From c917cfaf9bbef44dd35b75b8fb772a44798a1cf2 Mon Sep 17 00:00:00 2001 From: Trond Myklebust Date: Sun, 7 Apr 2019 13:59:06 -0400 Subject: [PATCH] NFS: Fix up NFS I/O subrequest creation We require all NFS I/O subrequests to duplicate the lock context as well as the open context. Signed-off-by: Trond Myklebust Signed-off-by: Anna Schumaker --- fs/nfs/pagelist.c | 93 ++++++++++++++++++++++++++++++++----------------------- 1 file changed, 55 insertions(+), 38 deletions(-) diff --git a/fs/nfs/pagelist.c b/fs/nfs/pagelist.c index e9f39fa5964b..66a5c5d4a777 100644 --- a/fs/nfs/pagelist.c +++ b/fs/nfs/pagelist.c @@ -295,25 +295,13 @@ out: nfs_release_request(head); } -/** - * nfs_create_request - Create an NFS read/write request. - * @ctx: open context to use - * @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 - * - * The page must be locked by the caller. This makes sure we never - * create two different requests for the same page. - * User should ensure it is safe to sleep in this function. - */ -struct nfs_page * -nfs_create_request(struct nfs_open_context *ctx, struct page *page, - struct nfs_page *last, unsigned int offset, - unsigned int count) +static struct nfs_page * +__nfs_create_request(struct nfs_lock_context *l_ctx, struct page *page, + struct nfs_page *last, unsigned int pgbase, + unsigned int offset, unsigned int count) { struct nfs_page *req; - struct nfs_lock_context *l_ctx; + struct nfs_open_context *ctx = l_ctx->open_context; if (test_bit(NFS_CONTEXT_BAD, &ctx->flags)) return ERR_PTR(-EBADF); @@ -322,13 +310,8 @@ nfs_create_request(struct nfs_open_context *ctx, struct page *page, if (req == NULL) return ERR_PTR(-ENOMEM); - /* get lock context early so we can deal with alloc failures */ - l_ctx = nfs_get_lock_context(ctx); - if (IS_ERR(l_ctx)) { - nfs_page_free(req); - return ERR_CAST(l_ctx); - } req->wb_lock_context = l_ctx; + refcount_inc(&l_ctx->count); atomic_inc(&l_ctx->io_count); /* Initialize the request struct. Initially, we assume a @@ -340,7 +323,7 @@ nfs_create_request(struct nfs_open_context *ctx, struct page *page, get_page(page); } req->wb_offset = offset; - req->wb_pgbase = offset; + req->wb_pgbase = pgbase; req->wb_bytes = count; req->wb_context = get_nfs_open_context(ctx); kref_init(&req->wb_kref); @@ -349,6 +332,49 @@ nfs_create_request(struct nfs_open_context *ctx, struct page *page, } /** + * nfs_create_request - Create an NFS read/write request. + * @ctx: open context to use + * @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 + * + * The page must be locked by the caller. This makes sure we never + * create two different requests for the same page. + * User should ensure it is safe to sleep in this function. + */ +struct nfs_page * +nfs_create_request(struct nfs_open_context *ctx, struct page *page, + struct nfs_page *last, unsigned int offset, + unsigned int count) +{ + struct nfs_lock_context *l_ctx = nfs_get_lock_context(ctx); + struct nfs_page *ret; + + if (IS_ERR(l_ctx)) + return ERR_CAST(l_ctx); + ret = __nfs_create_request(l_ctx, page, last, offset, offset, count); + nfs_put_lock_context(l_ctx); + return ret; +} + +static struct nfs_page * +nfs_create_subreq(struct nfs_page *req, struct nfs_page *last, + unsigned int pgbase, unsigned int offset, + unsigned int count) +{ + struct nfs_page *ret; + + ret = __nfs_create_request(req->wb_lock_context, req->wb_page, last, + pgbase, offset, count); + if (!IS_ERR(ret)) { + nfs_lock_request(ret); + ret->wb_index = req->wb_index; + } + return ret; +} + +/** * nfs_unlock_request - Unlock request and wake up sleepers. * @req: pointer to request */ @@ -1049,14 +1075,10 @@ static int __nfs_pageio_add_request(struct nfs_pageio_descriptor *desc, pgbase += subreq->wb_bytes; if (bytes_left) { - subreq = nfs_create_request(req->wb_context, - req->wb_page, - subreq, pgbase, bytes_left); + subreq = nfs_create_subreq(req, subreq, pgbase, + offset, 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); @@ -1158,19 +1180,14 @@ int nfs_pageio_add_request(struct nfs_pageio_descriptor *desc, lastreq = lastreq->wb_this_page) ; - dupreq = nfs_create_request(req->wb_context, - req->wb_page, lastreq, pgbase, bytes); + dupreq = nfs_create_subreq(req, lastreq, + pgbase, offset, bytes); + nfs_page_group_unlock(req); if (IS_ERR(dupreq)) { - nfs_page_group_unlock(req); desc->pg_error = PTR_ERR(dupreq); goto out_failed; } - - nfs_lock_request(dupreq); - nfs_page_group_unlock(req); - dupreq->wb_offset = offset; - dupreq->wb_index = req->wb_index; } else dupreq = req; -- 2.11.0