fs/btrfs/extent_io.c |  4 +++-
 fs/btrfs/send.c      | 33 ++++++++++++++++++++++-----------
 2 files changed, 25 insertions(+), 12 deletions(-)

Comments

Jeff Mahoney Sept. 21, 2016, 3:47 p.m. UTC | #1 
On 9/21/16 11:43 AM, David Sterba wrote:
> Some functions introduced a local fs_info pointer for the message
> helpers. If btrfs_debug results to an empty macro, the fs_info pointer
> is reported to be unused. Splitting the variable declaration and setting
> will silence the warning, without any functional change.

I'm investigating fixing this differently.  I'd like the no-call version
to silence the warning and let gcc optimize it out behind the seems if
possible.

-Jeff

> Signed-off-by: David Sterba <dsterba@suse.com>
> ---
>  fs/btrfs/extent_io.c |  4 +++-
>  fs/btrfs/send.c      | 33 ++++++++++++++++++++++-----------
>  2 files changed, 25 insertions(+), 12 deletions(-)
> 
> diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
> index dac448f056ae..e9364f2cff11 100644
> --- a/fs/btrfs/extent_io.c
> +++ b/fs/btrfs/extent_io.c
> @@ -2188,7 +2188,7 @@ void btrfs_free_io_failure_record(struct inode *inode, u64 start, u64 end)
>  int btrfs_get_io_failure_record(struct inode *inode, u64 start, u64 end,
>  		struct io_failure_record **failrec_ret)
>  {
> -	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
> +	struct btrfs_fs_info *fs_info;
>  	struct io_failure_record *failrec;
>  	struct extent_map *em;
>  	struct extent_io_tree *failure_tree = &BTRFS_I(inode)->io_failure_tree;
> @@ -2197,6 +2197,8 @@ int btrfs_get_io_failure_record(struct inode *inode, u64 start, u64 end,
>  	int ret;
>  	u64 logical;
>  
> +	fs_info = btrfs_sb(inode->i_sb);
> +
>  	ret = get_state_failrec(failure_tree, start, &failrec);
>  	if (ret) {
>  		failrec = kzalloc(sizeof(*failrec), GFP_NOFS);
> diff --git a/fs/btrfs/send.c b/fs/btrfs/send.c
> index 978796865bfc..596dbab0618d 100644
> --- a/fs/btrfs/send.c
> +++ b/fs/btrfs/send.c
> @@ -723,9 +723,10 @@ static int send_cmd(struct send_ctx *sctx)
>  static int send_rename(struct send_ctx *sctx,
>  		     struct fs_path *from, struct fs_path *to)
>  {
> -	struct btrfs_fs_info *fs_info = sctx->send_root->fs_info;
> +	struct btrfs_fs_info *fs_info;
>  	int ret;
>  
> +	fs_info = sctx->send_root->fs_info;
>  	btrfs_debug(fs_info, "send_rename %s -> %s", from->start, to->start);
>  
>  	ret = begin_cmd(sctx, BTRFS_SEND_C_RENAME);
> @@ -748,9 +749,10 @@ static int send_rename(struct send_ctx *sctx,
>  static int send_link(struct send_ctx *sctx,
>  		     struct fs_path *path, struct fs_path *lnk)
>  {
> -	struct btrfs_fs_info *fs_info = sctx->send_root->fs_info;
> +	struct btrfs_fs_info *fs_info;
>  	int ret;
>  
> +	fs_info = sctx->send_root->fs_info;
>  	btrfs_debug(fs_info, "send_link %s -> %s", path->start, lnk->start);
>  
>  	ret = begin_cmd(sctx, BTRFS_SEND_C_LINK);
> @@ -772,9 +774,10 @@ static int send_link(struct send_ctx *sctx,
>   */
>  static int send_unlink(struct send_ctx *sctx, struct fs_path *path)
>  {
> -	struct btrfs_fs_info *fs_info = sctx->send_root->fs_info;
> +	struct btrfs_fs_info *fs_info;
>  	int ret;
>  
> +	fs_info = sctx->send_root->fs_info;
>  	btrfs_debug(fs_info, "send_unlink %s", path->start);
>  
>  	ret = begin_cmd(sctx, BTRFS_SEND_C_UNLINK);
> @@ -795,9 +798,10 @@ static int send_unlink(struct send_ctx *sctx, struct fs_path *path)
>   */
>  static int send_rmdir(struct send_ctx *sctx, struct fs_path *path)
>  {
> -	struct btrfs_fs_info *fs_info = sctx->send_root->fs_info;
> +	struct btrfs_fs_info *fs_info;
>  	int ret;
>  
> +	fs_info = sctx->send_root->fs_info;
>  	btrfs_debug(fs_info, "send_rmdir %s", path->start);
>  
>  	ret = begin_cmd(sctx, BTRFS_SEND_C_RMDIR);
> @@ -2422,10 +2426,11 @@ static int send_subvol_begin(struct send_ctx *sctx)
>  
>  static int send_truncate(struct send_ctx *sctx, u64 ino, u64 gen, u64 size)
>  {
> -	struct btrfs_fs_info *fs_info = sctx->send_root->fs_info;
> +	struct btrfs_fs_info *fs_info;
>  	int ret = 0;
>  	struct fs_path *p;
>  
> +	fs_info = sctx->send_root->fs_info;
>  	btrfs_debug(fs_info, "send_truncate %llu size=%llu", ino, size);
>  
>  	p = fs_path_alloc();
> @@ -2452,10 +2457,11 @@ static int send_truncate(struct send_ctx *sctx, u64 ino, u64 gen, u64 size)
>  
>  static int send_chmod(struct send_ctx *sctx, u64 ino, u64 gen, u64 mode)
>  {
> -	struct btrfs_fs_info *fs_info = sctx->send_root->fs_info;
> +	struct btrfs_fs_info *fs_info;
>  	int ret = 0;
>  	struct fs_path *p;
>  
> +	fs_info = sctx->send_root->fs_info;
>  	btrfs_debug(fs_info, "send_chmod %llu mode=%llu", ino, mode);
>  
>  	p = fs_path_alloc();
> @@ -2482,10 +2488,11 @@ static int send_chmod(struct send_ctx *sctx, u64 ino, u64 gen, u64 mode)
>  
>  static int send_chown(struct send_ctx *sctx, u64 ino, u64 gen, u64 uid, u64 gid)
>  {
> -	struct btrfs_fs_info *fs_info = sctx->send_root->fs_info;
> +	struct btrfs_fs_info *fs_info;
>  	int ret = 0;
>  	struct fs_path *p;
>  
> +	fs_info = sctx->send_root->fs_info;
>  	btrfs_debug(fs_info, "send_chown %llu uid=%llu, gid=%llu",
>  		    ino, uid, gid);
>  
> @@ -2514,7 +2521,7 @@ static int send_chown(struct send_ctx *sctx, u64 ino, u64 gen, u64 uid, u64 gid)
>  
>  static int send_utimes(struct send_ctx *sctx, u64 ino, u64 gen)
>  {
> -	struct btrfs_fs_info *fs_info = sctx->send_root->fs_info;
> +	struct btrfs_fs_info *fs_info;
>  	int ret = 0;
>  	struct fs_path *p = NULL;
>  	struct btrfs_inode_item *ii;
> @@ -2523,6 +2530,7 @@ static int send_utimes(struct send_ctx *sctx, u64 ino, u64 gen)
>  	struct btrfs_key key;
>  	int slot;
>  
> +	fs_info = sctx->send_root->fs_info;
>  	btrfs_debug(fs_info, "send_utimes %llu", ino);
>  
>  	p = fs_path_alloc();
> @@ -2577,7 +2585,7 @@ static int send_utimes(struct send_ctx *sctx, u64 ino, u64 gen)
>   */
>  static int send_create_inode(struct send_ctx *sctx, u64 ino)
>  {
> -	struct btrfs_fs_info *fs_info = sctx->send_root->fs_info;
> +	struct btrfs_fs_info *fs_info;
>  	int ret = 0;
>  	struct fs_path *p;
>  	int cmd;
> @@ -2585,6 +2593,7 @@ static int send_create_inode(struct send_ctx *sctx, u64 ino)
>  	u64 mode;
>  	u64 rdev;
>  
> +	fs_info = sctx->send_root->fs_info;
>  	btrfs_debug(fs_info, "send_create_inode %llu", ino);
>  
>  	p = fs_path_alloc();
> @@ -3643,7 +3652,7 @@ static int wait_for_parent_move(struct send_ctx *sctx,
>   */
>  static int process_recorded_refs(struct send_ctx *sctx, int *pending_move)
>  {
> -	struct btrfs_fs_info *fs_info = sctx->send_root->fs_info;
> +	struct btrfs_fs_info *fs_info;
>  	int ret = 0;
>  	struct recorded_ref *cur;
>  	struct recorded_ref *cur2;
> @@ -3656,6 +3665,7 @@ static int process_recorded_refs(struct send_ctx *sctx, int *pending_move)
>  	u64 last_dir_ino_rm = 0;
>  	bool can_rename = true;
>  
> +	fs_info = sctx->send_root->fs_info;
>  	btrfs_debug(fs_info, "process_recorded_refs %llu", sctx->cur_ino);
>  
>  	/*
> @@ -4666,7 +4676,7 @@ static ssize_t fill_read_buf(struct send_ctx *sctx, u64 offset, u32 len)
>   */
>  static int send_write(struct send_ctx *sctx, u64 offset, u32 len)
>  {
> -	struct btrfs_fs_info *fs_info = sctx->send_root->fs_info;
> +	struct btrfs_fs_info *fs_info;
>  	int ret = 0;
>  	struct fs_path *p;
>  	ssize_t num_read = 0;
> @@ -4675,6 +4685,7 @@ static int send_write(struct send_ctx *sctx, u64 offset, u32 len)
>  	if (!p)
>  		return -ENOMEM;
>  
> +	fs_info = sctx->send_root->fs_info;
>  	btrfs_debug(fs_info, "send_write offset=%llu, len=%d", offset, len);
>  
>  	num_read = fill_read_buf(sctx, offset, len);
>
diff mbox

Patch

diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
index dac448f056ae..e9364f2cff11 100644
--- a/fs/btrfs/extent_io.c
+++ b/fs/btrfs/extent_io.c
@@ -2188,7 +2188,7 @@  void btrfs_free_io_failure_record(struct inode *inode, u64 start, u64 end)
 int btrfs_get_io_failure_record(struct inode *inode, u64 start, u64 end,
 		struct io_failure_record **failrec_ret)
 {
-	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
+	struct btrfs_fs_info *fs_info;
 	struct io_failure_record *failrec;
 	struct extent_map *em;
 	struct extent_io_tree *failure_tree = &BTRFS_I(inode)->io_failure_tree;
@@ -2197,6 +2197,8 @@  int btrfs_get_io_failure_record(struct inode *inode, u64 start, u64 end,
 	int ret;
 	u64 logical;
 
+	fs_info = btrfs_sb(inode->i_sb);
+
 	ret = get_state_failrec(failure_tree, start, &failrec);
 	if (ret) {
 		failrec = kzalloc(sizeof(*failrec), GFP_NOFS);
diff --git a/fs/btrfs/send.c b/fs/btrfs/send.c
index 978796865bfc..596dbab0618d 100644
--- a/fs/btrfs/send.c
+++ b/fs/btrfs/send.c
@@ -723,9 +723,10 @@  static int send_cmd(struct send_ctx *sctx)
 static int send_rename(struct send_ctx *sctx,
 		     struct fs_path *from, struct fs_path *to)
 {
-	struct btrfs_fs_info *fs_info = sctx->send_root->fs_info;
+	struct btrfs_fs_info *fs_info;
 	int ret;
 
+	fs_info = sctx->send_root->fs_info;
 	btrfs_debug(fs_info, "send_rename %s -> %s", from->start, to->start);
 
 	ret = begin_cmd(sctx, BTRFS_SEND_C_RENAME);
@@ -748,9 +749,10 @@  static int send_rename(struct send_ctx *sctx,
 static int send_link(struct send_ctx *sctx,
 		     struct fs_path *path, struct fs_path *lnk)
 {
-	struct btrfs_fs_info *fs_info = sctx->send_root->fs_info;
+	struct btrfs_fs_info *fs_info;
 	int ret;
 
+	fs_info = sctx->send_root->fs_info;
 	btrfs_debug(fs_info, "send_link %s -> %s", path->start, lnk->start);
 
 	ret = begin_cmd(sctx, BTRFS_SEND_C_LINK);
@@ -772,9 +774,10 @@  static int send_link(struct send_ctx *sctx,
  */
 static int send_unlink(struct send_ctx *sctx, struct fs_path *path)
 {
-	struct btrfs_fs_info *fs_info = sctx->send_root->fs_info;
+	struct btrfs_fs_info *fs_info;
 	int ret;
 
+	fs_info = sctx->send_root->fs_info;
 	btrfs_debug(fs_info, "send_unlink %s", path->start);
 
 	ret = begin_cmd(sctx, BTRFS_SEND_C_UNLINK);
@@ -795,9 +798,10 @@  static int send_unlink(struct send_ctx *sctx, struct fs_path *path)
  */
 static int send_rmdir(struct send_ctx *sctx, struct fs_path *path)
 {
-	struct btrfs_fs_info *fs_info = sctx->send_root->fs_info;
+	struct btrfs_fs_info *fs_info;
 	int ret;
 
+	fs_info = sctx->send_root->fs_info;
 	btrfs_debug(fs_info, "send_rmdir %s", path->start);
 
 	ret = begin_cmd(sctx, BTRFS_SEND_C_RMDIR);
@@ -2422,10 +2426,11 @@  static int send_subvol_begin(struct send_ctx *sctx)
 
 static int send_truncate(struct send_ctx *sctx, u64 ino, u64 gen, u64 size)
 {
-	struct btrfs_fs_info *fs_info = sctx->send_root->fs_info;
+	struct btrfs_fs_info *fs_info;
 	int ret = 0;
 	struct fs_path *p;
 
+	fs_info = sctx->send_root->fs_info;
 	btrfs_debug(fs_info, "send_truncate %llu size=%llu", ino, size);
 
 	p = fs_path_alloc();
@@ -2452,10 +2457,11 @@  static int send_truncate(struct send_ctx *sctx, u64 ino, u64 gen, u64 size)
 
 static int send_chmod(struct send_ctx *sctx, u64 ino, u64 gen, u64 mode)
 {
-	struct btrfs_fs_info *fs_info = sctx->send_root->fs_info;
+	struct btrfs_fs_info *fs_info;
 	int ret = 0;
 	struct fs_path *p;
 
+	fs_info = sctx->send_root->fs_info;
 	btrfs_debug(fs_info, "send_chmod %llu mode=%llu", ino, mode);
 
 	p = fs_path_alloc();
@@ -2482,10 +2488,11 @@  static int send_chmod(struct send_ctx *sctx, u64 ino, u64 gen, u64 mode)
 
 static int send_chown(struct send_ctx *sctx, u64 ino, u64 gen, u64 uid, u64 gid)
 {
-	struct btrfs_fs_info *fs_info = sctx->send_root->fs_info;
+	struct btrfs_fs_info *fs_info;
 	int ret = 0;
 	struct fs_path *p;
 
+	fs_info = sctx->send_root->fs_info;
 	btrfs_debug(fs_info, "send_chown %llu uid=%llu, gid=%llu",
 		    ino, uid, gid);
 
@@ -2514,7 +2521,7 @@  static int send_chown(struct send_ctx *sctx, u64 ino, u64 gen, u64 uid, u64 gid)
 
 static int send_utimes(struct send_ctx *sctx, u64 ino, u64 gen)
 {
-	struct btrfs_fs_info *fs_info = sctx->send_root->fs_info;
+	struct btrfs_fs_info *fs_info;
 	int ret = 0;
 	struct fs_path *p = NULL;
 	struct btrfs_inode_item *ii;
@@ -2523,6 +2530,7 @@  static int send_utimes(struct send_ctx *sctx, u64 ino, u64 gen)
 	struct btrfs_key key;
 	int slot;
 
+	fs_info = sctx->send_root->fs_info;
 	btrfs_debug(fs_info, "send_utimes %llu", ino);
 
 	p = fs_path_alloc();
@@ -2577,7 +2585,7 @@  static int send_utimes(struct send_ctx *sctx, u64 ino, u64 gen)
  */
 static int send_create_inode(struct send_ctx *sctx, u64 ino)
 {
-	struct btrfs_fs_info *fs_info = sctx->send_root->fs_info;
+	struct btrfs_fs_info *fs_info;
 	int ret = 0;
 	struct fs_path *p;
 	int cmd;
@@ -2585,6 +2593,7 @@  static int send_create_inode(struct send_ctx *sctx, u64 ino)
 	u64 mode;
 	u64 rdev;
 
+	fs_info = sctx->send_root->fs_info;
 	btrfs_debug(fs_info, "send_create_inode %llu", ino);
 
 	p = fs_path_alloc();
@@ -3643,7 +3652,7 @@  static int wait_for_parent_move(struct send_ctx *sctx,
  */
 static int process_recorded_refs(struct send_ctx *sctx, int *pending_move)
 {
-	struct btrfs_fs_info *fs_info = sctx->send_root->fs_info;
+	struct btrfs_fs_info *fs_info;
 	int ret = 0;
 	struct recorded_ref *cur;
 	struct recorded_ref *cur2;
@@ -3656,6 +3665,7 @@  static int process_recorded_refs(struct send_ctx *sctx, int *pending_move)
 	u64 last_dir_ino_rm = 0;
 	bool can_rename = true;
 
+	fs_info = sctx->send_root->fs_info;
 	btrfs_debug(fs_info, "process_recorded_refs %llu", sctx->cur_ino);
 
 	/*
@@ -4666,7 +4676,7 @@  static ssize_t fill_read_buf(struct send_ctx *sctx, u64 offset, u32 len)
  */
 static int send_write(struct send_ctx *sctx, u64 offset, u32 len)
 {
-	struct btrfs_fs_info *fs_info = sctx->send_root->fs_info;
+	struct btrfs_fs_info *fs_info;
 	int ret = 0;
 	struct fs_path *p;
 	ssize_t num_read = 0;
@@ -4675,6 +4685,7 @@  static int send_write(struct send_ctx *sctx, u64 offset, u32 len)
 	if (!p)
 		return -ENOMEM;
 
+	fs_info = sctx->send_root->fs_info;
 	btrfs_debug(fs_info, "send_write offset=%llu, len=%d", offset, len);
 
 	num_read = fill_read_buf(sctx, offset, len);