[51/90] ext4: retry failed direct IO allocations

Greg KH
2009-12-11T04:40:42Z

[-- Attachment #1: 0051-ext4-retry-failed-direct-IO-allocations.patch --]
[-- Type: text/plain, Size: 1303 bytes --]

2.6.31-stable review patch. If anyone has any objections, please let us know.

------------------
(cherry picked from commit fbbf69456619de5d251cb9f1df609069178c62d5)

On a 256M filesystem, doing this in a loop:

xfs_io -F -f -d -c 'pwrite 0 64m' test
rm -f test

eventually leads to ENOSPC. (the xfs_io command does a
64m direct IO write to the file "test")

As with other block allocation callers, it looks like we need to
potentially retry the allocations on the initial ENOSPC.

Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
---
fs/ext4/inode.c | 4 ++++
1 file changed, 4 insertions(+)

--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -3372,6 +3372,7 @@ static ssize_t ext4_ind_direct_IO(int rw
ssize_t ret;
int orphan = 0;
size_t count = iov_length(iov, nr_segs);
+ int retries = 0;

if (rw == WRITE) {
loff_t final_size = offset + count;
@@ -3394,9 +3395,12 @@ static ssize_t ext4_ind_direct_IO(int rw
}
}

+retry:
ret = blockdev_direct_IO(rw, iocb, inode, inode->i_sb->s_bdev, iov,
offset, nr_segs,
ext4_get_block, NULL);
+ if (ret == -ENOSPC && ext4_should_retry_alloc(inode->i_sb, &retries))
+ goto retry;

if (orphan) {
int err;