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[8/9] Revert "ext4: avoid deadlocks in the writeback path by using sb_getblk_gfp"

Message ID 20161215140715.12732-9-mhocko@kernel.org (mailing list archive)
State Not Applicable
Headers show

Commit Message

Michal Hocko Dec. 15, 2016, 2:07 p.m. UTC
From: Michal Hocko <mhocko@suse.com>

This reverts commit c45653c341f5c8a0ce19c8f0ad4678640849cb86 because
sb_getblk_gfp is not really needed as
sb_getblk
  __getblk_gfp
    __getblk_slow
      grow_buffers
        grow_dev_page
	  gfp_mask = mapping_gfp_constraint(inode->i_mapping, ~__GFP_FS) | gfp

so __GFP_FS is cleared unconditionally and therefore the above commit
didn't have any real effect in fact.

This patch should not introduce any functional change. The main point
of this change is to reduce explicit GFP_NOFS usage inside ext4 code to
make the review of the remaining usage easier.

Signed-off-by: Michal Hocko <mhocko@suse.com>
---
 fs/ext4/extents.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

Comments

Jan Kara Dec. 16, 2016, 8:41 a.m. UTC | #1
On Thu 15-12-16 15:07:14, Michal Hocko wrote:
> From: Michal Hocko <mhocko@suse.com>
> 
> This reverts commit c45653c341f5c8a0ce19c8f0ad4678640849cb86 because
> sb_getblk_gfp is not really needed as
> sb_getblk
>   __getblk_gfp
>     __getblk_slow
>       grow_buffers
>         grow_dev_page
> 	  gfp_mask = mapping_gfp_constraint(inode->i_mapping, ~__GFP_FS) | gfp
> 
> so __GFP_FS is cleared unconditionally and therefore the above commit
> didn't have any real effect in fact.
> 
> This patch should not introduce any functional change. The main point
> of this change is to reduce explicit GFP_NOFS usage inside ext4 code to
> make the review of the remaining usage easier.
> 
> Signed-off-by: Michal Hocko <mhocko@suse.com>

Looks good to me. You can add:

Reviewed-by: Jan Kara <jack@suse.cz>

								Honza

> ---
>  fs/ext4/extents.c | 6 +++---
>  1 file changed, 3 insertions(+), 3 deletions(-)
> 
> diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c
> index b1f8416923ab..ef815eb72389 100644
> --- a/fs/ext4/extents.c
> +++ b/fs/ext4/extents.c
> @@ -518,7 +518,7 @@ __read_extent_tree_block(const char *function, unsigned int line,
>  	struct buffer_head		*bh;
>  	int				err;
>  
> -	bh = sb_getblk_gfp(inode->i_sb, pblk, __GFP_MOVABLE | GFP_NOFS);
> +	bh = sb_getblk(inode->i_sb, pblk);
>  	if (unlikely(!bh))
>  		return ERR_PTR(-ENOMEM);
>  
> @@ -1096,7 +1096,7 @@ static int ext4_ext_split(handle_t *handle, struct inode *inode,
>  		err = -EFSCORRUPTED;
>  		goto cleanup;
>  	}
> -	bh = sb_getblk_gfp(inode->i_sb, newblock, __GFP_MOVABLE | GFP_NOFS);
> +	bh = sb_getblk(inode->i_sb, newblock);
>  	if (unlikely(!bh)) {
>  		err = -ENOMEM;
>  		goto cleanup;
> @@ -1290,7 +1290,7 @@ static int ext4_ext_grow_indepth(handle_t *handle, struct inode *inode,
>  	if (newblock == 0)
>  		return err;
>  
> -	bh = sb_getblk_gfp(inode->i_sb, newblock, __GFP_MOVABLE | GFP_NOFS);
> +	bh = sb_getblk(inode->i_sb, newblock);
>  	if (unlikely(!bh))
>  		return -ENOMEM;
>  	lock_buffer(bh);
> -- 
> 2.10.2
>
diff mbox

Patch

diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c
index b1f8416923ab..ef815eb72389 100644
--- a/fs/ext4/extents.c
+++ b/fs/ext4/extents.c
@@ -518,7 +518,7 @@  __read_extent_tree_block(const char *function, unsigned int line,
 	struct buffer_head		*bh;
 	int				err;
 
-	bh = sb_getblk_gfp(inode->i_sb, pblk, __GFP_MOVABLE | GFP_NOFS);
+	bh = sb_getblk(inode->i_sb, pblk);
 	if (unlikely(!bh))
 		return ERR_PTR(-ENOMEM);
 
@@ -1096,7 +1096,7 @@  static int ext4_ext_split(handle_t *handle, struct inode *inode,
 		err = -EFSCORRUPTED;
 		goto cleanup;
 	}
-	bh = sb_getblk_gfp(inode->i_sb, newblock, __GFP_MOVABLE | GFP_NOFS);
+	bh = sb_getblk(inode->i_sb, newblock);
 	if (unlikely(!bh)) {
 		err = -ENOMEM;
 		goto cleanup;
@@ -1290,7 +1290,7 @@  static int ext4_ext_grow_indepth(handle_t *handle, struct inode *inode,
 	if (newblock == 0)
 		return err;
 
-	bh = sb_getblk_gfp(inode->i_sb, newblock, __GFP_MOVABLE | GFP_NOFS);
+	bh = sb_getblk(inode->i_sb, newblock);
 	if (unlikely(!bh))
 		return -ENOMEM;
 	lock_buffer(bh);