pNFS/flexfiles: Don't prevent flexfiles client from retrying LAYOUTGET

Fix a bug in which flexfiles clients are falling back to I/O through the
MDS even when the FF_FLAGS_NO_IO_THRU_MDS flag is set.

The flexfiles client will always report errors through the LAYOUTRETURN
and/or LAYOUTERROR mechanisms, so it should normally be safe for it
to retry the LAYOUTGET until it fails or succeeds.

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>

diff --git a/fs/nfs/flexfilelayout/flexfilelayout.c b/fs/nfs/flexfilelayout/flexfilelayout.c
index 5ede5c2..1da19d7 100644 (file)
--- a/fs/nfs/flexfilelayout/flexfilelayout.c
+++ b/fs/nfs/flexfilelayout/flexfilelayout.c
@@ -1399,11 +1399,9 @@ static int ff_layout_write_done_cb(struct rpc_task *task,
 
        switch (err) {
        case -NFS4ERR_RESET_TO_PNFS:
-               pnfs_set_retry_layoutget(hdr->lseg->pls_layout);
                ff_layout_reset_write(hdr, true);
                return task->tk_status;
        case -NFS4ERR_RESET_TO_MDS:
-               pnfs_clear_retry_layoutget(hdr->lseg->pls_layout);
                ff_layout_reset_write(hdr, false);
                return task->tk_status;
        case -EAGAIN:
@@ -1438,11 +1436,9 @@ static int ff_layout_commit_done_cb(struct rpc_task *task,
 
        switch (err) {
        case -NFS4ERR_RESET_TO_PNFS:
-               pnfs_set_retry_layoutget(data->lseg->pls_layout);
                pnfs_generic_prepare_to_resend_writes(data);
                return -EAGAIN;
        case -NFS4ERR_RESET_TO_MDS:
-               pnfs_clear_retry_layoutget(data->lseg->pls_layout);
                pnfs_generic_prepare_to_resend_writes(data);
                return -EAGAIN;
        case -EAGAIN:

diff --git a/fs/nfs/flexfilelayout/flexfilelayoutdev.c b/fs/nfs/flexfilelayout/flexfilelayoutdev.c
index e125e55..bd03275 100644 (file)
--- a/fs/nfs/flexfilelayout/flexfilelayoutdev.c
+++ b/fs/nfs/flexfilelayout/flexfilelayoutdev.c
@@ -429,22 +429,14 @@ nfs4_ff_layout_prepare_ds(struct pnfs_layout_segment *lseg, u32 ds_idx,
                                         mirror, lseg->pls_range.offset,
                                         lseg->pls_range.length, NFS4ERR_NXIO,
                                         OP_ILLEGAL, GFP_NOIO);
-               if (fail_return) {
-                       pnfs_error_mark_layout_for_return(ino, lseg);
-                       if (ff_layout_has_available_ds(lseg))
-                               pnfs_set_retry_layoutget(lseg->pls_layout);
-                       else
-                               pnfs_clear_retry_layoutget(lseg->pls_layout);
-
-               } else {
+               if (!fail_return) {
                        if (ff_layout_has_available_ds(lseg))
                                set_bit(NFS_LAYOUT_RETURN_BEFORE_CLOSE,
                                        &lseg->pls_layout->plh_flags);
-                       else {
+                       else
                                pnfs_error_mark_layout_for_return(ino, lseg);
-                               pnfs_clear_retry_layoutget(lseg->pls_layout);
-                       }
-               }
+               } else
+                       pnfs_error_mark_layout_for_return(ino, lseg);
        }
 out_update_creds:
        if (ff_layout_update_mirror_cred(mirror, ds))

diff --git a/fs/nfs/pnfs.c b/fs/nfs/pnfs.c
index 580207b..6b42362 100644 (file)
--- a/fs/nfs/pnfs.c
+++ b/fs/nfs/pnfs.c
@@ -618,7 +618,6 @@ pnfs_destroy_layout(struct nfs_inode *nfsi)
                pnfs_get_layout_hdr(lo);
                pnfs_layout_clear_fail_bit(lo, NFS_LAYOUT_RO_FAILED);
                pnfs_layout_clear_fail_bit(lo, NFS_LAYOUT_RW_FAILED);
-               pnfs_clear_retry_layoutget(lo);
                spin_unlock(&nfsi->vfs_inode.i_lock);
                pnfs_free_lseg_list(&tmp_list);
                pnfs_put_layout_hdr(lo);
@@ -1094,7 +1093,6 @@ bool pnfs_roc(struct inode *ino)
                                   &lo->plh_flags))
                layoutreturn = pnfs_prepare_layoutreturn(lo);
 
-       pnfs_clear_retry_layoutget(lo);
        list_for_each_entry_safe(lseg, tmp, &lo->plh_segs, pls_list)
                /* If we are sending layoutreturn, invalidate all valid lsegs */
                if (layoutreturn || test_bit(NFS_LSEG_ROC, &lseg->pls_flags)) {
@@ -1457,25 +1455,15 @@ static bool pnfs_within_mdsthreshold(struct nfs_open_context *ctx,
        return ret;
 }
 
-/* stop waiting if someone clears NFS_LAYOUT_RETRY_LAYOUTGET bit. */
-static int pnfs_layoutget_retry_bit_wait(struct wait_bit_key *key, int mode)
-{
-       if (!test_bit(NFS_LAYOUT_RETRY_LAYOUTGET, key->flags))
-               return 1;
-       return nfs_wait_bit_killable(key, mode);
-}
-
 static bool pnfs_prepare_to_retry_layoutget(struct pnfs_layout_hdr *lo)
 {
-       if (!pnfs_should_retry_layoutget(lo))
-               return false;
        /*
         * send layoutcommit as it can hold up layoutreturn due to lseg
         * reference
         */
        pnfs_layoutcommit_inode(lo->plh_inode, false);
        return !wait_on_bit_action(&lo->plh_flags, NFS_LAYOUT_RETURN,
-                                  pnfs_layoutget_retry_bit_wait,
+                                  nfs_wait_bit_killable,
                                   TASK_UNINTERRUPTIBLE);
 }
 
@@ -1550,8 +1538,7 @@ lookup_again:
        }
 
        /* if LAYOUTGET already failed once we don't try again */
-       if (pnfs_layout_io_test_failed(lo, iomode) &&
-           !pnfs_should_retry_layoutget(lo)) {
+       if (pnfs_layout_io_test_failed(lo, iomode)) {
                trace_pnfs_update_layout(ino, pos, count, iomode, lo,
                                 PNFS_UPDATE_LAYOUT_IO_TEST_FAIL);
                goto out_unlock;
@@ -1628,7 +1615,6 @@ lookup_again:
                arg.length = PAGE_CACHE_ALIGN(arg.length);
 
        lseg = send_layoutget(lo, ctx, &arg, gfp_flags);
-       pnfs_clear_retry_layoutget(lo);
        atomic_dec(&lo->plh_outstanding);
        trace_pnfs_update_layout(ino, pos, count, iomode, lo,
                                 PNFS_UPDATE_LAYOUT_SEND_LAYOUTGET);

diff --git a/fs/nfs/pnfs.h b/fs/nfs/pnfs.h
index d1990e9..6916ff4 100644 (file)
--- a/fs/nfs/pnfs.h
+++ b/fs/nfs/pnfs.h
@@ -98,7 +98,6 @@ enum {
        NFS_LAYOUT_RETURN_BEFORE_CLOSE, /* Return this layout before close */
        NFS_LAYOUT_INVALID_STID,        /* layout stateid id is invalid */
        NFS_LAYOUT_FIRST_LAYOUTGET,     /* Serialize first layoutget */
-       NFS_LAYOUT_RETRY_LAYOUTGET,     /* Retry layoutget */
 };
 
 enum layoutdriver_policy_flags {
@@ -379,26 +378,6 @@ nfs4_get_deviceid(struct nfs4_deviceid_node *d)
        return d;
 }
 
-static inline void pnfs_set_retry_layoutget(struct pnfs_layout_hdr *lo)
-{
-       if (!test_and_set_bit(NFS_LAYOUT_RETRY_LAYOUTGET, &lo->plh_flags))
-               atomic_inc(&lo->plh_refcount);
-}
-
-static inline void pnfs_clear_retry_layoutget(struct pnfs_layout_hdr *lo)
-{
-       if (test_and_clear_bit(NFS_LAYOUT_RETRY_LAYOUTGET, &lo->plh_flags)) {
-               atomic_dec(&lo->plh_refcount);
-               /* wake up waiters for LAYOUTRETURN as that is not needed */
-               wake_up_bit(&lo->plh_flags, NFS_LAYOUT_RETURN);
-       }
-}
-
-static inline bool pnfs_should_retry_layoutget(struct pnfs_layout_hdr *lo)
-{
-       return test_bit(NFS_LAYOUT_RETRY_LAYOUTGET, &lo->plh_flags);
-}
-
 static inline struct pnfs_layout_segment *
 pnfs_get_lseg(struct pnfs_layout_segment *lseg)
 {