pNFS: Return RW layouts on OPEN_DOWNGRADE

If the client holds no more writeable open state, and does not hold a
write delegation, then send a layoutreturn as part of the OPEN_DOWNGRADE.

We do this only for writes, since some layout drivers may require you to
also hold a read layout if you are doing a R/W workload.

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
This commit is contained in:
Trond Myklebust 2016-11-21 10:56:38 -05:00
parent b6808145ad
commit e71708d4df

View File

@ -1251,6 +1251,7 @@ bool pnfs_roc(struct inode *ino,
nfs4_stateid stateid;
enum pnfs_iomode iomode = 0;
bool layoutreturn = false, roc = false;
bool skip_read = false;
if (!nfs_have_layout(ino))
return false;
@ -1270,18 +1271,27 @@ retry:
}
/* no roc if we hold a delegation */
if (nfs4_check_delegation(ino, FMODE_READ))
goto out_noroc;
if (nfs4_check_delegation(ino, FMODE_READ)) {
if (nfs4_check_delegation(ino, FMODE_WRITE))
goto out_noroc;
skip_read = true;
}
list_for_each_entry(ctx, &nfsi->open_files, list) {
state = ctx->state;
if (state == NULL)
continue;
/* Don't return layout if there is open file state */
if (state != NULL && state->state != 0)
if (state->state & FMODE_WRITE)
goto out_noroc;
if (state->state & FMODE_READ)
skip_read = true;
}
list_for_each_entry_safe(lseg, next, &lo->plh_segs, pls_list) {
if (skip_read && lseg->pls_range.iomode == IOMODE_READ)
continue;
/* If we are sending layoutreturn, invalidate all valid lsegs */
if (!test_and_clear_bit(NFS_LSEG_ROC, &lseg->pls_flags))
continue;