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authorLinus Torvalds <torvalds@linux-foundation.org>2014-06-11 02:02:42 +0400
committerLinus Torvalds <torvalds@linux-foundation.org>2014-06-11 02:02:42 +0400
commitd1e1cda862c16252087374ac75949b0e89a5717e (patch)
tree544ce467bed23638949a1991b4f7b00e7472baa4 /fs/nfs/pagelist.c
parent07888238f55056605cd23aa4ea3ca97d5e15938f (diff)
parenta914722f333b3359d2f4f12919380a334176bb89 (diff)
downloadlinux-d1e1cda862c16252087374ac75949b0e89a5717e.tar.xz
Merge tag 'nfs-for-3.16-1' of git://git.linux-nfs.org/projects/trondmy/linux-nfs
Pull NFS client updates from Trond Myklebust: "Highlights include: - massive cleanup of the NFS read/write code by Anna and Dros - support multiple NFS read/write requests per page in order to deal with non-page aligned pNFS striping. Also cleans up the r/wsize < page size code nicely. - stable fix for ensuring inode is declared uptodate only after all the attributes have been checked. - stable fix for a kernel Oops when remounting - NFS over RDMA client fixes - move the pNFS files layout driver into its own subdirectory" * tag 'nfs-for-3.16-1' of git://git.linux-nfs.org/projects/trondmy/linux-nfs: (79 commits) NFS: populate ->net in mount data when remounting pnfs: fix lockup caused by pnfs_generic_pg_test NFSv4.1: Fix typo in dprintk NFSv4.1: Comment is now wrong and redundant to code NFS: Use raw_write_seqcount_begin/end int nfs4_reclaim_open_state xprtrdma: Disconnect on registration failure xprtrdma: Remove BUG_ON() call sites xprtrdma: Avoid deadlock when credit window is reset SUNRPC: Move congestion window constants to header file xprtrdma: Reset connection timeout after successful reconnect xprtrdma: Use macros for reconnection timeout constants xprtrdma: Allocate missing pagelist xprtrdma: Remove Tavor MTU setting xprtrdma: Ensure ia->ri_id->qp is not NULL when reconnecting xprtrdma: Reduce the number of hardway buffer allocations xprtrdma: Limit work done by completion handler xprtrmda: Reduce calls to ib_poll_cq() in completion handlers xprtrmda: Reduce lock contention in completion handlers xprtrdma: Split the completion queue xprtrdma: Make rpcrdma_ep_destroy() return void ...
Diffstat (limited to 'fs/nfs/pagelist.c')
-rw-r--r--fs/nfs/pagelist.c633
1 files changed, 583 insertions, 50 deletions
diff --git a/fs/nfs/pagelist.c b/fs/nfs/pagelist.c
index 03ed984ab4d8..b6ee3a6ee96d 100644
--- a/fs/nfs/pagelist.c
+++ b/fs/nfs/pagelist.c
@@ -24,9 +24,14 @@
#include "internal.h"
#include "pnfs.h"
+#define NFSDBG_FACILITY NFSDBG_PAGECACHE
+
static struct kmem_cache *nfs_page_cachep;
+static const struct rpc_call_ops nfs_pgio_common_ops;
+
+static void nfs_free_request(struct nfs_page *);
-bool nfs_pgarray_set(struct nfs_page_array *p, unsigned int pagecount)
+static bool nfs_pgarray_set(struct nfs_page_array *p, unsigned int pagecount)
{
p->npages = pagecount;
if (pagecount <= ARRAY_SIZE(p->page_array))
@@ -133,11 +138,156 @@ nfs_iocounter_wait(struct nfs_io_counter *c)
return __nfs_iocounter_wait(c);
}
+static int nfs_wait_bit_uninterruptible(void *word)
+{
+ io_schedule();
+ return 0;
+}
+
+/*
+ * nfs_page_group_lock - lock the head of the page group
+ * @req - request in group that is to be locked
+ *
+ * this lock must be held if modifying the page group list
+ */
+void
+nfs_page_group_lock(struct nfs_page *req)
+{
+ struct nfs_page *head = req->wb_head;
+
+ WARN_ON_ONCE(head != head->wb_head);
+
+ wait_on_bit_lock(&head->wb_flags, PG_HEADLOCK,
+ nfs_wait_bit_uninterruptible,
+ TASK_UNINTERRUPTIBLE);
+}
+
+/*
+ * nfs_page_group_unlock - unlock the head of the page group
+ * @req - request in group that is to be unlocked
+ */
+void
+nfs_page_group_unlock(struct nfs_page *req)
+{
+ struct nfs_page *head = req->wb_head;
+
+ WARN_ON_ONCE(head != head->wb_head);
+
+ smp_mb__before_atomic();
+ clear_bit(PG_HEADLOCK, &head->wb_flags);
+ smp_mb__after_atomic();
+ wake_up_bit(&head->wb_flags, PG_HEADLOCK);
+}
+
+/*
+ * nfs_page_group_sync_on_bit_locked
+ *
+ * must be called with page group lock held
+ */
+static bool
+nfs_page_group_sync_on_bit_locked(struct nfs_page *req, unsigned int bit)
+{
+ struct nfs_page *head = req->wb_head;
+ struct nfs_page *tmp;
+
+ WARN_ON_ONCE(!test_bit(PG_HEADLOCK, &head->wb_flags));
+ WARN_ON_ONCE(test_and_set_bit(bit, &req->wb_flags));
+
+ tmp = req->wb_this_page;
+ while (tmp != req) {
+ if (!test_bit(bit, &tmp->wb_flags))
+ return false;
+ tmp = tmp->wb_this_page;
+ }
+
+ /* true! reset all bits */
+ tmp = req;
+ do {
+ clear_bit(bit, &tmp->wb_flags);
+ tmp = tmp->wb_this_page;
+ } while (tmp != req);
+
+ return true;
+}
+
+/*
+ * nfs_page_group_sync_on_bit - set bit on current request, but only
+ * return true if the bit is set for all requests in page group
+ * @req - request in page group
+ * @bit - PG_* bit that is used to sync page group
+ */
+bool nfs_page_group_sync_on_bit(struct nfs_page *req, unsigned int bit)
+{
+ bool ret;
+
+ nfs_page_group_lock(req);
+ ret = nfs_page_group_sync_on_bit_locked(req, bit);
+ nfs_page_group_unlock(req);
+
+ return ret;
+}
+
+/*
+ * nfs_page_group_init - Initialize the page group linkage for @req
+ * @req - a new nfs request
+ * @prev - the previous request in page group, or NULL if @req is the first
+ * or only request in the group (the head).
+ */
+static inline void
+nfs_page_group_init(struct nfs_page *req, struct nfs_page *prev)
+{
+ WARN_ON_ONCE(prev == req);
+
+ if (!prev) {
+ req->wb_head = req;
+ req->wb_this_page = req;
+ } else {
+ WARN_ON_ONCE(prev->wb_this_page != prev->wb_head);
+ WARN_ON_ONCE(!test_bit(PG_HEADLOCK, &prev->wb_head->wb_flags));
+ req->wb_head = prev->wb_head;
+ req->wb_this_page = prev->wb_this_page;
+ prev->wb_this_page = req;
+
+ /* grab extra ref if head request has extra ref from
+ * the write/commit path to handle handoff between write
+ * and commit lists */
+ if (test_bit(PG_INODE_REF, &prev->wb_head->wb_flags))
+ kref_get(&req->wb_kref);
+ }
+}
+
+/*
+ * nfs_page_group_destroy - sync the destruction of page groups
+ * @req - request that no longer needs the page group
+ *
+ * releases the page group reference from each member once all
+ * members have called this function.
+ */
+static void
+nfs_page_group_destroy(struct kref *kref)
+{
+ struct nfs_page *req = container_of(kref, struct nfs_page, wb_kref);
+ struct nfs_page *tmp, *next;
+
+ if (!nfs_page_group_sync_on_bit(req, PG_TEARDOWN))
+ return;
+
+ tmp = req;
+ do {
+ next = tmp->wb_this_page;
+ /* unlink and free */
+ tmp->wb_this_page = tmp;
+ tmp->wb_head = tmp;
+ nfs_free_request(tmp);
+ tmp = next;
+ } while (tmp != req);
+}
+
/**
* nfs_create_request - Create an NFS read/write request.
* @ctx: open context to use
- * @inode: inode to which the request is attached
* @page: page to write
+ * @last: last nfs request created for this page group or NULL if head
* @offset: starting offset within the page for the write
* @count: number of bytes to read/write
*
@@ -146,9 +296,9 @@ nfs_iocounter_wait(struct nfs_io_counter *c)
* User should ensure it is safe to sleep in this function.
*/
struct nfs_page *
-nfs_create_request(struct nfs_open_context *ctx, struct inode *inode,
- struct page *page,
- unsigned int offset, unsigned int count)
+nfs_create_request(struct nfs_open_context *ctx, struct page *page,
+ struct nfs_page *last, unsigned int offset,
+ unsigned int count)
{
struct nfs_page *req;
struct nfs_lock_context *l_ctx;
@@ -180,6 +330,7 @@ nfs_create_request(struct nfs_open_context *ctx, struct inode *inode,
req->wb_bytes = count;
req->wb_context = get_nfs_open_context(ctx);
kref_init(&req->wb_kref);
+ nfs_page_group_init(req, last);
return req;
}
@@ -237,16 +388,22 @@ static void nfs_clear_request(struct nfs_page *req)
}
}
-
/**
* nfs_release_request - Release the count on an NFS read/write request
* @req: request to release
*
* Note: Should never be called with the spinlock held!
*/
-static void nfs_free_request(struct kref *kref)
+static void nfs_free_request(struct nfs_page *req)
{
- struct nfs_page *req = container_of(kref, struct nfs_page, wb_kref);
+ WARN_ON_ONCE(req->wb_this_page != req);
+
+ /* extra debug: make sure no sync bits are still set */
+ WARN_ON_ONCE(test_bit(PG_TEARDOWN, &req->wb_flags));
+ WARN_ON_ONCE(test_bit(PG_UNLOCKPAGE, &req->wb_flags));
+ WARN_ON_ONCE(test_bit(PG_UPTODATE, &req->wb_flags));
+ WARN_ON_ONCE(test_bit(PG_WB_END, &req->wb_flags));
+ WARN_ON_ONCE(test_bit(PG_REMOVE, &req->wb_flags));
/* Release struct file and open context */
nfs_clear_request(req);
@@ -255,13 +412,7 @@ static void nfs_free_request(struct kref *kref)
void nfs_release_request(struct nfs_page *req)
{
- kref_put(&req->wb_kref, nfs_free_request);
-}
-
-static int nfs_wait_bit_uninterruptible(void *word)
-{
- io_schedule();
- return 0;
+ kref_put(&req->wb_kref, nfs_page_group_destroy);
}
/**
@@ -279,22 +430,249 @@ nfs_wait_on_request(struct nfs_page *req)
TASK_UNINTERRUPTIBLE);
}
-bool nfs_generic_pg_test(struct nfs_pageio_descriptor *desc, struct nfs_page *prev, struct nfs_page *req)
+/*
+ * nfs_generic_pg_test - determine if requests can be coalesced
+ * @desc: pointer to descriptor
+ * @prev: previous request in desc, or NULL
+ * @req: this request
+ *
+ * Returns zero if @req can be coalesced into @desc, otherwise it returns
+ * the size of the request.
+ */
+size_t nfs_generic_pg_test(struct nfs_pageio_descriptor *desc,
+ struct nfs_page *prev, struct nfs_page *req)
{
- /*
- * FIXME: ideally we should be able to coalesce all requests
- * that are not block boundary aligned, but currently this
- * is problematic for the case of bsize < PAGE_CACHE_SIZE,
- * since nfs_flush_multi and nfs_pagein_multi assume you
- * can have only one struct nfs_page.
- */
- if (desc->pg_bsize < PAGE_SIZE)
+ if (desc->pg_count > desc->pg_bsize) {
+ /* should never happen */
+ WARN_ON_ONCE(1);
return 0;
+ }
- return desc->pg_count + req->wb_bytes <= desc->pg_bsize;
+ return min(desc->pg_bsize - desc->pg_count, (size_t)req->wb_bytes);
}
EXPORT_SYMBOL_GPL(nfs_generic_pg_test);
+static inline struct nfs_rw_header *NFS_RW_HEADER(struct nfs_pgio_header *hdr)
+{
+ return container_of(hdr, struct nfs_rw_header, header);
+}
+
+/**
+ * nfs_rw_header_alloc - Allocate a header for a read or write
+ * @ops: Read or write function vector
+ */
+struct nfs_rw_header *nfs_rw_header_alloc(const struct nfs_rw_ops *ops)
+{
+ struct nfs_rw_header *header = ops->rw_alloc_header();
+
+ if (header) {
+ struct nfs_pgio_header *hdr = &header->header;
+
+ INIT_LIST_HEAD(&hdr->pages);
+ spin_lock_init(&hdr->lock);
+ atomic_set(&hdr->refcnt, 0);
+ hdr->rw_ops = ops;
+ }
+ return header;
+}
+EXPORT_SYMBOL_GPL(nfs_rw_header_alloc);
+
+/*
+ * nfs_rw_header_free - Free a read or write header
+ * @hdr: The header to free
+ */
+void nfs_rw_header_free(struct nfs_pgio_header *hdr)
+{
+ hdr->rw_ops->rw_free_header(NFS_RW_HEADER(hdr));
+}
+EXPORT_SYMBOL_GPL(nfs_rw_header_free);
+
+/**
+ * nfs_pgio_data_alloc - Allocate pageio data
+ * @hdr: The header making a request
+ * @pagecount: Number of pages to create
+ */
+static struct nfs_pgio_data *nfs_pgio_data_alloc(struct nfs_pgio_header *hdr,
+ unsigned int pagecount)
+{
+ struct nfs_pgio_data *data, *prealloc;
+
+ prealloc = &NFS_RW_HEADER(hdr)->rpc_data;
+ if (prealloc->header == NULL)
+ data = prealloc;
+ else
+ data = kzalloc(sizeof(*data), GFP_KERNEL);
+ if (!data)
+ goto out;
+
+ if (nfs_pgarray_set(&data->pages, pagecount)) {
+ data->header = hdr;
+ atomic_inc(&hdr->refcnt);
+ } else {
+ if (data != prealloc)
+ kfree(data);
+ data = NULL;
+ }
+out:
+ return data;
+}
+
+/**
+ * nfs_pgio_data_release - Properly free pageio data
+ * @data: The data to release
+ */
+void nfs_pgio_data_release(struct nfs_pgio_data *data)
+{
+ struct nfs_pgio_header *hdr = data->header;
+ struct nfs_rw_header *pageio_header = NFS_RW_HEADER(hdr);
+
+ put_nfs_open_context(data->args.context);
+ if (data->pages.pagevec != data->pages.page_array)
+ kfree(data->pages.pagevec);
+ if (data == &pageio_header->rpc_data) {
+ data->header = NULL;
+ data = NULL;
+ }
+ if (atomic_dec_and_test(&hdr->refcnt))
+ hdr->completion_ops->completion(hdr);
+ /* Note: we only free the rpc_task after callbacks are done.
+ * See the comment in rpc_free_task() for why
+ */
+ kfree(data);
+}
+EXPORT_SYMBOL_GPL(nfs_pgio_data_release);
+
+/**
+ * nfs_pgio_rpcsetup - Set up arguments for a pageio call
+ * @data: The pageio data
+ * @count: Number of bytes to read
+ * @offset: Initial offset
+ * @how: How to commit data (writes only)
+ * @cinfo: Commit information for the call (writes only)
+ */
+static void nfs_pgio_rpcsetup(struct nfs_pgio_data *data,
+ unsigned int count, unsigned int offset,
+ int how, struct nfs_commit_info *cinfo)
+{
+ struct nfs_page *req = data->header->req;
+
+ /* Set up the RPC argument and reply structs
+ * NB: take care not to mess about with data->commit et al. */
+
+ data->args.fh = NFS_FH(data->header->inode);
+ data->args.offset = req_offset(req) + offset;
+ /* pnfs_set_layoutcommit needs this */
+ data->mds_offset = data->args.offset;
+ data->args.pgbase = req->wb_pgbase + offset;
+ data->args.pages = data->pages.pagevec;
+ data->args.count = count;
+ data->args.context = get_nfs_open_context(req->wb_context);
+ data->args.lock_context = req->wb_lock_context;
+ data->args.stable = NFS_UNSTABLE;
+ switch (how & (FLUSH_STABLE | FLUSH_COND_STABLE)) {
+ case 0:
+ break;
+ case FLUSH_COND_STABLE:
+ if (nfs_reqs_to_commit(cinfo))
+ break;
+ default:
+ data->args.stable = NFS_FILE_SYNC;
+ }
+
+ data->res.fattr = &data->fattr;
+ data->res.count = count;
+ data->res.eof = 0;
+ data->res.verf = &data->verf;
+ nfs_fattr_init(&data->fattr);
+}
+
+/**
+ * nfs_pgio_prepare - Prepare pageio data to go over the wire
+ * @task: The current task
+ * @calldata: pageio data to prepare
+ */
+static void nfs_pgio_prepare(struct rpc_task *task, void *calldata)
+{
+ struct nfs_pgio_data *data = calldata;
+ int err;
+ err = NFS_PROTO(data->header->inode)->pgio_rpc_prepare(task, data);
+ if (err)
+ rpc_exit(task, err);
+}
+
+int nfs_initiate_pgio(struct rpc_clnt *clnt, struct nfs_pgio_data *data,
+ const struct rpc_call_ops *call_ops, int how, int flags)
+{
+ struct rpc_task *task;
+ struct rpc_message msg = {
+ .rpc_argp = &data->args,
+ .rpc_resp = &data->res,
+ .rpc_cred = data->header->cred,
+ };
+ struct rpc_task_setup task_setup_data = {
+ .rpc_client = clnt,
+ .task = &data->task,
+ .rpc_message = &msg,
+ .callback_ops = call_ops,
+ .callback_data = data,
+ .workqueue = nfsiod_workqueue,
+ .flags = RPC_TASK_ASYNC | flags,
+ };
+ int ret = 0;
+
+ data->header->rw_ops->rw_initiate(data, &msg, &task_setup_data, how);
+
+ dprintk("NFS: %5u initiated pgio call "
+ "(req %s/%llu, %u bytes @ offset %llu)\n",
+ data->task.tk_pid,
+ data->header->inode->i_sb->s_id,
+ (unsigned long long)NFS_FILEID(data->header->inode),
+ data->args.count,
+ (unsigned long long)data->args.offset);
+
+ task = rpc_run_task(&task_setup_data);
+ if (IS_ERR(task)) {
+ ret = PTR_ERR(task);
+ goto out;
+ }
+ if (how & FLUSH_SYNC) {
+ ret = rpc_wait_for_completion_task(task);
+ if (ret == 0)
+ ret = task->tk_status;
+ }
+ rpc_put_task(task);
+out:
+ return ret;
+}
+EXPORT_SYMBOL_GPL(nfs_initiate_pgio);
+
+/**
+ * nfs_pgio_error - Clean up from a pageio error
+ * @desc: IO descriptor
+ * @hdr: pageio header
+ */
+static int nfs_pgio_error(struct nfs_pageio_descriptor *desc,
+ struct nfs_pgio_header *hdr)
+{
+ set_bit(NFS_IOHDR_REDO, &hdr->flags);
+ nfs_pgio_data_release(hdr->data);
+ hdr->data = NULL;
+ desc->pg_completion_ops->error_cleanup(&desc->pg_list);
+ return -ENOMEM;
+}
+
+/**
+ * nfs_pgio_release - Release pageio data
+ * @calldata: The pageio data to release
+ */
+static void nfs_pgio_release(void *calldata)
+{
+ struct nfs_pgio_data *data = calldata;
+ if (data->header->rw_ops->rw_release)
+ data->header->rw_ops->rw_release(data);
+ nfs_pgio_data_release(data);
+}
+
/**
* nfs_pageio_init - initialise a page io descriptor
* @desc: pointer to descriptor
@@ -307,6 +685,7 @@ void nfs_pageio_init(struct nfs_pageio_descriptor *desc,
struct inode *inode,
const struct nfs_pageio_ops *pg_ops,
const struct nfs_pgio_completion_ops *compl_ops,
+ const struct nfs_rw_ops *rw_ops,
size_t bsize,
int io_flags)
{
@@ -320,6 +699,7 @@ void nfs_pageio_init(struct nfs_pageio_descriptor *desc,
desc->pg_inode = inode;
desc->pg_ops = pg_ops;
desc->pg_completion_ops = compl_ops;
+ desc->pg_rw_ops = rw_ops;
desc->pg_ioflags = io_flags;
desc->pg_error = 0;
desc->pg_lseg = NULL;
@@ -328,6 +708,94 @@ void nfs_pageio_init(struct nfs_pageio_descriptor *desc,
}
EXPORT_SYMBOL_GPL(nfs_pageio_init);
+/**
+ * nfs_pgio_result - Basic pageio error handling
+ * @task: The task that ran
+ * @calldata: Pageio data to check
+ */
+static void nfs_pgio_result(struct rpc_task *task, void *calldata)
+{
+ struct nfs_pgio_data *data = calldata;
+ struct inode *inode = data->header->inode;
+
+ dprintk("NFS: %s: %5u, (status %d)\n", __func__,
+ task->tk_pid, task->tk_status);
+
+ if (data->header->rw_ops->rw_done(task, data, inode) != 0)
+ return;
+ if (task->tk_status < 0)
+ nfs_set_pgio_error(data->header, task->tk_status, data->args.offset);
+ else
+ data->header->rw_ops->rw_result(task, data);
+}
+
+/*
+ * Create an RPC task for the given read or write request and kick it.
+ * The page must have been locked by the caller.
+ *
+ * It may happen that the page we're passed is not marked dirty.
+ * This is the case if nfs_updatepage detects a conflicting request
+ * that has been written but not committed.
+ */
+int nfs_generic_pgio(struct nfs_pageio_descriptor *desc,
+ struct nfs_pgio_header *hdr)
+{
+ struct nfs_page *req;
+ struct page **pages;
+ struct nfs_pgio_data *data;
+ struct list_head *head = &desc->pg_list;
+ struct nfs_commit_info cinfo;
+
+ data = nfs_pgio_data_alloc(hdr, nfs_page_array_len(desc->pg_base,
+ desc->pg_count));
+ if (!data)
+ return nfs_pgio_error(desc, hdr);
+
+ nfs_init_cinfo(&cinfo, desc->pg_inode, desc->pg_dreq);
+ pages = data->pages.pagevec;
+ while (!list_empty(head)) {
+ req = nfs_list_entry(head->next);
+ nfs_list_remove_request(req);
+ nfs_list_add_request(req, &hdr->pages);
+ *pages++ = req->wb_page;
+ }
+
+ if ((desc->pg_ioflags & FLUSH_COND_STABLE) &&
+ (desc->pg_moreio || nfs_reqs_to_commit(&cinfo)))
+ desc->pg_ioflags &= ~FLUSH_COND_STABLE;
+
+ /* Set up the argument struct */
+ nfs_pgio_rpcsetup(data, desc->pg_count, 0, desc->pg_ioflags, &cinfo);
+ hdr->data = data;
+ desc->pg_rpc_callops = &nfs_pgio_common_ops;
+ return 0;
+}
+EXPORT_SYMBOL_GPL(nfs_generic_pgio);
+
+static int nfs_generic_pg_pgios(struct nfs_pageio_descriptor *desc)
+{
+ struct nfs_rw_header *rw_hdr;
+ struct nfs_pgio_header *hdr;
+ int ret;
+
+ rw_hdr = nfs_rw_header_alloc(desc->pg_rw_ops);
+ if (!rw_hdr) {
+ desc->pg_completion_ops->error_cleanup(&desc->pg_list);
+ return -ENOMEM;
+ }
+ hdr = &rw_hdr->header;
+ nfs_pgheader_init(desc, hdr, nfs_rw_header_free);
+ atomic_inc(&hdr->refcnt);
+ ret = nfs_generic_pgio(desc, hdr);
+ if (ret == 0)
+ ret = nfs_initiate_pgio(NFS_CLIENT(hdr->inode),
+ hdr->data, desc->pg_rpc_callops,
+ desc->pg_ioflags, 0);
+ if (atomic_dec_and_test(&hdr->refcnt))
+ hdr->completion_ops->completion(hdr);
+ return ret;
+}
+
static bool nfs_match_open_context(const struct nfs_open_context *ctx1,
const struct nfs_open_context *ctx2)
{
@@ -356,18 +824,23 @@ static bool nfs_can_coalesce_requests(struct nfs_page *prev,
struct nfs_page *req,
struct nfs_pageio_descriptor *pgio)
{
- if (!nfs_match_open_context(req->wb_context, prev->wb_context))
- return false;
- if (req->wb_context->dentry->d_inode->i_flock != NULL &&
- !nfs_match_lock_context(req->wb_lock_context, prev->wb_lock_context))
- return false;
- if (req->wb_pgbase != 0)
- return false;
- if (prev->wb_pgbase + prev->wb_bytes != PAGE_CACHE_SIZE)
- return false;
- if (req_offset(req) != req_offset(prev) + prev->wb_bytes)
- return false;
- return pgio->pg_ops->pg_test(pgio, prev, req);
+ size_t size;
+
+ if (prev) {
+ if (!nfs_match_open_context(req->wb_context, prev->wb_context))
+ return false;
+ if (req->wb_context->dentry->d_inode->i_flock != NULL &&
+ !nfs_match_lock_context(req->wb_lock_context,
+ prev->wb_lock_context))
+ return false;
+ if (req_offset(req) != req_offset(prev) + prev->wb_bytes)
+ return false;
+ }
+ size = pgio->pg_ops->pg_test(pgio, prev, req);
+ WARN_ON_ONCE(size > req->wb_bytes);
+ if (size && size < req->wb_bytes)
+ req->wb_bytes = size;
+ return size > 0;
}
/**
@@ -381,17 +854,16 @@ static bool nfs_can_coalesce_requests(struct nfs_page *prev,
static int nfs_pageio_do_add_request(struct nfs_pageio_descriptor *desc,
struct nfs_page *req)
{
+ struct nfs_page *prev = NULL;
if (desc->pg_count != 0) {
- struct nfs_page *prev;
-
prev = nfs_list_entry(desc->pg_list.prev);
- if (!nfs_can_coalesce_requests(prev, req, desc))
- return 0;
} else {
if (desc->pg_ops->pg_init)
desc->pg_ops->pg_init(desc, req);
desc->pg_base = req->wb_pgbase;
}
+ if (!nfs_can_coalesce_requests(prev, req, desc))
+ return 0;
nfs_list_remove_request(req);
nfs_list_add_request(req, &desc->pg_list);
desc->pg_count += req->wb_bytes;
@@ -421,22 +893,73 @@ static void nfs_pageio_doio(struct nfs_pageio_descriptor *desc)
* @desc: destination io descriptor
* @req: request
*
+ * This may split a request into subrequests which are all part of the
+ * same page group.
+ *
* Returns true if the request 'req' was successfully coalesced into the
* existing list of pages 'desc'.
*/
static int __nfs_pageio_add_request(struct nfs_pageio_descriptor *desc,
struct nfs_page *req)
{
- while (!nfs_pageio_do_add_request(desc, req)) {
- desc->pg_moreio = 1;
- nfs_pageio_doio(desc);
- if (desc->pg_error < 0)
- return 0;
- desc->pg_moreio = 0;
- if (desc->pg_recoalesce)
- return 0;
- }
+ struct nfs_page *subreq;
+ unsigned int bytes_left = 0;
+ unsigned int offset, pgbase;
+
+ nfs_page_group_lock(req);
+
+ subreq = req;
+ bytes_left = subreq->wb_bytes;
+ offset = subreq->wb_offset;
+ pgbase = subreq->wb_pgbase;
+
+ do {
+ if (!nfs_pageio_do_add_request(desc, subreq)) {
+ /* make sure pg_test call(s) did nothing */
+ WARN_ON_ONCE(subreq->wb_bytes != bytes_left);
+ WARN_ON_ONCE(subreq->wb_offset != offset);
+ WARN_ON_ONCE(subreq->wb_pgbase != pgbase);
+
+ nfs_page_group_unlock(req);
+ desc->pg_moreio = 1;
+ nfs_pageio_doio(desc);
+ if (desc->pg_error < 0)
+ return 0;
+ desc->pg_moreio = 0;
+ if (desc->pg_recoalesce)
+ return 0;
+ /* retry add_request for this subreq */
+ nfs_page_group_lock(req);
+ continue;
+ }
+
+ /* check for buggy pg_test call(s) */
+ WARN_ON_ONCE(subreq->wb_bytes + subreq->wb_pgbase > PAGE_SIZE);
+ WARN_ON_ONCE(subreq->wb_bytes > bytes_left);
+ WARN_ON_ONCE(subreq->wb_bytes == 0);
+
+ bytes_left -= subreq->wb_bytes;
+ offset += subreq->wb_bytes;
+ pgbase += subreq->wb_bytes;
+
+ if (bytes_left) {
+ subreq = nfs_create_request(req->wb_context,
+ req->wb_page,
+ subreq, pgbase, bytes_left);
+ if (IS_ERR(subreq))
+ goto err_ptr;
+ nfs_lock_request(subreq);
+ subreq->wb_offset = offset;
+ subreq->wb_index = req->wb_index;
+ }
+ } while (bytes_left > 0);
+
+ nfs_page_group_unlock(req);
return 1;
+err_ptr:
+ desc->pg_error = PTR_ERR(subreq);
+ nfs_page_group_unlock(req);
+ return 0;
}
static int nfs_do_recoalesce(struct nfs_pageio_descriptor *desc)
@@ -535,3 +1058,13 @@ void nfs_destroy_nfspagecache(void)
kmem_cache_destroy(nfs_page_cachep);
}
+static const struct rpc_call_ops nfs_pgio_common_ops = {
+ .rpc_call_prepare = nfs_pgio_prepare,
+ .rpc_call_done = nfs_pgio_result,
+ .rpc_release = nfs_pgio_release,
+};
+
+const struct nfs_pageio_ops nfs_pgio_rw_ops = {
+ .pg_test = nfs_generic_pg_test,
+ .pg_doio = nfs_generic_pg_pgios,
+};