FUSE has an architectural peculiarity: it cannot write to an inode, unless it has an associated file open for write. Since the beginning (Apr 30 2008, commit 3be5a52b), FUSE BUG_ON (later WARN_ON) the case when it has to process writeback, but all associated files are closed. The latest relevant commit is 72523425:
> Don't bug if there's no writable files found for page writeback. If ever > this is triggered, a WARN_ON helps debugging it much better then a BUG_ON. > > Signed-off-by: Miklos Szeredi <[email protected]> But that situation can happen in quite a legal way: for example, let's mmap a file, then issue O_DIRECT read to mmapped region and immediately close file and munmap. O_DIRECT will pin some pages, execute IO to them and then mark pages dirty. Here we are. Signed-off-by: Maxim Patlasov <[email protected]> --- fs/fuse/file.c | 14 +++----------- 1 file changed, 3 insertions(+), 11 deletions(-) diff --git a/fs/fuse/file.c b/fs/fuse/file.c index 6e16dad..3a47aa2 100644 --- a/fs/fuse/file.c +++ b/fs/fuse/file.c @@ -1624,8 +1624,8 @@ static void fuse_writepage_end(struct fuse_conn *fc, struct fuse_req *req) fuse_writepage_free(fc, req); } -static struct fuse_file *__fuse_write_file_get(struct fuse_conn *fc, - struct fuse_inode *fi) +static struct fuse_file *fuse_write_file_get(struct fuse_conn *fc, + struct fuse_inode *fi) { struct fuse_file *ff = NULL; @@ -1640,14 +1640,6 @@ static struct fuse_file *__fuse_write_file_get(struct fuse_conn *fc, return ff; } -static struct fuse_file *fuse_write_file_get(struct fuse_conn *fc, - struct fuse_inode *fi) -{ - struct fuse_file *ff = __fuse_write_file_get(fc, fi); - WARN_ON(!ff); - return ff; -} - int fuse_write_inode(struct inode *inode, struct writeback_control *wbc) { struct fuse_conn *fc = get_fuse_conn(inode); @@ -1655,7 +1647,7 @@ int fuse_write_inode(struct inode *inode, struct writeback_control *wbc) struct fuse_file *ff; int err; - ff = __fuse_write_file_get(fc, fi); + ff = fuse_write_file_get(fc, fi); err = fuse_flush_times(inode, ff); if (ff) fuse_file_put(ff, 0); -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
