X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=fs%2Fnfs%2Fpagelist.c;h=345bb9b4765b6fee52fd8a0c76558c34e2fc1f1c;hb=c2319540cd7330fa9066e5b9b84d357a2c8631a2;hp=e12054c86d0dd349dd0750e4dd92e44c6f2e9399;hpb=3cb7396b7b26585b1ab7c1a8ca554ec103da5d37;p=linux-2.6 diff --git a/fs/nfs/pagelist.c b/fs/nfs/pagelist.c index e12054c86d..345bb9b476 100644 --- a/fs/nfs/pagelist.c +++ b/fs/nfs/pagelist.c @@ -11,6 +11,7 @@ #include #include +#include #include #include #include @@ -84,9 +85,8 @@ nfs_create_request(struct nfs_open_context *ctx, struct inode *inode, req->wb_offset = offset; req->wb_pgbase = offset; req->wb_bytes = count; - atomic_set(&req->wb_count, 1); req->wb_context = get_nfs_open_context(ctx); - + kref_init(&req->wb_kref); return req; } @@ -108,30 +108,31 @@ void nfs_unlock_request(struct nfs_page *req) } /** - * nfs_set_page_writeback_locked - Lock a request for writeback + * nfs_set_page_tag_locked - Tag a request as locked * @req: */ -int nfs_set_page_writeback_locked(struct nfs_page *req) +static int nfs_set_page_tag_locked(struct nfs_page *req) { - struct nfs_inode *nfsi = NFS_I(req->wb_context->dentry->d_inode); + struct nfs_inode *nfsi = NFS_I(req->wb_context->path.dentry->d_inode); if (!nfs_lock_request(req)) return 0; - radix_tree_tag_set(&nfsi->nfs_page_tree, req->wb_index, NFS_PAGE_TAG_WRITEBACK); + radix_tree_tag_set(&nfsi->nfs_page_tree, req->wb_index, NFS_PAGE_TAG_LOCKED); return 1; } /** - * nfs_clear_page_writeback - Unlock request and wake up sleepers + * nfs_clear_page_tag_locked - Clear request tag and wake up sleepers */ -void nfs_clear_page_writeback(struct nfs_page *req) +void nfs_clear_page_tag_locked(struct nfs_page *req) { - struct nfs_inode *nfsi = NFS_I(req->wb_context->dentry->d_inode); + struct inode *inode = req->wb_context->path.dentry->d_inode; + struct nfs_inode *nfsi = NFS_I(inode); if (req->wb_page != NULL) { - spin_lock(&nfsi->req_lock); - radix_tree_tag_clear(&nfsi->nfs_page_tree, req->wb_index, NFS_PAGE_TAG_WRITEBACK); - spin_unlock(&nfsi->req_lock); + spin_lock(&inode->i_lock); + radix_tree_tag_clear(&nfsi->nfs_page_tree, req->wb_index, NFS_PAGE_TAG_LOCKED); + spin_unlock(&inode->i_lock); } nfs_unlock_request(req); } @@ -159,11 +160,9 @@ void nfs_clear_request(struct nfs_page *req) * * Note: Should never be called with the spinlock held! */ -void -nfs_release_request(struct nfs_page *req) +static void nfs_free_request(struct kref *kref) { - if (!atomic_dec_and_test(&req->wb_count)) - return; + struct nfs_page *req = container_of(kref, struct nfs_page, wb_kref); /* Release struct file or cached credential */ nfs_clear_request(req); @@ -171,6 +170,11 @@ nfs_release_request(struct nfs_page *req) nfs_page_free(req); } +void nfs_release_request(struct nfs_page *req) +{ + kref_put(&req->wb_kref, nfs_free_request); +} + static int nfs_wait_bit_interruptible(void *word) { int ret = 0; @@ -192,7 +196,7 @@ static int nfs_wait_bit_interruptible(void *word) int nfs_wait_on_request(struct nfs_page *req) { - struct rpc_clnt *clnt = NFS_CLIENT(req->wb_context->dentry->d_inode); + struct rpc_clnt *clnt = NFS_CLIENT(req->wb_context->path.dentry->d_inode); sigset_t oldmask; int ret = 0; @@ -354,24 +358,44 @@ void nfs_pageio_complete(struct nfs_pageio_descriptor *desc) nfs_pageio_doio(desc); } +/** + * nfs_pageio_cond_complete - Conditional I/O completion + * @desc: pointer to io descriptor + * @index: page index + * + * It is important to ensure that processes don't try to take locks + * on non-contiguous ranges of pages as that might deadlock. This + * function should be called before attempting to wait on a locked + * nfs_page. It will complete the I/O if the page index 'index' + * is not contiguous with the existing list of pages in 'desc'. + */ +void nfs_pageio_cond_complete(struct nfs_pageio_descriptor *desc, pgoff_t index) +{ + if (!list_empty(&desc->pg_list)) { + struct nfs_page *prev = nfs_list_entry(desc->pg_list.prev); + if (index != prev->wb_index + 1) + nfs_pageio_doio(desc); + } +} + #define NFS_SCAN_MAXENTRIES 16 /** * nfs_scan_list - Scan a list for matching requests * @nfsi: NFS inode - * @head: One of the NFS inode request lists * @dst: Destination list * @idx_start: lower bound of page->index to scan * @npages: idx_start + npages sets the upper bound to scan. + * @tag: tag to scan for * * Moves elements from one of the inode request lists. * If the number of requests is set to 0, the entire address_space * starting at index idx_start, is scanned. * The requests are *not* checked to ensure that they form a contiguous set. - * You must be holding the inode's req_lock when calling this function + * You must be holding the inode's i_lock when calling this function */ -int nfs_scan_list(struct nfs_inode *nfsi, struct list_head *head, +int nfs_scan_list(struct nfs_inode *nfsi, struct list_head *dst, pgoff_t idx_start, - unsigned int npages) + unsigned int npages, int tag) { struct nfs_page *pgvec[NFS_SCAN_MAXENTRIES]; struct nfs_page *req; @@ -386,9 +410,9 @@ int nfs_scan_list(struct nfs_inode *nfsi, struct list_head *head, idx_end = idx_start + npages - 1; for (;;) { - found = radix_tree_gang_lookup(&nfsi->nfs_page_tree, + found = radix_tree_gang_lookup_tag(&nfsi->nfs_page_tree, (void **)&pgvec[0], idx_start, - NFS_SCAN_MAXENTRIES); + NFS_SCAN_MAXENTRIES, tag); if (found <= 0) break; for (i = 0; i < found; i++) { @@ -396,15 +420,18 @@ int nfs_scan_list(struct nfs_inode *nfsi, struct list_head *head, if (req->wb_index > idx_end) goto out; idx_start = req->wb_index + 1; - if (req->wb_list_head != head) - continue; - if (nfs_set_page_writeback_locked(req)) { + if (nfs_set_page_tag_locked(req)) { nfs_list_remove_request(req); + radix_tree_tag_clear(&nfsi->nfs_page_tree, + req->wb_index, tag); nfs_list_add_request(req, dst); res++; + if (res == INT_MAX) + goto out; } } - + /* for latency reduction */ + cond_resched_lock(&nfsi->vfs_inode.i_lock); } out: return res; @@ -415,7 +442,7 @@ int __init nfs_init_nfspagecache(void) nfs_page_cachep = kmem_cache_create("nfs_page", sizeof(struct nfs_page), 0, SLAB_HWCACHE_ALIGN, - NULL, NULL); + NULL); if (nfs_page_cachep == NULL) return -ENOMEM;