From: Darrick J. Wong <djwong@xxxxxxxxxx>
Not sure why block device targets don't get O_DIRECT in !buffered mode,
but it's misleading when the copy completes instantly only to stall
forever due to fsync-on-close. Adjust the "write last sector" code to
allocate a properly aligned buffer.
In removing the onstack buffer for EOD writes, this also corrects the
buffer being larger than necessary -- the old code declared an array of
32768 pointers, whereas all we really need is an aligned 32768-byte
buffer.
Signed-off-by: Darrick J. Wong <djwong@xxxxxxxxxx>
---
copy/xfs_copy.c | 12 ++++++------
1 file changed, 6 insertions(+), 6 deletions(-)
diff --git a/copy/xfs_copy.c b/copy/xfs_copy.c
index d9a14a95..bcc807ed 100644
--- a/copy/xfs_copy.c
+++ b/copy/xfs_copy.c
@@ -832,13 +832,9 @@ main(int argc, char **argv)
do_out(_("Creating file %s\n"), target[i].name);
open_flags |= O_CREAT;
- if (!buffered_output)
- open_flags |= O_DIRECT;
write_last_block = 1;
} else if (S_ISREG(statbuf.st_mode)) {
open_flags |= O_TRUNC;
- if (!buffered_output)
- open_flags |= O_DIRECT;
write_last_block = 1;
} else {
/*
@@ -855,6 +851,8 @@ main(int argc, char **argv)
exit(1);
}
}
+ if (!buffered_output)
+ open_flags |= O_DIRECT;
target[i].fd = open(target[i].name, open_flags, 0644);
if (target[i].fd < 0) {
@@ -887,14 +885,15 @@ main(int argc, char **argv)
}
}
} else {
- char *lb[XFS_MAX_SECTORSIZE] = { NULL };
+ char *lb = memalign(wbuf_align, XFS_MAX_SECTORSIZE);
off64_t off;
ssize_t len;
/* ensure device files are sufficiently large */
+ memset(lb, 0, XFS_MAX_SECTORSIZE);
off = mp->m_sb.sb_dblocks * source_blocksize;
- off -= sizeof(lb);
+ off -= XFS_MAX_SECTORSIZE;
len = pwrite(target[i].fd, lb, XFS_MAX_SECTORSIZE, off);
if (len < 0) {
do_log(_("%s: failed to write last block\n"),
@@ -911,6 +910,7 @@ main(int argc, char **argv)
target[i].name);
exit(1);
}
+ free(lb);
}
}
