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>
diff --git a/fs/xfs/xfs_trans_buf.c b/fs/xfs/xfs_trans_buf.c
index 5e4cf61..ccc6da1 100644
--- a/fs/xfs/xfs_trans_buf.c
+++ b/fs/xfs/xfs_trans_buf.c
@@ -148,8 +148,7 @@
* Default to a normal get_buf() call if the tp is NULL.
*/
if (tp == NULL)
- return xfs_buf_get(target_dev, blkno, len,
- flags | XBF_DONT_BLOCK);
+ return xfs_buf_get(target_dev, blkno, len, flags);
/*
* If we find the buffer in the cache with this transaction
@@ -174,15 +173,7 @@
return (bp);
}
- /*
- * We always specify the XBF_DONT_BLOCK flag within a transaction
- * so that get_buf does not try to push out a delayed write buffer
- * which might cause another transaction to take place (if the
- * buffer was delayed alloc). Such recursive transactions can
- * easily deadlock with our current transaction as well as cause
- * us to run out of stack space.
- */
- bp = xfs_buf_get(target_dev, blkno, len, flags | XBF_DONT_BLOCK);
+ bp = xfs_buf_get(target_dev, blkno, len, flags);
if (bp == NULL) {
return NULL;
}
@@ -283,7 +274,7 @@
* Default to a normal get_buf() call if the tp is NULL.
*/
if (tp == NULL) {
- bp = xfs_buf_read(target, blkno, len, flags | XBF_DONT_BLOCK);
+ bp = xfs_buf_read(target, blkno, len, flags);
if (!bp)
return (flags & XBF_TRYLOCK) ?
EAGAIN : XFS_ERROR(ENOMEM);
@@ -367,15 +358,7 @@
return 0;
}
- /*
- * We always specify the XBF_DONT_BLOCK flag within a transaction
- * so that get_buf does not try to push out a delayed write buffer
- * which might cause another transaction to take place (if the
- * buffer was delayed alloc). Such recursive transactions can
- * easily deadlock with our current transaction as well as cause
- * us to run out of stack space.
- */
- bp = xfs_buf_read(target, blkno, len, flags | XBF_DONT_BLOCK);
+ bp = xfs_buf_read(target, blkno, len, flags);
if (bp == NULL) {
*bpp = NULL;
return (flags & XBF_TRYLOCK) ?