pnfs-obj: Get rid of objlayout_{alloc,free}_io_state

This is part of moving objio_osd to use the ORE.

objlayout_io_state had two functions:
1. It was used in the error reporting mechanism at layout_return.
   This function is kept intact.
   (Later patch will rename objlayout_io_state => objlayout_io_res)
2. Carrier of rw io members into the objio_read/write_paglist API.
   This is removed in this patch.

The {r,w}data received from NFS are passed directly to the
objio_{read,write}_paglist API. The io_engine is now allocating
it's own IO state as part of the read/write. The minimal
functionality that was part of the generic allocation is passed
to the io_engine.

So part of this patch is rename of:
	ios->ol_state.foo => ios->foo

At objlayout_{read,write}_done an objlayout_io_state is passed that
denotes the result of the IO. (Hence the later name change).
If the IO is successful objlayout calls an objio_free_result() API
immediately (Which for objio_osd causes the release of the io_state).
If the IO ended in an error it is hanged onto until reported in
layout_return and is released later through the objio_free_result()
API. (All this is not new just renamed and cleaned)

Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

1 files changed, 31 insertions, 93 deletions

diff --git a/fs/nfs/objlayout/objlayout.c b/fs/nfs/objlayout/objlayout.c
index 99c807df11dc..a82053ae5595 100644
--- a/fs/nfs/objlayout/objlayout.c
+++ b/fs/nfs/objlayout/objlayout.c
@@ -156,59 +156,23 @@ last_byte_offset(u64 start, u64 len)
         return end > start ? end - 1 : NFS4_MAX_UINT64;
 }
 
-static struct objlayout_io_state *
-objlayout_alloc_io_state(struct pnfs_layout_hdr *pnfs_layout_type,
-                        struct page **pages,
-                        unsigned pgbase,
-                        loff_t offset,
-                        size_t count,
-                        struct pnfs_layout_segment *lseg,
-                        void *rpcdata,
-                        gfp_t gfp_flags)
+void _fix_verify_io_params(struct pnfs_layout_segment *lseg,
+                           struct page ***p_pages, unsigned *p_pgbase,
+                           u64 offset, unsigned long count)
 {
-        struct objlayout_io_state *state;
         u64 lseg_end_offset;
 
-        dprintk("%s: allocating io_state\n", __func__);
-        if (objio_alloc_io_state(lseg, &state, gfp_flags))
-                return NULL;
-
         BUG_ON(offset < lseg->pls_range.offset);
         lseg_end_offset = end_offset(lseg->pls_range.offset,
                                      lseg->pls_range.length);
         BUG_ON(offset >= lseg_end_offset);
-        if (offset + count > lseg_end_offset) {
-                count = lseg->pls_range.length -
-                                (offset - lseg->pls_range.offset);
-                dprintk("%s: truncated count %Zd\n", __func__, count);
-        }
+        WARN_ON(offset + count > lseg_end_offset);
 
-        if (pgbase > PAGE_SIZE) {
-                pages += pgbase >> PAGE_SHIFT;
-                pgbase &= ~PAGE_MASK;
+        if (*p_pgbase > PAGE_SIZE) {
+                dprintk("%s: pgbase(0x%x) > PAGE_SIZE\n", __func__, *p_pgbase);
+                *p_pages += *p_pgbase >> PAGE_SHIFT;
+                *p_pgbase &= ~PAGE_MASK;
         }
-
-        INIT_LIST_HEAD(&state->err_list);
-        state->lseg = lseg;
-        state->rpcdata = rpcdata;
-        state->pages = pages;
-        state->pgbase = pgbase;
-        state->nr_pages = (pgbase + count + PAGE_SIZE - 1) >> PAGE_SHIFT;
-        state->offset = offset;
-        state->count = count;
-        state->sync = 0;
-
-        return state;
-}
-
-static void
-objlayout_free_io_state(struct objlayout_io_state *state)
-{
-        dprintk("%s: freeing io_state\n", __func__);
-        if (unlikely(!state))
-                return;
-
-        objio_free_io_state(state);
 }
 
 /*
@@ -217,12 +181,10 @@ objlayout_free_io_state(struct objlayout_io_state *state)
 static void
 objlayout_iodone(struct objlayout_io_state *state)
 {
-        dprintk("%s: state %p status\n", __func__, state);
-
         if (likely(state->status >= 0)) {
-                objlayout_free_io_state(state);
+                objio_free_result(state);
         } else {
-                struct objlayout *objlay = OBJLAYOUT(state->lseg->pls_layout);
+                struct objlayout *objlay = state->objlay;
 
                 spin_lock(&objlay->lock);
                 objlay->delta_space_valid = OBJ_DSU_INVALID;
@@ -289,15 +251,15 @@ objlayout_read_done(struct objlayout_io_state *state, ssize_t status, bool sync)
 {
         struct nfs_read_data *rdata = state->rpcdata;
 
-        state->status = status;
-        dprintk("%s: Begin status=%zd eof=%d\n", __func__,
-                status, rdata->res.eof);
-        rdata->task.tk_status = status;
+        state->status = rdata->task.tk_status = status;
         if (status >= 0)
                 rdata->res.count = status;
         objlayout_iodone(state);
         /* must not use state after this point */
 
+        dprintk("%s: Return status=%zd eof=%d sync=%d\n", __func__,
+                status, rdata->res.eof, sync);
+
         if (sync)
                 pnfs_ld_read_done(rdata);
         else {
@@ -314,7 +276,6 @@ objlayout_read_pagelist(struct nfs_read_data *rdata)
 {
         loff_t offset = rdata->args.offset;
         size_t count = rdata->args.count;
-        struct objlayout_io_state *state;
         int err;
         loff_t eof;
 
@@ -331,20 +292,14 @@ objlayout_read_pagelist(struct nfs_read_data *rdata)
         }
 
         rdata->res.eof = (offset + count) >= eof;
+        _fix_verify_io_params(rdata->lseg, &rdata->args.pages,
+                              &rdata->args.pgbase,
+                              rdata->args.offset, rdata->args.count);
 
-        state = objlayout_alloc_io_state(NFS_I(rdata->inode)->layout,
-                                         rdata->args.pages, rdata->args.pgbase,
-                                         offset, count,
-                                         rdata->lseg, rdata,
-                                         GFP_KERNEL);
-        if (unlikely(!state)) {
-                err = -ENOMEM;
-                goto out;
-        }
         dprintk("%s: inode(%lx) offset 0x%llx count 0x%Zx eof=%d\n",
                 __func__, rdata->inode->i_ino, offset, count, rdata->res.eof);
 
-        err = objio_read_pagelist(state);
+        err = objio_read_pagelist(rdata);
  out:
         if (unlikely(err)) {
                 rdata->pnfs_error = err;
@@ -374,23 +329,18 @@ void
 objlayout_write_done(struct objlayout_io_state *state, ssize_t status,
                      bool sync)
 {
-        struct nfs_write_data *wdata;
+        struct nfs_write_data *wdata = state->rpcdata;
 
-        dprintk("%s: Begin\n", __func__);
-        wdata = state->rpcdata;
-        state->status = status;
-        wdata->task.tk_status = status;
+        state->status = wdata->task.tk_status = status;
         if (status >= 0) {
                 wdata->res.count = status;
                 wdata->verf.committed = state->committed;
-                dprintk("%s: Return status %d committed %d\n",
-                        __func__, wdata->task.tk_status,
-                        wdata->verf.committed);
-        } else
-                dprintk("%s: Return status %d\n",
-                        __func__, wdata->task.tk_status);
+        }
         objlayout_iodone(state);
-        /* must not use state after this point */
+        /* must not use oir after this point */
+
+        dprintk("%s: Return status %zd committed %d sync=%d\n", __func__,
+                status, wdata->verf.committed, sync);
 
         if (sync)
                 pnfs_ld_write_done(wdata);
@@ -407,25 +357,13 @@ enum pnfs_try_status
 objlayout_write_pagelist(struct nfs_write_data *wdata,
                          int how)
 {
-        struct objlayout_io_state *state;
         int err;
 
-        state = objlayout_alloc_io_state(NFS_I(wdata->inode)->layout,
-                                         wdata->args.pages,
-                                         wdata->args.pgbase,
-                                         wdata->args.offset,
-                                         wdata->args.count,
-                                         wdata->lseg, wdata,
-                                         GFP_NOFS);
-        if (unlikely(!state)) {
-                err = -ENOMEM;
-                goto out;
-        }
+        _fix_verify_io_params(wdata->lseg, &wdata->args.pages,
+                              &wdata->args.pgbase,
+                              wdata->args.offset, wdata->args.count);
 
-        state->sync = how & FLUSH_SYNC;
-
-        err = objio_write_pagelist(state, how & FLUSH_STABLE);
- out:
+        err = objio_write_pagelist(wdata, how);
         if (unlikely(err)) {
                 wdata->pnfs_error = err;
                 dprintk("%s: Returned Error %d\n", __func__, err);
@@ -564,7 +502,7 @@ encode_accumulated_error(struct objlayout *objlay, __be32 *p)
                         merge_ioerr(&accumulated_err, ioerr);
                 }
                 list_del(&state->err_list);
-                objlayout_free_io_state(state);
+                objio_free_result(state);
         }
 
         pnfs_osd_xdr_encode_ioerr(p, &accumulated_err);
@@ -632,7 +570,7 @@ objlayout_encode_layoutreturn(struct pnfs_layout_hdr *pnfslay,
                         goto loop_done;
                 }
                 list_del(&state->err_list);
-                objlayout_free_io_state(state);
+                objio_free_result(state);
         }
 loop_done:
         spin_unlock(&objlay->lock);