GFS2: rewrite fallocate code to write blocks directly
GFS2's fallocate code currently goes through the page cache. Since it's only
writing to the end of the file or to holes in it, it doesn't need to, and it
was causing issues on low memory environments. This patch pulls in some of
Steve's block allocation work, and uses it to simply allocate the blocks for
the file, and zero them out at allocation time. It provides a slight
performance increase, and it dramatically simplifies the code.
Signed-off-by: Benjamin Marzinski <bmarzins@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
diff --git a/fs/gfs2/bmap.c b/fs/gfs2/bmap.c
index 834cd94..97b6195 100644
--- a/fs/gfs2/bmap.c
+++ b/fs/gfs2/bmap.c
@@ -10,6 +10,7 @@
#include <linux/spinlock.h>
#include <linux/completion.h>
#include <linux/buffer_head.h>
+#include <linux/blkdev.h>
#include <linux/gfs2_ondisk.h>
#include <linux/crc32.h>
@@ -427,12 +428,14 @@
{
struct gfs2_inode *ip = GFS2_I(inode);
struct gfs2_sbd *sdp = GFS2_SB(inode);
+ struct super_block *sb = sdp->sd_vfs;
struct buffer_head *dibh = mp->mp_bh[0];
u64 bn, dblock = 0;
unsigned n, i, blks, alloced = 0, iblks = 0, branch_start = 0;
unsigned dblks = 0;
unsigned ptrs_per_blk;
const unsigned end_of_metadata = height - 1;
+ int ret;
int eob = 0;
enum alloc_state state;
__be64 *ptr;
@@ -535,6 +538,15 @@
dblock = bn;
while (n-- > 0)
*ptr++ = cpu_to_be64(bn++);
+ if (buffer_zeronew(bh_map)) {
+ ret = sb_issue_zeroout(sb, dblock, dblks,
+ GFP_NOFS);
+ if (ret) {
+ fs_err(sdp,
+ "Failed to zero data buffers\n");
+ clear_buffer_zeronew(bh_map);
+ }
+ }
break;
}
} while ((state != ALLOC_DATA) || !dblock);