On Wed, Dec 23, 2020 at 07:48:52AM -0500, Jeff Layton wrote:

On Mon, 2020-12-21 at 14:50 -0500, Vivek Goyal wrote:

quoted

Right now we check for errors on super block in syncfs().

ret2 = errseq_check_and_advance(&sb->s_wb_err, &f.file->f_sb_err);

overlayfs does not update sb->s_wb_err and it is tracked on upper filesystem.
So provide a superblock operation to check errors so that filesystem
can provide override generic method and provide its own method to
check for writeback errors.

Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
---
 fs/sync.c          | 5 ++++-
 include/linux/fs.h | 1 +
 2 files changed, 5 insertions(+), 1 deletion(-)

diff --git a/fs/sync.c b/fs/sync.c
index b5fb83a734cd..57e43a16dfca 100644
--- a/fs/sync.c
+++ b/fs/sync.c

@@ -176,7 +176,10 @@ SYSCALL_DEFINE1(syncfs, int, fd)

 	ret = sync_filesystem(sb);
 	up_read(&sb->s_umount);
 

-	ret2 = errseq_check_and_advance(&sb->s_wb_err, &f.file->f_sb_err);
+	if (sb->s_op->errseq_check_advance)
+		ret2 = sb->s_op->errseq_check_advance(sb, f.file);
+	else
+		ret2 = errseq_check_and_advance(&sb->s_wb_err, &f.file->f_sb_err);
 

 	fdput(f);
 	return ret ? ret : ret2;

diff --git a/include/linux/fs.h b/include/linux/fs.h
index 8667d0cdc71e..4297b6127adf 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h

@@ -1965,6 +1965,7 @@ struct super_operations {

 				  struct shrink_control *);
 	long (*free_cached_objects)(struct super_block *,
 				    struct shrink_control *);
+	int (*errseq_check_advance)(struct super_block *, struct file *);
 };
 

 /*

Also, the other super_operations generally don't take a superblock
pointer when you pass in a different fs object pointer. This should
probably just take a struct file * and then the operation can chase
pointers to the superblock from there.

Ok, I will drop super_block * argument and just pass in "struct file *".

Vivek

 
-- 
Jeff Layton [off-list ref]