| From | Greg Kroah-Hartman <> | Subject | [ 045/123] NFS: Dont use SetPageError in the NFS writeback code | Date | Wed, 9 Jan 2013 12:34:44 -0800 |
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3.7-stable review patch. If anyone has any objections, please let me know.
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From: Trond Myklebust <Trond.Myklebust@netapp.com>
commit ada8e20d044c0fa5610e504ce6fb4578ebd3edd9 upstream.
The writeback code is already capable of passing errors back to user space by means of the open_context->error. In the case of ENOSPC, Neil Brown is reporting seeing 2 errors being returned.
Neil writes:
"e.g. if /mnt2/ if an nfs mounted filesystem that has no space then
strace dd if=/dev/zero conv=fsync >> /mnt2/afile count=1
reported Input/output error and the relevant parts of the strace output are:
write(1, "\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0"..., 512) = 512 fsync(1) = -1 EIO (Input/output error) close(1) = -1 ENOSPC (No space left on device)"
Neil then shows that the duplication of error messages appears to be due to the use of the PageError() mechanism, which causes filemap_fdatawait_range to return the extra EIO. The regression was introduced by commit 7b281ee026552f10862b617a2a51acf49c829554 (NFS: fsync() must exit with an error if page writeback failed).
Fix this by removing the call to SetPageError(), and just relying on open_context->error reporting the ENOSPC back to fsync().
Reported-by: Neil Brown <neilb@suse.de> Tested-by: Neil Brown <neilb@suse.de> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
--- fs/nfs/write.c | 1 - 1 file changed, 1 deletion(-)
--- a/fs/nfs/write.c +++ b/fs/nfs/write.c @@ -202,7 +202,6 @@ out: /* A writeback failed: mark the page as bad, and invalidate the page cache */ static void nfs_set_pageerror(struct page *page) { - SetPageError(page); nfs_zap_mapping(page_file_mapping(page)->host, page_file_mapping(page)); }
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