@@ -376,17 +376,16 @@ 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) &&
@@ -403,14 +402,11 @@ 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;
}
/**
@@ -430,14 +426,8 @@ static int __filemap_fdatawait_range(struct address_space *mapping,
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);
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> --- mm/filemap.c | 20 +++++--------------- 1 file changed, 5 insertions(+), 15 deletions(-)