50 lines
1.5 KiB
Plaintext
50 lines
1.5 KiB
Plaintext
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From: mason@suse.de
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Subject: make sure O_SYNC writes properly return -EIO
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References: bnc#58622
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Make sure to honor the error status of synchronous writeback during
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O_SYNC writes
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Acked-by: Jeff Mahoney <jeffm@suse.com>
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---
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mm/filemap.c | 17 +++++++++++++++--
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1 file changed, 15 insertions(+), 2 deletions(-)
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--- a/mm/filemap.c
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+++ b/mm/filemap.c
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@@ -2325,7 +2325,7 @@ generic_file_buffered_write(struct kiocb
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if (likely(status >= 0)) {
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written += status;
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- *ppos = pos + status;
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+ pos += status;
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/*
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* For now, when the user asks for O_SYNC, we'll actually give
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@@ -2343,10 +2343,23 @@ generic_file_buffered_write(struct kiocb
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* to buffered writes (block instantiation inside i_size). So we sync
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* the file data here, to try to honour O_DIRECT expectations.
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*/
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- if (unlikely(file->f_flags & O_DIRECT) && written)
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+ if (unlikely(file->f_flags & O_DIRECT) && status >= 0 && written)
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status = filemap_write_and_wait_range(mapping,
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pos, pos + written - 1);
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+ /*
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+ * We must let know userspace if something hasn't been written
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+ * correctly. If we got an I/O error it means we got an hardware
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+ * failure, anything can be happening to the on-disk data,
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+ * letting know userspace that a bit of data might have been
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+ * written correctly on disk is a very low priority, compared
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+ * to letting know userspace that some data has _not_ been
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+ * written at all.
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+ */
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+ if (unlikely(status == -EIO))
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+ return status;
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+ *ppos = pos;
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+
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return written ? written : status;
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}
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EXPORT_SYMBOL(generic_file_buffered_write);
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