diff options
| -rw-r--r-- | fs/nfs/pagelist.c | 117 | ||||
| -rw-r--r-- | fs/nfs/read.c | 24 | ||||
| -rw-r--r-- | fs/nfs/write.c | 11 | ||||
| -rw-r--r-- | include/linux/nfs_page.h | 13 |
4 files changed, 114 insertions, 51 deletions
diff --git a/fs/nfs/pagelist.c b/fs/nfs/pagelist.c index ca4b1d4ff42b..7017eb0e0bc8 100644 --- a/fs/nfs/pagelist.c +++ b/fs/nfs/pagelist.c @@ -223,48 +223,101 @@ out: } /** - * nfs_coalesce_requests - Split coalesced requests out from a list. + * nfs_pageio_init - initialise a page io descriptor + * @desc: pointer to descriptor + * @iosize: io block size + */ +void nfs_pageio_init(struct nfs_pageio_descriptor *desc, unsigned int bsize) +{ + INIT_LIST_HEAD(&desc->pg_list); + desc->pg_count = 0; + desc->pg_bsize = bsize; + desc->pg_base = 0; +} + +/** + * nfs_can_coalesce_requests - test two requests for compatibility + * @prev: pointer to nfs_page + * @req: pointer to nfs_page + * + * The nfs_page structures 'prev' and 'req' are compared to ensure that the + * page data area they describe is contiguous, and that their RPC + * credentials, NFSv4 open state, and lockowners are the same. + * + * Return 'true' if this is the case, else return 'false'. + */ +static int nfs_can_coalesce_requests(struct nfs_page *prev, + struct nfs_page *req) +{ + if (req->wb_context->cred != prev->wb_context->cred) + return 0; + if (req->wb_context->lockowner != prev->wb_context->lockowner) + return 0; + if (req->wb_context->state != prev->wb_context->state) + return 0; + if (req->wb_index != (prev->wb_index + 1)) + return 0; + if (req->wb_pgbase != 0) + return 0; + if (prev->wb_pgbase + prev->wb_bytes != PAGE_CACHE_SIZE) + return 0; + return 1; +} + +/** + * nfs_pageio_add_request - Attempt to coalesce a request into a page list. + * @desc: destination io descriptor + * @req: request + * + * 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) +{ + size_t newlen = req->wb_bytes; + + if (desc->pg_count != 0) { + struct nfs_page *prev; + + /* + * 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. + */ + newlen += desc->pg_count; + if (desc->pg_base + newlen > desc->pg_bsize) + return 0; + prev = nfs_list_entry(desc->pg_list.prev); + if (!nfs_can_coalesce_requests(prev, req)) + return 0; + } else + desc->pg_base = req->wb_pgbase; + nfs_list_remove_request(req); + nfs_list_add_request(req, &desc->pg_list); + desc->pg_count = newlen; + return 1; +} + +/** + * nfs_pageio_add_list - Split coalesced requests out from a list. + * @desc: destination io descriptor * @head: source list - * @dst: destination list - * @nmax: maximum number of requests to coalesce * * Moves a maximum of 'nmax' elements from one list to another. * The elements are checked to ensure that they form a contiguous set * of pages, and that the RPC credentials are the same. */ -int -nfs_coalesce_requests(struct list_head *head, struct list_head *dst, - unsigned int nmax) +void nfs_pageio_add_list(struct nfs_pageio_descriptor *desc, + struct list_head *head) { - struct nfs_page *req = NULL; - unsigned int npages = 0; - while (!list_empty(head)) { - struct nfs_page *prev = req; - - req = nfs_list_entry(head->next); - if (prev) { - if (req->wb_context->cred != prev->wb_context->cred) - break; - if (req->wb_context->lockowner != prev->wb_context->lockowner) - break; - if (req->wb_context->state != prev->wb_context->state) - break; - if (req->wb_index != (prev->wb_index + 1)) - break; - - if (req->wb_pgbase != 0) - break; - } - nfs_list_remove_request(req); - nfs_list_add_request(req, dst); - npages++; - if (req->wb_pgbase + req->wb_bytes != PAGE_CACHE_SIZE) - break; - if (npages >= nmax) + struct nfs_page *req = nfs_list_entry(head->next); + if (!nfs_pageio_add_request(desc, req)) break; } - return npages; } #define NFS_SCAN_MAXENTRIES 16 diff --git a/fs/nfs/read.c b/fs/nfs/read.c index 6ab4d5a9edf2..97f0f42e136d 100644 --- a/fs/nfs/read.c +++ b/fs/nfs/read.c @@ -328,24 +328,26 @@ out_bad: } static int -nfs_pagein_list(struct list_head *head, int rpages) +nfs_pagein_list(struct list_head *head, unsigned int rsize) { - LIST_HEAD(one_request); - struct nfs_page *req; - int error = 0; - unsigned int pages = 0; + struct nfs_pageio_descriptor desc; + struct nfs_page *req; + unsigned int pages = 0; + int error = 0; while (!list_empty(head)) { - pages += nfs_coalesce_requests(head, &one_request, rpages); - req = nfs_list_entry(one_request.next); - error = nfs_pagein_one(&one_request, req->wb_context->dentry->d_inode); + nfs_pageio_init(&desc, rsize); + nfs_pageio_add_list(&desc, head); + req = nfs_list_entry(desc.pg_list.next); + error = nfs_pagein_one(&desc.pg_list, req->wb_context->dentry->d_inode); if (error < 0) break; + pages += (desc.pg_count + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT; } - if (error >= 0) - return pages; nfs_async_read_error(head); + if (error >= 0) + return pages; return error; } @@ -595,7 +597,7 @@ int nfs_readpages(struct file *filp, struct address_space *mapping, filp->private_data); ret = read_cache_pages(mapping, pages, readpage_async_filler, &desc); if (!list_empty(&head)) { - int err = nfs_pagein_list(&head, server->rpages); + int err = nfs_pagein_list(&head, server->rsize); if (!ret) nfs_add_stats(inode, NFSIOS_READPAGES, err); ret = err; diff --git a/fs/nfs/write.c b/fs/nfs/write.c index dbad89c8e427..b03ec1ba4d75 100644 --- a/fs/nfs/write.c +++ b/fs/nfs/write.c @@ -945,9 +945,8 @@ static int nfs_flush_one(struct inode *inode, struct list_head *head, int how) static int nfs_flush_list(struct inode *inode, struct list_head *head, int npages, int how) { - LIST_HEAD(one_request); + struct nfs_pageio_descriptor desc; int (*flush_one)(struct inode *, struct list_head *, int); - struct nfs_page *req; int wpages = NFS_SERVER(inode)->wpages; int wsize = NFS_SERVER(inode)->wsize; int error; @@ -961,16 +960,16 @@ static int nfs_flush_list(struct inode *inode, struct list_head *head, int npage how |= FLUSH_STABLE; do { - nfs_coalesce_requests(head, &one_request, wpages); - req = nfs_list_entry(one_request.next); - error = flush_one(inode, &one_request, how); + nfs_pageio_init(&desc, wsize); + nfs_pageio_add_list(&desc, head); + error = flush_one(inode, &desc.pg_list, how); if (error < 0) goto out_err; } while (!list_empty(head)); return 0; out_err: while (!list_empty(head)) { - req = nfs_list_entry(head->next); + struct nfs_page *req = nfs_list_entry(head->next); nfs_list_remove_request(req); nfs_redirty_request(req); nfs_end_page_writeback(req->wb_page); diff --git a/include/linux/nfs_page.h b/include/linux/nfs_page.h index 16b0266b14fd..3ef8e0441473 100644 --- a/include/linux/nfs_page.h +++ b/include/linux/nfs_page.h @@ -48,6 +48,13 @@ struct nfs_page { struct nfs_writeverf wb_verf; /* Commit cookie */ }; +struct nfs_pageio_descriptor { + struct list_head pg_list; + size_t pg_count; + size_t pg_bsize; + unsigned int pg_base; +}; + #define NFS_WBACK_BUSY(req) (test_bit(PG_BUSY,&(req)->wb_flags)) extern struct nfs_page *nfs_create_request(struct nfs_open_context *ctx, @@ -64,8 +71,10 @@ extern long nfs_scan_dirty(struct address_space *mapping, struct list_head *dst); extern int nfs_scan_list(struct nfs_inode *nfsi, struct list_head *head, struct list_head *dst, unsigned long idx_start, unsigned int npages); -extern int nfs_coalesce_requests(struct list_head *, struct list_head *, - unsigned int); +extern void nfs_pageio_init(struct nfs_pageio_descriptor *desc, + size_t iosize); +extern void nfs_pageio_add_list(struct nfs_pageio_descriptor *, + struct list_head *); extern int nfs_wait_on_request(struct nfs_page *); extern void nfs_unlock_request(struct nfs_page *req); extern int nfs_set_page_writeback_locked(struct nfs_page *req); |