From: Joseph Qi <joseph.qi@xxxxxxxxxxxxxxxxx> Subject: ocfs2: clearly handle ocfs2_grab_pages_for_write() return value ocfs2_grab_pages_for_write() may return -EAGAIN if write context type is mmap and it could not lock the target page. In this case, we exit with no error and no target page. And then trigger the caller page_mkwrite() to retry. Since there are other caller types, e.g. buffer and direct io, make the return value handling more clear. Link: https://lkml.kernel.org/r/20211206065051.103353-1-joseph.qi@xxxxxxxxxxxxxxxxx Signed-off-by: Joseph Qi <joseph.qi@xxxxxxxxxxxxxxxxx> Reported-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx> Cc: Mark Fasheh <mark@xxxxxxxxxx> Cc: Joel Becker <jlbec@xxxxxxxxxxxx> Cc: Junxiao Bi <junxiao.bi@xxxxxxxxxx> Cc: Changwei Ge <gechangwei@xxxxxxx> Cc: Gang He <ghe@xxxxxxxx> Cc: Jun Piao <piaojun@xxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- fs/ocfs2/aops.c | 26 +++++++++++++------------- 1 file changed, 13 insertions(+), 13 deletions(-) --- a/fs/ocfs2/aops.c~ocfs2-clearly-handle-ocfs2_grab_pages_for_write-return-value +++ a/fs/ocfs2/aops.c @@ -1799,20 +1799,20 @@ try_again: */ ret = ocfs2_grab_pages_for_write(mapping, wc, wc->w_cpos, pos, len, cluster_of_pages, mmap_page); - if (ret && ret != -EAGAIN) { - mlog_errno(ret); - goto out_quota; - } + if (ret) { + /* + * ocfs2_grab_pages_for_write() returns -EAGAIN if it could not lock + * the target page. In this case, we exit with no error and no target + * page. This will trigger the caller, page_mkwrite(), to re-try + * the operation. + */ + if (type == OCFS2_WRITE_MMAP && ret == -EAGAIN) { + BUG_ON(wc->w_target_page); + ret = 0; + goto out_quota; + } - /* - * ocfs2_grab_pages_for_write() returns -EAGAIN if it could not lock - * the target page. In this case, we exit with no error and no target - * page. This will trigger the caller, page_mkwrite(), to re-try - * the operation. - */ - if (ret == -EAGAIN) { - BUG_ON(wc->w_target_page); - ret = 0; + mlog_errno(ret); goto out_quota; } _
