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authorTrond Myklebust <trond.myklebust@primarydata.com>2017-04-25 11:26:53 -0400
committerTrond Myklebust <trond.myklebust@primarydata.com>2017-04-25 15:42:34 -0400
commit6aeafd05eca9bc8ab6b03d7e56d09ffd18190f44 (patch)
tree4cdc02f84e2246efef3fe50dfb138e9cff9aeadd /fs/nfs
parentb3230e80a6d115d2eb50fe3f4794ad04d84766de (diff)
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>
Diffstat (limited to 'fs/nfs')
-rw-r--r--fs/nfs/pnfs.c16
1 files changed, 13 insertions, 3 deletions
diff --git a/fs/nfs/pnfs.c b/fs/nfs/pnfs.c
index 634adb3f8524..eff266ea813c 100644
--- a/fs/nfs/pnfs.c
+++ b/fs/nfs/pnfs.c
@@ -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)