fuse: fuse_flush must check mapping->flags for errors

PATCH Applied Maxim Patlasov 2 participants 2 messages Jul 20, 2016 – Jul 21, 2016

Subsystems (2)

VFS FUSE filesystem core

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Maxim Patlasov

author

2016-07-20 09:45 UTC #0 lore raw

PATCH v2 1/1 fuse: fuse_flush must check mapping->flags for errors

fuse_flush() calls write_inode_now() that triggers writeback, but actual writeback will happen later, on fuse_sync_writes(). If an error happens, fuse_writepage_end() will set error bit in mapping->flags. So, we have to check mapping->flags after fuse_sync_writes().

Changed in v2:
- fixed silly type: check must be *after* fuse_sync_writes()

Signed-off-by Maxim Patlasov <[email protected]>

---
 fs/fuse/file.c |    9 +++++++++
 1 file changed, 9 insertions(+)

fs/fuse/file.c +9 -0

index ad1da83..6cac3dc 100644
@@ -417,6 +417,15 @@ static int fuse_flush(struct file *file, fl_owner_t id)
 	fuse_sync_writes(inode);
 	inode_unlock(inode);
 
+	if (test_bit(AS_ENOSPC, &file->f_mapping->flags) &&
+	    test_and_clear_bit(AS_ENOSPC, &file->f_mapping->flags))
+		err = -ENOSPC;
+	if (test_bit(AS_EIO, &file->f_mapping->flags) &&
+	    test_and_clear_bit(AS_EIO, &file->f_mapping->flags))
+		err = -EIO;
+	if (err)
+		return err;
+
 	req = fuse_get_req_nofail_nopages(fc, file);
 	memset(&inarg, 0, sizeof(inarg));
 	inarg.fh = ff->fh;

Miklos Szeredi

maintainer Applied

2016-07-21 10:28 UTC #1 lore raw

Quoted 7 lines · Maxim Patlasov

fuse_flush() calls write_inode_now() that triggers writeback, but actual writeback will happen later, on fuse_sync_writes(). If an error happens, fuse_writepage_end() will set error bit in mapping->flags. So, we have to check mapping->flags after fuse_sync_writes().
Changed in v2:
- fixed silly type: check must be *after* fuse_sync_writes()

I applied both with a cleanup patch at the end to use the filemap_check_errors() helper, which does exactly this.

Thanks,
Miklos