NFSv4.1: Clean ups and bugfixes for the pNFS read/writeback/commit code

Move more pnfs-isms out of the generic commit code.

Bugfixes:

- filelayout_scan_commit_lists doesn't need to get/put the lseg.
  In fact since it is run under the inode->i_lock, the lseg_put()
  can deadlock.

- Ensure that we distinguish between what needs to be done for
  commit-to-data server and what needs to be done for commit-to-MDS
  using the new flag PG_COMMIT_TO_DS. Otherwise we may end up calling
  put_lseg() on a bucket for a struct nfs_page that got written
  through the MDS.

- Fix a case where we were using list_del() on an nfs_page->wb_list
  instead of list_del_init().

- filelayout_initiate_commit needs to call filelayout_commit_release
  on error instead of the mds_ops->rpc_release(). Otherwise it won't
  clear the commit lock.

Cleanups:

- Let the files layout manage the commit lists for the pNFS case.
  Don't expose stuff like pnfs_choose_commit_list, and the fact
  that the commit buckets hold references to the layout segment
  in common code.

- Cast out the put_lseg() calls for the struct nfs_read/write_data->lseg
  into the pNFS layer from whence they came.

- Let the pNFS layer manage the NFS_INO_PNFS_COMMIT bit.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Cc: Fred Isaman <iisaman@netapp.com>

6 files changed, 172 insertions, 97 deletions

diff --git a/fs/nfs/internal.h b/fs/nfs/internal.h
index 04a914704e7b..2476dc69365f 100644
--- a/fs/nfs/internal.h
+++ b/fs/nfs/internal.h
@@ -308,8 +308,6 @@ extern void nfs_pageio_reset_read_mds(struct nfs_pageio_descriptor *pgio);
 extern void nfs_readdata_release(struct nfs_read_data *rdata);
 
 /* write.c */
-extern int nfs_scan_commit_list(struct list_head *src, struct list_head *dst,
-                                int max);
 extern int nfs_generic_flush(struct nfs_pageio_descriptor *desc,
                 struct list_head *head);
 extern void nfs_pageio_init_write_mds(struct nfs_pageio_descriptor *pgio,
@@ -334,6 +332,8 @@ void nfs_retry_commit(struct list_head *page_list,
 void nfs_commit_clear_lock(struct nfs_inode *nfsi);
 void nfs_commitdata_release(void *data);
 void nfs_commit_release_pages(struct nfs_write_data *data);
+void nfs_request_add_commit_list(struct nfs_page *req, struct list_head *head);
+void nfs_request_remove_commit_list(struct nfs_page *req);
 
 #ifdef CONFIG_MIGRATION
 extern int nfs_migrate_page(struct address_space *,
diff --git a/fs/nfs/nfs4filelayout.c b/fs/nfs/nfs4filelayout.c
index 379a085f8f25..c24e077c2820 100644
--- a/fs/nfs/nfs4filelayout.c
+++ b/fs/nfs/nfs4filelayout.c
@@ -224,6 +224,7 @@ static void filelayout_read_release(void *data)
 {
         struct nfs_read_data *rdata = (struct nfs_read_data *)data;
 
+        put_lseg(rdata->lseg);
         rdata->mds_ops->rpc_release(data);
 }
 
@@ -310,6 +311,7 @@ static void filelayout_write_release(void *data)
 {
         struct nfs_write_data *wdata = (struct nfs_write_data *)data;
 
+        put_lseg(wdata->lseg);
         wdata->mds_ops->rpc_release(data);
 }
 
@@ -320,6 +322,7 @@ static void filelayout_commit_release(void *data)
         nfs_commit_release_pages(wdata);
         if (atomic_dec_and_test(&NFS_I(wdata->inode)->commits_outstanding))
                 nfs_commit_clear_lock(NFS_I(wdata->inode));
+        put_lseg(wdata->lseg);
         nfs_commitdata_release(wdata);
 }
 
@@ -779,11 +782,16 @@ static u32 select_bucket_index(struct nfs4_filelayout_segment *fl, u32 j)
 
 /* The generic layer is about to remove the req from the commit list.
  * If this will make the bucket empty, it will need to put the lseg reference.
- * Note inode lock is held, so we can't do the put here.
  */
-static struct pnfs_layout_segment *
-filelayout_remove_commit_req(struct nfs_page *req)
+static void
+filelayout_clear_request_commit(struct nfs_page *req)
 {
+        struct pnfs_layout_segment *freeme = NULL;
+        struct inode *inode = req->wb_context->dentry->d_inode;
+
+        spin_lock(&inode->i_lock);
+        if (!test_and_clear_bit(PG_COMMIT_TO_DS, &req->wb_flags))
+                goto out;
         if (list_is_singular(&req->wb_list)) {
                 struct inode *inode = req->wb_context->dentry->d_inode;
                 struct pnfs_layout_segment *lseg;
@@ -792,11 +800,16 @@ filelayout_remove_commit_req(struct nfs_page *req)
                  * since there is only one relevant lseg...
                  */
                 list_for_each_entry(lseg, &NFS_I(inode)->layout->plh_segs, pls_list) {
-                        if (lseg->pls_range.iomode == IOMODE_RW)
-                                return lseg;
+                        if (lseg->pls_range.iomode == IOMODE_RW) {
+                                freeme = lseg;
+                                break;
+                        }
                 }
         }
-        return NULL;
+out:
+        nfs_request_remove_commit_list(req);
+        spin_unlock(&inode->i_lock);
+        put_lseg(freeme);
 }
 
 static struct list_head *
@@ -829,9 +842,20 @@ filelayout_choose_commit_list(struct nfs_page *req,
                  */
                 get_lseg(lseg);
         }
+        set_bit(PG_COMMIT_TO_DS, &req->wb_flags);
         return list;
 }
 
+static void
+filelayout_mark_request_commit(struct nfs_page *req,
+                struct pnfs_layout_segment *lseg)
+{
+        struct list_head *list;
+
+        list = filelayout_choose_commit_list(req, lseg);
+        nfs_request_add_commit_list(req, list);
+}
+
 static u32 calc_ds_index_from_commit(struct pnfs_layout_segment *lseg, u32 i)
 {
         struct nfs4_filelayout_segment *flseg = FILELAYOUT_LSEG(lseg);
@@ -872,7 +896,7 @@ static int filelayout_initiate_commit(struct nfs_write_data *data, int how)
                 set_bit(lo_fail_bit(IOMODE_RW), &lseg->pls_layout->plh_flags);
                 set_bit(lo_fail_bit(IOMODE_READ), &lseg->pls_layout->plh_flags);
                 prepare_to_resend_writes(data);
-                data->mds_ops->rpc_release(data);
+                filelayout_commit_release(data);
                 return -EAGAIN;
         }
         dprintk("%s ino %lu, how %d\n", __func__, data->inode->i_ino, how);
@@ -895,7 +919,7 @@ find_only_write_lseg_locked(struct inode *inode)
 
         list_for_each_entry(lseg, &NFS_I(inode)->layout->plh_segs, pls_list)
                 if (lseg->pls_range.iomode == IOMODE_RW)
-                        return get_lseg(lseg);
+                        return lseg;
         return NULL;
 }
 
@@ -905,10 +929,33 @@ static struct pnfs_layout_segment *find_only_write_lseg(struct inode *inode)
 
         spin_lock(&inode->i_lock);
         rv = find_only_write_lseg_locked(inode);
+        if (rv)
+                get_lseg(rv);
         spin_unlock(&inode->i_lock);
         return rv;
 }
 
+static int
+filelayout_scan_ds_commit_list(struct nfs4_fl_commit_bucket *bucket, int max)
+{
+        struct list_head *src = &bucket->written;
+        struct list_head *dst = &bucket->committing;
+        struct nfs_page *req, *tmp;
+        int ret = 0;
+
+        list_for_each_entry_safe(req, tmp, src, wb_list) {
+                if (!nfs_lock_request(req))
+                        continue;
+                nfs_request_remove_commit_list(req);
+                clear_bit(PG_COMMIT_TO_DS, &req->wb_flags);
+                nfs_list_add_request(req, dst);
+                ret++;
+                if (ret == max)
+                        break;
+        }
+        return ret;
+}
+
 /* Move reqs from written to committing lists, returning count of number moved.
  * Note called with i_lock held.
  */
@@ -920,21 +967,16 @@ static int filelayout_scan_commit_lists(struct inode *inode, int max)
 
         lseg = find_only_write_lseg_locked(inode);
         if (!lseg)
-                return 0;
+                goto out_done;
         fl = FILELAYOUT_LSEG(lseg);
         if (fl->commit_through_mds)
-                goto out_put;
-        for (i = 0; i < fl->number_of_buckets; i++) {
-                if (list_empty(&fl->commit_buckets[i].written))
-                        continue;
-                cnt = nfs_scan_commit_list(&fl->commit_buckets[i].written,
-                                           &fl->commit_buckets[i].committing,
-                                           max);
+                goto out_done;
+        for (i = 0; i < fl->number_of_buckets && max != 0; i++) {
+                cnt = filelayout_scan_ds_commit_list(&fl->commit_buckets[i], max);
                 max -= cnt;
                 rv += cnt;
         }
-out_put:
-        put_lseg(lseg);
+out_done:
         return rv;
 }
 
@@ -1033,8 +1075,8 @@ static struct pnfs_layoutdriver_type filelayout_type = {
         .free_lseg              = filelayout_free_lseg,
         .pg_read_ops            = &filelayout_pg_read_ops,
         .pg_write_ops           = &filelayout_pg_write_ops,
-        .choose_commit_list     = filelayout_choose_commit_list,
-        .remove_commit_req      = filelayout_remove_commit_req,
+        .mark_request_commit    = filelayout_mark_request_commit,
+        .clear_request_commit   = filelayout_clear_request_commit,
         .scan_commit_lists      = filelayout_scan_commit_lists,
         .commit_pagelist        = filelayout_commit_pagelist,
         .read_pagelist          = filelayout_read_pagelist,
diff --git a/fs/nfs/pnfs.c b/fs/nfs/pnfs.c
index 6f1c1e3d12bc..b5d451586943 100644
--- a/fs/nfs/pnfs.c
+++ b/fs/nfs/pnfs.c
@@ -1210,6 +1210,7 @@ void pnfs_ld_write_done(struct nfs_write_data *data)
                 }
                 data->task.tk_status = pnfs_write_done_resend_to_mds(data->inode, &data->pages);
         }
+        put_lseg(data->lseg);
         data->mds_ops->rpc_release(data);
 }
 EXPORT_SYMBOL_GPL(pnfs_ld_write_done);
@@ -1223,6 +1224,7 @@ pnfs_write_through_mds(struct nfs_pageio_descriptor *desc,
                 nfs_list_add_request(data->req, &desc->pg_list);
         nfs_pageio_reset_write_mds(desc);
         desc->pg_recoalesce = 1;
+        put_lseg(data->lseg);
         nfs_writedata_release(data);
 }
 
@@ -1323,6 +1325,7 @@ void pnfs_ld_read_done(struct nfs_read_data *data)
                 data->mds_ops->rpc_call_done(&data->task, data);
         } else
                 pnfs_ld_handle_read_error(data);
+        put_lseg(data->lseg);
         data->mds_ops->rpc_release(data);
 }
 EXPORT_SYMBOL_GPL(pnfs_ld_read_done);
diff --git a/fs/nfs/pnfs.h b/fs/nfs/pnfs.h
index ef92f676cf1e..e98ff3027d3a 100644
--- a/fs/nfs/pnfs.h
+++ b/fs/nfs/pnfs.h
@@ -94,9 +94,9 @@ struct pnfs_layoutdriver_type {
         const struct nfs_pageio_ops *pg_read_ops;
         const struct nfs_pageio_ops *pg_write_ops;
 
-        struct list_head * (*choose_commit_list) (struct nfs_page *req,
+        void (*mark_request_commit) (struct nfs_page *req,
                                         struct pnfs_layout_segment *lseg);
-        struct pnfs_layout_segment *(*remove_commit_req) (struct nfs_page *req);
+        void (*clear_request_commit) (struct nfs_page *req);
         int (*scan_commit_lists) (struct inode *inode, int max);
         int (*commit_pagelist)(struct inode *inode, struct list_head *mds_pages, int how);
 
@@ -269,39 +269,42 @@ pnfs_commit_list(struct inode *inode, struct list_head *mds_pages, int how)
         return NFS_SERVER(inode)->pnfs_curr_ld->commit_pagelist(inode, mds_pages, how);
 }
 
-static inline struct list_head *
-pnfs_choose_commit_list(struct nfs_page *req, struct pnfs_layout_segment *lseg)
+static inline bool
+pnfs_mark_request_commit(struct nfs_page *req, struct pnfs_layout_segment *lseg)
 {
         struct inode *inode = req->wb_context->dentry->d_inode;
-        struct list_head *rv;
+        struct pnfs_layoutdriver_type *ld = NFS_SERVER(inode)->pnfs_curr_ld;
 
-        if (lseg && NFS_SERVER(inode)->pnfs_curr_ld->choose_commit_list)
-                rv = NFS_SERVER(inode)->pnfs_curr_ld->choose_commit_list(req, lseg);
-        else
-                rv = &NFS_I(inode)->commit_list;
-        return rv;
+        if (lseg == NULL || ld->mark_request_commit == NULL)
+                return false;
+        ld->mark_request_commit(req, lseg);
+        return true;
 }
 
-static inline struct pnfs_layout_segment *
+static inline bool
 pnfs_clear_request_commit(struct nfs_page *req)
 {
         struct inode *inode = req->wb_context->dentry->d_inode;
+        struct pnfs_layoutdriver_type *ld = NFS_SERVER(inode)->pnfs_curr_ld;
 
-        if (NFS_SERVER(inode)->pnfs_curr_ld &&
-            NFS_SERVER(inode)->pnfs_curr_ld->remove_commit_req)
-                return NFS_SERVER(inode)->pnfs_curr_ld->remove_commit_req(req);
-        else
-                return NULL;
+        if (ld == NULL || ld->clear_request_commit == NULL)
+                return false;
+        ld->clear_request_commit(req);
+        return true;
 }
 
 static inline int
 pnfs_scan_commit_lists(struct inode *inode, int max)
 {
-        if (NFS_SERVER(inode)->pnfs_curr_ld &&
-            NFS_SERVER(inode)->pnfs_curr_ld->scan_commit_lists)
-                return NFS_SERVER(inode)->pnfs_curr_ld->scan_commit_lists(inode, max);
-        else
+        struct pnfs_layoutdriver_type *ld = NFS_SERVER(inode)->pnfs_curr_ld;
+        int ret;
+
+        if (ld == NULL || ld->scan_commit_lists == NULL)
                 return 0;
+        ret = ld->scan_commit_lists(inode, max);
+        if (ret != 0)
+                set_bit(NFS_INO_PNFS_COMMIT, &NFS_I(inode)->flags);
+        return ret;
 }
 
 /* Should the pNFS client commit and return the layout upon a setattr */
@@ -403,18 +406,16 @@ pnfs_commit_list(struct inode *inode, struct list_head *mds_pages, int how)
         return PNFS_NOT_ATTEMPTED;
 }
 
-static inline struct list_head *
-pnfs_choose_commit_list(struct nfs_page *req, struct pnfs_layout_segment *lseg)
+static inline bool
+pnfs_mark_request_commit(struct nfs_page *req, struct pnfs_layout_segment *lseg)
 {
-        struct inode *inode = req->wb_context->dentry->d_inode;
-
-        return &NFS_I(inode)->commit_list;
+        return false;
 }
 
-static inline struct pnfs_layout_segment *
+static inline bool
 pnfs_clear_request_commit(struct nfs_page *req)
 {
-        return NULL;
+        return false;
 }
 
 static inline int
diff --git a/fs/nfs/read.c b/fs/nfs/read.c
index 3c2540d532c7..2662c0298dd0 100644
--- a/fs/nfs/read.c
+++ b/fs/nfs/read.c
@@ -66,7 +66,6 @@ void nfs_readdata_free(struct nfs_read_data *p)
 
 void nfs_readdata_release(struct nfs_read_data *rdata)
 {
-        put_lseg(rdata->lseg);
         put_nfs_open_context(rdata->args.context);
         nfs_readdata_free(rdata);
 }
diff --git a/fs/nfs/write.c b/fs/nfs/write.c
index a630ad65d64c..0de19f413f92 100644
--- a/fs/nfs/write.c
+++ b/fs/nfs/write.c
@@ -100,7 +100,6 @@ void nfs_writedata_free(struct nfs_write_data *p)
 
 void nfs_writedata_release(struct nfs_write_data *wdata)
 {
-        put_lseg(wdata->lseg);
         put_nfs_open_context(wdata->args.context);
         nfs_writedata_free(wdata);
 }
@@ -393,8 +392,6 @@ static void nfs_inode_add_request(struct inode *inode, struct nfs_page *req)
         spin_unlock(&inode->i_lock);
 }
 
-static struct pnfs_layout_segment *nfs_clear_request_commit(struct nfs_page *req);
-
 /*
  * Remove a write request from an inode
  */
@@ -402,18 +399,15 @@ static void nfs_inode_remove_request(struct nfs_page *req)
 {
         struct inode *inode = req->wb_context->dentry->d_inode;
         struct nfs_inode *nfsi = NFS_I(inode);
-        struct pnfs_layout_segment *lseg;
 
         BUG_ON (!NFS_WBACK_BUSY(req));
 
         spin_lock(&inode->i_lock);
-        lseg = nfs_clear_request_commit(req);
         set_page_private(req->wb_page, 0);
         ClearPagePrivate(req->wb_page);
         clear_bit(PG_MAPPED, &req->wb_flags);
         nfsi->npages--;
         spin_unlock(&inode->i_lock);
-        put_lseg(lseg);
         nfs_release_request(req);
 }
 
@@ -424,26 +418,69 @@ nfs_mark_request_dirty(struct nfs_page *req)
 }
 
 #if defined(CONFIG_NFS_V3) || defined(CONFIG_NFS_V4)
-/*
- * Add a request to the inode's commit list.
+/**
+ * nfs_request_add_commit_list - add request to a commit list
+ * @req: pointer to a struct nfs_page
+ * @head: commit list head
+ *
+ * This sets the PG_CLEAN bit, updates the inode global count of
+ * number of outstanding requests requiring a commit as well as
+ * the MM page stats.
+ *
+ * The caller must _not_ hold the inode->i_lock, but must be
+ * holding the nfs_page lock.
  */
-static void
-nfs_mark_request_commit(struct nfs_page *req, struct pnfs_layout_segment *lseg)
+void
+nfs_request_add_commit_list(struct nfs_page *req, struct list_head *head)
 {
         struct inode *inode = req->wb_context->dentry->d_inode;
-        struct nfs_inode *nfsi = NFS_I(inode);
-        struct list_head *clist;
 
-        clist = pnfs_choose_commit_list(req, lseg);
-        spin_lock(&inode->i_lock);
         set_bit(PG_CLEAN, &(req)->wb_flags);
-        nfs_list_add_request(req, clist);
-        nfsi->ncommit++;
+        spin_lock(&inode->i_lock);
+        nfs_list_add_request(req, head);
+        NFS_I(inode)->ncommit++;
         spin_unlock(&inode->i_lock);
         inc_zone_page_state(req->wb_page, NR_UNSTABLE_NFS);
         inc_bdi_stat(req->wb_page->mapping->backing_dev_info, BDI_RECLAIMABLE);
         __mark_inode_dirty(inode, I_DIRTY_DATASYNC);
 }
+EXPORT_SYMBOL_GPL(nfs_request_add_commit_list);
+
+/**
+ * nfs_request_remove_commit_list - Remove request from a commit list
+ * @req: pointer to a nfs_page
+ *
+ * This clears the PG_CLEAN bit, and updates the inode global count of
+ * number of outstanding requests requiring a commit
+ * It does not update the MM page stats.
+ *
+ * The caller _must_ hold the inode->i_lock and the nfs_page lock.
+ */
+void
+nfs_request_remove_commit_list(struct nfs_page *req)
+{
+        struct inode *inode = req->wb_context->dentry->d_inode;
+
+        if (!test_and_clear_bit(PG_CLEAN, &(req)->wb_flags))
+                return;
+        nfs_list_remove_request(req);
+        NFS_I(inode)->ncommit--;
+}
+EXPORT_SYMBOL_GPL(nfs_request_remove_commit_list);
+
+
+/*
+ * Add a request to the inode's commit list.
+ */
+static void
+nfs_mark_request_commit(struct nfs_page *req, struct pnfs_layout_segment *lseg)
+{
+        struct inode *inode = req->wb_context->dentry->d_inode;
+
+        if (pnfs_mark_request_commit(req, lseg))
+                return;
+        nfs_request_add_commit_list(req, &NFS_I(inode)->commit_list);
+}
 
 static void
 nfs_clear_page_commit(struct page *page)
@@ -452,18 +489,19 @@ nfs_clear_page_commit(struct page *page)
         dec_bdi_stat(page->mapping->backing_dev_info, BDI_RECLAIMABLE);
 }
 
-static struct pnfs_layout_segment *
+static void
 nfs_clear_request_commit(struct nfs_page *req)
 {
-        struct pnfs_layout_segment *lseg = NULL;
+        if (test_bit(PG_CLEAN, &req->wb_flags)) {
+                struct inode *inode = req->wb_context->dentry->d_inode;
 
-        if (test_and_clear_bit(PG_CLEAN, &(req)->wb_flags)) {
+                if (!pnfs_clear_request_commit(req)) {
+                        spin_lock(&inode->i_lock);
+                        nfs_request_remove_commit_list(req);
+                        spin_unlock(&inode->i_lock);
+                }
                 nfs_clear_page_commit(req->wb_page);
-                lseg = pnfs_clear_request_commit(req);
-                NFS_I(req->wb_context->dentry->d_inode)->ncommit--;
-                list_del(&req->wb_list);
         }
-        return lseg;
 }
 
 static inline
@@ -490,15 +528,14 @@ int nfs_reschedule_unstable_write(struct nfs_page *req,
         return 0;
 }
 #else
-static inline void
+static void
 nfs_mark_request_commit(struct nfs_page *req, struct pnfs_layout_segment *lseg)
 {
 }
 
-static inline struct pnfs_layout_segment *
+static void
 nfs_clear_request_commit(struct nfs_page *req)
 {
-        return NULL;
 }
 
 static inline
@@ -523,25 +560,23 @@ nfs_need_commit(struct nfs_inode *nfsi)
 }
 
 /* i_lock held by caller */
-int
+static int
 nfs_scan_commit_list(struct list_head *src, struct list_head *dst, int max)
 {
         struct nfs_page *req, *tmp;
         int ret = 0;
 
         list_for_each_entry_safe(req, tmp, src, wb_list) {
-                if (nfs_lock_request_dontget(req)) {
-                        kref_get(&req->wb_kref);
-                        list_move_tail(&req->wb_list, dst);
-                        clear_bit(PG_CLEAN, &(req)->wb_flags);
-                        ret++;
-                        if (ret == max)
-                                break;
-                }
+                if (!nfs_lock_request(req))
+                        continue;
+                nfs_request_remove_commit_list(req);
+                nfs_list_add_request(req, dst);
+                ret++;
+                if (ret == max)
+                        break;
         }
         return ret;
 }
-EXPORT_SYMBOL_GPL(nfs_scan_commit_list);
 
 /*
  * nfs_scan_commit - Scan an inode for commit requests
@@ -559,14 +594,12 @@ nfs_scan_commit(struct inode *inode, struct list_head *dst)
 
         spin_lock(&inode->i_lock);
         if (nfsi->ncommit > 0) {
+                const int max = INT_MAX;
                 int pnfs_ret;
 
-                ret = nfs_scan_commit_list(&nfsi->commit_list, dst, INT_MAX);
-                pnfs_ret = pnfs_scan_commit_lists(inode, INT_MAX - ret);
-                if (pnfs_ret) {
-                        ret += pnfs_ret;
-                        set_bit(NFS_INO_PNFS_COMMIT, &nfsi->flags);
-                }
+                ret = nfs_scan_commit_list(&nfsi->commit_list, dst, max);
+                pnfs_ret = pnfs_scan_commit_lists(inode, max - ret);
+                ret += pnfs_ret;
                 nfsi->ncommit -= ret;
         }
         spin_unlock(&inode->i_lock);
@@ -601,7 +634,6 @@ static struct nfs_page *nfs_try_to_update_request(struct inode *inode,
         unsigned int rqend;
         unsigned int end;
         int error;
-        struct pnfs_layout_segment *lseg = NULL;
 
         if (!PagePrivate(page))
                 return NULL;
@@ -637,8 +669,6 @@ static struct nfs_page *nfs_try_to_update_request(struct inode *inode,
                 spin_lock(&inode->i_lock);
         }
 
-        lseg = nfs_clear_request_commit(req);
-
         /* Okay, the request matches. Update the region */
         if (offset < req->wb_offset) {
                 req->wb_offset = offset;
@@ -650,7 +680,7 @@ static struct nfs_page *nfs_try_to_update_request(struct inode *inode,
                 req->wb_bytes = rqend - req->wb_offset;
 out_unlock:
         spin_unlock(&inode->i_lock);
-        put_lseg(lseg);
+        nfs_clear_request_commit(req);
         return req;
 out_flushme:
         spin_unlock(&inode->i_lock);
@@ -1337,7 +1367,6 @@ void nfs_commitdata_release(void *data)
 {
         struct nfs_write_data *wdata = data;
 
-        put_lseg(wdata->lseg);
         put_nfs_open_context(wdata->args.context);
         nfs_commit_free(wdata);
 }
@@ -1647,6 +1676,7 @@ int nfs_wb_page_cancel(struct inode *inode, struct page *page)
                 if (req == NULL)
                         break;
                 if (nfs_lock_request_dontget(req)) {
+                        nfs_clear_request_commit(req);
                         nfs_inode_remove_request(req);
                         /*
                          * In case nfs_inode_remove_request has marked the