ext4: avoid deadlocks in the writeback path by using sb_getblk_gfp

Switch ext4 to using sb_getblk_gfp with GFP_NOFS added to fix possible
deadlocks in the page writeback path.

Signed-off-by: Nikolay Borisov <kernel@kyup.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@vger.kernel.org

1 files changed, 3 insertions, 3 deletions

diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c
index d86d2622f826..69af30e0d75d 100644
--- a/fs/ext4/extents.c
+++ b/fs/ext4/extents.c
@@ -503,7 +503,7 @@ __read_extent_tree_block(const char *function, unsigned int line,
         struct buffer_head              *bh;
         int                             err;
 
-        bh = sb_getblk(inode->i_sb, pblk);
+        bh = sb_getblk_gfp(inode->i_sb, pblk, __GFP_MOVABLE | GFP_NOFS);
         if (unlikely(!bh))
                 return ERR_PTR(-ENOMEM);
 
@@ -1088,7 +1088,7 @@ static int ext4_ext_split(handle_t *handle, struct inode *inode,
                 err = -EIO;
                 goto cleanup;
         }
-        bh = sb_getblk(inode->i_sb, newblock);
+        bh = sb_getblk_gfp(inode->i_sb, newblock, __GFP_MOVABLE | GFP_NOFS);
         if (unlikely(!bh)) {
                 err = -ENOMEM;
                 goto cleanup;
@@ -1282,7 +1282,7 @@ static int ext4_ext_grow_indepth(handle_t *handle, struct inode *inode,
         if (newblock == 0)
                 return err;
 
-        bh = sb_getblk(inode->i_sb, newblock);
+        bh = sb_getblk_gfp(inode->i_sb, newblock, __GFP_MOVABLE | GFP_NOFS);
         if (unlikely(!bh))
                 return -ENOMEM;
         lock_buffer(bh);