xfs: kill XBF_DONTBLOCK

Just about all callers of xfs_buf_read() and xfs_buf_get() use XBF_DONTBLOCK.
This is used to make memory allocation use GFP_NOFS rather than GFP_KERNEL to
avoid recursion through memory reclaim back into the filesystem.

All the blocking get calls in growfs occur inside a transaction, even though
they are no part of the transaction, so all allocation will be GFP_NOFS due to
the task flag PF_TRANS being set. The blocking read calls occur during log
recovery, so they will probably be unaffected by converting to GFP_NOFS
allocations.

Hence make XBF_DONTBLOCK behaviour always occur for buffers and kill the flag.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Mark Tinguely <tinguely@sgi.com>
Signed-off-by: Ben Myers <bpm@sgi.com>

1 files changed, 2 insertions, 2 deletions

diff --git a/fs/xfs/xfs_vnodeops.c b/fs/xfs/xfs_vnodeops.c
index 8f99c7781f39..6c187450f1c8 100644
--- a/fs/xfs/xfs_vnodeops.c
+++ b/fs/xfs/xfs_vnodeops.c
@@ -82,7 +82,7 @@ xfs_readlink_bmap(
                 byte_cnt = XFS_FSB_TO_B(mp, mval[n].br_blockcount);
 
                 bp = xfs_buf_read(mp->m_ddev_targp, d, BTOBB(byte_cnt),
-                                  XBF_MAPPED | XBF_DONT_BLOCK);
+                                  XBF_MAPPED);
                 if (!bp)
                         return XFS_ERROR(ENOMEM);
                 error = bp->b_error;
@@ -1966,7 +1966,7 @@ xfs_zero_remaining_bytes(
 
         bp = xfs_buf_get_uncached(XFS_IS_REALTIME_INODE(ip) ?
                                         mp->m_rtdev_targp : mp->m_ddev_targp,
-                                BTOBB(mp->m_sb.sb_blocksize), XBF_DONT_BLOCK);
+                                  BTOBB(mp->m_sb.sb_blocksize), 0);
         if (!bp)
                 return XFS_ERROR(ENOMEM);