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author | 2017-07-06 07:02:24 -0400 | |
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committer | 2017-07-06 07:02:24 -0400 | |
commit | 5e8fcc1a0ffa0fb794b3c0efa2c3c7612a771c36 (patch) | |
tree | 2df735706ee4006f12f2ab77fd24e7ae019310fe /mm/filemap.c | |
parent | mm: clear AS_EIO/AS_ENOSPC when writeback initiation fails (diff) | |
download | linux-5e8fcc1a0ffa0fb794b3c0efa2c3c7612a771c36.tar.gz linux-5e8fcc1a0ffa0fb794b3c0efa2c3c7612a771c36.tar.bz2 linux-5e8fcc1a0ffa0fb794b3c0efa2c3c7612a771c36.zip |
mm: don't TestClearPageError in __filemap_fdatawait_range
The -EIO returned here can end up overriding whatever error is marked in
the address space, and be returned at fsync time, even when there is a
more appropriate error stored in the mapping.
Read errors are also sometimes tracked on a per-page level using
PG_error. Suppose we have a read error on a page, and then that page is
subsequently dirtied by overwriting the whole page. Writeback doesn't
clear PG_error, so we can then end up successfully writing back that
page and still return -EIO on fsync.
Worse yet, PG_error is cleared during a sync() syscall, but the -EIO
return from that is silently discarded. Any subsystem that is relying on
PG_error to report errors during fsync can easily lose writeback errors
due to this. All you need is a stray sync() call to wait for writeback
to complete and you've lost the error.
Since the handling of the PG_error flag is somewhat inconsistent across
subsystems, let's just rely on marking the address space when there are
writeback errors. Change the TestClearPageError call to ClearPageError,
and make __filemap_fdatawait_range a void return function.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Diffstat (limited to 'mm/filemap.c')
-rw-r--r-- | mm/filemap.c | 20 |
1 files changed, 5 insertions, 15 deletions
diff --git a/mm/filemap.c b/mm/filemap.c index 49bc9720fb00..eb99b5f23c61 100644 --- a/mm/filemap.c +++ b/mm/filemap.c @@ -386,17 +386,16 @@ int filemap_flush(struct address_space *mapping) } EXPORT_SYMBOL(filemap_flush); -static int __filemap_fdatawait_range(struct address_space *mapping, +static void __filemap_fdatawait_range(struct address_space *mapping, loff_t start_byte, loff_t end_byte) { pgoff_t index = start_byte >> PAGE_SHIFT; pgoff_t end = end_byte >> PAGE_SHIFT; struct pagevec pvec; int nr_pages; - int ret = 0; if (end_byte < start_byte) - goto out; + return; pagevec_init(&pvec, 0); while ((index <= end) && @@ -413,14 +412,11 @@ static int __filemap_fdatawait_range(struct address_space *mapping, continue; wait_on_page_writeback(page); - if (TestClearPageError(page)) - ret = -EIO; + ClearPageError(page); } pagevec_release(&pvec); cond_resched(); } -out: - return ret; } /** @@ -440,14 +436,8 @@ out: int filemap_fdatawait_range(struct address_space *mapping, loff_t start_byte, loff_t end_byte) { - int ret, ret2; - - ret = __filemap_fdatawait_range(mapping, start_byte, end_byte); - ret2 = filemap_check_errors(mapping); - if (!ret) - ret = ret2; - - return ret; + __filemap_fdatawait_range(mapping, start_byte, end_byte); + return filemap_check_errors(mapping); } EXPORT_SYMBOL(filemap_fdatawait_range); |