From c5fab6f4f081afcfcd7c1d444d9b900d6ef3e50b Mon Sep 17 00:00:00 2001 From: Jeff Layton Date: Wed, 19 Sep 2012 06:22:30 -0700 Subject: [PATCH] cifs: turn the pages list in cifs_readdata into an array We'll need an array to put into a smb_rqst, so convert this into an array instead of (ab)using the lru list_head. Signed-off-by: Jeff Layton --- fs/cifs/cifsglob.h | 3 +- fs/cifs/file.c | 87 ++++++++++++++++++++++++++-------------------- 2 files changed, 52 insertions(+), 38 deletions(-) diff --git a/fs/cifs/cifsglob.h b/fs/cifs/cifsglob.h index 737289b50ca5..b70863ebedf2 100644 --- a/fs/cifs/cifsglob.h +++ b/fs/cifs/cifsglob.h @@ -977,12 +977,13 @@ struct cifs_readdata { unsigned int bytes; pid_t pid; int result; - struct list_head pages; struct work_struct work; int (*marshal_iov) (struct cifs_readdata *rdata, unsigned int remaining); unsigned int nr_iov; struct kvec *iov; + unsigned int nr_pages; + struct page *pages[]; }; struct cifs_writedata; diff --git a/fs/cifs/file.c b/fs/cifs/file.c index 61b7c834069f..6eaf48270c97 100644 --- a/fs/cifs/file.c +++ b/fs/cifs/file.c @@ -2419,13 +2419,13 @@ cifs_readdata_alloc(unsigned int nr_pages, work_func_t complete) if (!iov) return (struct cifs_readdata *)iov; - rdata = kzalloc(sizeof(*rdata), GFP_KERNEL); + rdata = kzalloc(sizeof(*rdata) + (sizeof(struct page *) * nr_pages), + GFP_KERNEL); if (rdata != NULL) { kref_init(&rdata->refcount); INIT_LIST_HEAD(&rdata->list); init_completion(&rdata->done); INIT_WORK(&rdata->work, complete); - INIT_LIST_HEAD(&rdata->pages); rdata->iov = iov; } else { kfree(iov); @@ -2448,25 +2448,25 @@ cifs_readdata_release(struct kref *refcount) } static int -cifs_read_allocate_pages(struct list_head *list, unsigned int npages) +cifs_read_allocate_pages(struct cifs_readdata *rdata, unsigned int nr_pages) { int rc = 0; - struct page *page, *tpage; + struct page *page; unsigned int i; - for (i = 0; i < npages; i++) { + for (i = 0; i < nr_pages; i++) { page = alloc_page(GFP_KERNEL|__GFP_HIGHMEM); if (!page) { rc = -ENOMEM; break; } - list_add(&page->lru, list); + rdata->pages[i] = page; } if (rc) { - list_for_each_entry_safe(page, tpage, list, lru) { - list_del(&page->lru); - put_page(page); + for (i = 0; i < nr_pages; i++) { + put_page(rdata->pages[i]); + rdata->pages[i] = NULL; } } return rc; @@ -2475,13 +2475,13 @@ cifs_read_allocate_pages(struct list_head *list, unsigned int npages) static void cifs_uncached_readdata_release(struct kref *refcount) { - struct page *page, *tpage; struct cifs_readdata *rdata = container_of(refcount, struct cifs_readdata, refcount); + unsigned int i; - list_for_each_entry_safe(page, tpage, &rdata->pages, lru) { - list_del(&page->lru); - put_page(page); + for (i = 0; i < rdata->nr_pages; i++) { + put_page(rdata->pages[i]); + rdata->pages[i] = NULL; } cifs_readdata_release(refcount); } @@ -2525,17 +2525,18 @@ cifs_readdata_to_iov(struct cifs_readdata *rdata, const struct iovec *iov, int rc = 0; struct iov_iter ii; size_t pos = rdata->offset - offset; - struct page *page, *tpage; ssize_t remaining = rdata->bytes; unsigned char *pdata; + unsigned int i; /* set up iov_iter and advance to the correct offset */ iov_iter_init(&ii, iov, nr_segs, iov_length(iov, nr_segs), 0); iov_iter_advance(&ii, pos); *copied = 0; - list_for_each_entry_safe(page, tpage, &rdata->pages, lru) { + for (i = 0; i < rdata->nr_pages; i++) { ssize_t copy; + struct page *page = rdata->pages[i]; /* copy a whole page or whatever's left */ copy = min_t(ssize_t, remaining, PAGE_SIZE); @@ -2555,9 +2556,6 @@ cifs_readdata_to_iov(struct cifs_readdata *rdata, const struct iovec *iov, iov_iter_advance(&ii, copy); } } - - list_del(&page->lru); - put_page(page); } return rc; @@ -2568,13 +2566,12 @@ cifs_uncached_readv_complete(struct work_struct *work) { struct cifs_readdata *rdata = container_of(work, struct cifs_readdata, work); + unsigned int i; /* if the result is non-zero then the pages weren't kmapped */ if (rdata->result == 0) { - struct page *page; - - list_for_each_entry(page, &rdata->pages, lru) - kunmap(page); + for (i = 0; i < rdata->nr_pages; i++) + kunmap(rdata->pages[i]); } complete(&rdata->done); @@ -2586,10 +2583,13 @@ cifs_uncached_read_marshal_iov(struct cifs_readdata *rdata, unsigned int remaining) { int len = 0; - struct page *page, *tpage; + unsigned int i; + unsigned int nr_pages = rdata->nr_pages; rdata->nr_iov = 1; - list_for_each_entry_safe(page, tpage, &rdata->pages, lru) { + for (i = 0; i < nr_pages; i++) { + struct page *page = rdata->pages[i]; + if (remaining >= PAGE_SIZE) { /* enough data to fill the page */ rdata->iov[rdata->nr_iov].iov_base = kmap(page); @@ -2616,7 +2616,8 @@ cifs_uncached_read_marshal_iov(struct cifs_readdata *rdata, remaining = 0; } else { /* no need to hold page hostage */ - list_del(&page->lru); + rdata->pages[i] = NULL; + rdata->nr_pages--; put_page(page); } } @@ -2675,11 +2676,12 @@ cifs_iovec_read(struct file *file, const struct iovec *iov, goto error; } - rc = cifs_read_allocate_pages(&rdata->pages, npages); + rc = cifs_read_allocate_pages(rdata, npages); if (rc) goto error; rdata->cfile = cifsFileInfo_get(open_file); + rdata->nr_pages = npages; rdata->offset = offset; rdata->bytes = cur_len; rdata->pid = pid; @@ -2923,12 +2925,13 @@ int cifs_file_mmap(struct file *file, struct vm_area_struct *vma) static void cifs_readv_complete(struct work_struct *work) { + unsigned int i; struct cifs_readdata *rdata = container_of(work, struct cifs_readdata, work); - struct page *page, *tpage; - list_for_each_entry_safe(page, tpage, &rdata->pages, lru) { - list_del(&page->lru); + for (i = 0; i < rdata->nr_pages; i++) { + struct page *page = rdata->pages[i]; + lru_cache_add_file(page); if (rdata->result == 0) { @@ -2943,6 +2946,7 @@ cifs_readv_complete(struct work_struct *work) cifs_readpage_to_fscache(rdata->mapping->host, page); page_cache_release(page); + rdata->pages[i] = NULL; } kref_put(&rdata->refcount, cifs_readdata_release); } @@ -2951,9 +2955,10 @@ static int cifs_readpages_marshal_iov(struct cifs_readdata *rdata, unsigned int remaining) { int len = 0; - struct page *page, *tpage; + unsigned int i; u64 eof; pgoff_t eof_index; + unsigned int nr_pages = rdata->nr_pages; /* determine the eof that the server (probably) has */ eof = CIFS_I(rdata->mapping->host)->server_eof; @@ -2961,7 +2966,9 @@ cifs_readpages_marshal_iov(struct cifs_readdata *rdata, unsigned int remaining) cFYI(1, "eof=%llu eof_index=%lu", eof, eof_index); rdata->nr_iov = 1; - list_for_each_entry_safe(page, tpage, &rdata->pages, lru) { + for (i = 0; i < nr_pages; i++) { + struct page *page = rdata->pages[i]; + if (remaining >= PAGE_CACHE_SIZE) { /* enough data to fill the page */ rdata->iov[rdata->nr_iov].iov_base = kmap(page); @@ -2996,18 +3003,20 @@ cifs_readpages_marshal_iov(struct cifs_readdata *rdata, unsigned int remaining) * fill them until the writes are flushed. */ zero_user(page, 0, PAGE_CACHE_SIZE); - list_del(&page->lru); lru_cache_add_file(page); flush_dcache_page(page); SetPageUptodate(page); unlock_page(page); page_cache_release(page); + rdata->pages[i] = NULL; + rdata->nr_pages--; } else { /* no need to hold page hostage */ - list_del(&page->lru); lru_cache_add_file(page); unlock_page(page); page_cache_release(page); + rdata->pages[i] = NULL; + rdata->nr_pages--; } } @@ -3065,6 +3074,7 @@ static int cifs_readpages(struct file *file, struct address_space *mapping, * the rdata->pages, then we want them in increasing order. */ while (!list_empty(page_list)) { + unsigned int i; unsigned int bytes = PAGE_CACHE_SIZE; unsigned int expected_index; unsigned int nr_pages = 1; @@ -3135,13 +3145,16 @@ static int cifs_readpages(struct file *file, struct address_space *mapping, rdata->bytes = bytes; rdata->pid = pid; rdata->marshal_iov = cifs_readpages_marshal_iov; - list_splice_init(&tmplist, &rdata->pages); + + list_for_each_entry_safe(page, tpage, &tmplist, lru) { + list_del(&page->lru); + rdata->pages[rdata->nr_pages++] = page; + } rc = cifs_retry_async_readv(rdata); if (rc != 0) { - list_for_each_entry_safe(page, tpage, &rdata->pages, - lru) { - list_del(&page->lru); + for (i = 0; i < rdata->nr_pages; i++) { + page = rdata->pages[i]; lru_cache_add_file(page); unlock_page(page); page_cache_release(page);