From patchwork Fri Nov 18 12:09:36 2011 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Subject: [Cluster-devel] fallocate vs O_(D)SYNC From: Steven Whitehouse X-Patchwork-Id: 126398 Message-Id: <1321618176.2729.33.camel@menhir> To: Jan Kara Cc: Christoph Hellwig , linux-btrfs@vger.kernel.org, linux-ext4@vger.kernel.org, mfasheh@suse.com, jlbec@evilplan.org, cluster-devel@redhat.com Date: Fri, 18 Nov 2011 12:09:36 +0000 Hi, Here is what I'm planning for GFS2: Add sync of metadata after fallocate for O_SYNC files to ensure that we meet expectations for everything being on disk in this case. Unfortunately, the offset and len parameters are modified during the course of the fallocate function, so I've had to add a couple of new variables to call generic_write_sync() at the end. I know that potentially this will sync data as well within the range, but I think that is a fairly harmless side-effect overall, since we would not normally expect there to be any dirty data within the range in question. Signed-off-by: Steven Whitehouse Cc: Christoph Hellwig Cc: Benjamin Marzinski --- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html diff --git a/fs/gfs2/file.c b/fs/gfs2/file.c index 6336bc6..9b6c6ac 100644 --- a/fs/gfs2/file.c +++ b/fs/gfs2/file.c @@ -752,6 +752,8 @@ static long gfs2_fallocate(struct file *file, int mode, loff_t offset, loff_t bytes, max_bytes; struct gfs2_alloc *al; int error; + const loff_t pos = offset; + const loff_t count = len; loff_t bsize_mask = ~((loff_t)sdp->sd_sb.sb_bsize - 1); loff_t next = (offset + len - 1) >> sdp->sd_sb.sb_bsize_shift; loff_t max_chunk_size = UINT_MAX & bsize_mask; @@ -834,6 +836,9 @@ retry: gfs2_quota_unlock(ip); gfs2_alloc_put(ip); } + + if (error == 0) + error = generic_write_sync(file, pos, count); goto out_unlock; out_trans_fail: