Btrfs: don't ignore compressed bio write errors

Our compressed bio write end callback was essentially ignoring the error
parameter. When a write error happens, it must pass a value of 0 to the
inode's write_page_end_io_hook callback, SetPageError on the respective
pages and set AS_EIO in the inode's mapping flags, so that a call to
filemap_fdatawait_range() / filemap_fdatawait() can find out that errors
happened (we surely don't want silent failures on fsync for example).

Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Chris Mason <clm@fb.com>

diff --git a/fs/btrfs/compression.c b/fs/btrfs/compression.c
index d3220d31d3cbf0e653898d15816f5895045c06d5..1bf411bc28fd5c09a1c8f516bfd2c7b618495bfb 100644 (file)
--- a/fs/btrfs/compression.c
+++ b/fs/btrfs/compression.c
@@ -224,16 +224,19 @@ out:
  * Clear the writeback bits on all of the file
  * pages for a compressed write
  */
-static noinline void end_compressed_writeback(struct inode *inode, u64 start,
-                                             unsigned long ram_size)
+static noinline void end_compressed_writeback(struct inode *inode,
+                                             const struct compressed_bio *cb)
 {
-       unsigned long index = start >> PAGE_CACHE_SHIFT;
-       unsigned long end_index = (start + ram_size - 1) >> PAGE_CACHE_SHIFT;
+       unsigned long index = cb->start >> PAGE_CACHE_SHIFT;
+       unsigned long end_index = (cb->start + cb->len - 1) >> PAGE_CACHE_SHIFT;
        struct page *pages[16];
        unsigned long nr_pages = end_index - index + 1;
        int i;
        int ret;
 
+       if (cb->errors)
+               mapping_set_error(inode->i_mapping, -EIO);
+
        while (nr_pages > 0) {
                ret = find_get_pages_contig(inode->i_mapping, index,
                                     min_t(unsigned long,
@@ -244,6 +247,8 @@ static noinline void end_compressed_writeback(struct inode *inode, u64 start,
                        continue;
                }
                for (i = 0; i < ret; i++) {
+                       if (cb->errors)
+                               SetPageError(pages[i]);
                        end_page_writeback(pages[i]);
                        page_cache_release(pages[i]);
                }
@@ -287,10 +292,11 @@ static void end_compressed_bio_write(struct bio *bio, int err)
        tree->ops->writepage_end_io_hook(cb->compressed_pages[0],
                                         cb->start,
                                         cb->start + cb->len - 1,
-                                        NULL, 1);
+                                        NULL,
+                                        err ? 0 : 1);
        cb->compressed_pages[0]->mapping = NULL;
 
-       end_compressed_writeback(inode, cb->start, cb->len);
+       end_compressed_writeback(inode, cb);
        /* note, our inode could be gone now */
 
        /*