pNFS: Fix use after free issues in pnfs_do_read()

The assumption should be that if the caller returns PNFS_ATTEMPTED, then hdr
has been consumed, and so we should not be testing hdr->task.tk_status.
If the caller returns PNFS_TRY_AGAIN, then we need to recoalesce and
free hdr.

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
This commit is contained in:
Trond Myklebust 2017-04-25 11:26:53 -04:00
parent b3230e80a6
commit 6aeafd05ec

View File

@ -2419,10 +2419,20 @@ pnfs_do_read(struct nfs_pageio_descriptor *desc, struct nfs_pgio_header *hdr)
enum pnfs_try_status trypnfs;
trypnfs = pnfs_try_to_read_data(hdr, call_ops, lseg);
if (trypnfs == PNFS_TRY_AGAIN)
pnfs_read_resend_pnfs(hdr);
if (trypnfs == PNFS_NOT_ATTEMPTED || hdr->task.tk_status)
switch (trypnfs) {
case PNFS_NOT_ATTEMPTED:
pnfs_read_through_mds(desc, hdr);
case PNFS_ATTEMPTED:
break;
case PNFS_TRY_AGAIN:
/* cleanup hdr and prepare to redo pnfs */
if (!test_and_set_bit(NFS_IOHDR_REDO, &hdr->flags)) {
struct nfs_pgio_mirror *mirror = nfs_pgio_current_mirror(desc);
list_splice_init(&hdr->pages, &mirror->pg_list);
mirror->pg_recoalesce = 1;
}
hdr->mds_ops->rpc_release(hdr);
}
}
static void pnfs_readhdr_free(struct nfs_pgio_header *hdr)