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| author | Trond Myklebust <Trond.Myklebust@netapp.com> | 2007-05-20 13:05:05 -0400 |
|---|---|---|
| committer | Trond Myklebust <Trond.Myklebust@netapp.com> | 2007-07-10 23:40:23 -0400 |
| commit | de05a0cc2a2ae16eb8d8dbf88fe728ace45beb9a (patch) | |
| tree | 363a6afc01a935d9e34b3559235687f8fec4d512 | |
| parent | 44dd151d5c21234cc534c47d7382f5c28c3143cd (diff) | |
| download | linux-de05a0cc2a2ae16eb8d8dbf88fe728ace45beb9a.tar.bz2 | |
NFS: Minor read optimisation...
Since PG_uptodate may now end up getting set during the call to
nfs_wb_page(), we can avoid putting a read request on the wire in those
situations.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
| -rw-r--r-- | fs/nfs/read.c | 34 |
1 files changed, 23 insertions, 11 deletions
diff --git a/fs/nfs/read.c b/fs/nfs/read.c index 7bd7cb95c034..c07d0d10d9ed 100644 --- a/fs/nfs/read.c +++ b/fs/nfs/read.c @@ -483,17 +483,19 @@ int nfs_readpage(struct file *file, struct page *page) */ error = nfs_wb_page(inode, page); if (error) - goto out_error; + goto out_unlock; + if (PageUptodate(page)) + goto out_unlock; error = -ESTALE; if (NFS_STALE(inode)) - goto out_error; + goto out_unlock; if (file == NULL) { error = -EBADF; ctx = nfs_find_open_context(inode, NULL, FMODE_READ); if (ctx == NULL) - goto out_error; + goto out_unlock; } else ctx = get_nfs_open_context((struct nfs_open_context *) file->private_data); @@ -502,8 +504,7 @@ int nfs_readpage(struct file *file, struct page *page) put_nfs_open_context(ctx); return error; - -out_error: +out_unlock: unlock_page(page); return error; } @@ -520,21 +521,32 @@ readpage_async_filler(void *data, struct page *page) struct inode *inode = page->mapping->host; struct nfs_page *new; unsigned int len; + int error; + + error = nfs_wb_page(inode, page); + if (error) + goto out_unlock; + if (PageUptodate(page)) + goto out_unlock; - nfs_wb_page(inode, page); len = nfs_page_length(page); if (len == 0) return nfs_return_empty_page(page); + new = nfs_create_request(desc->ctx, inode, page, 0, len); - if (IS_ERR(new)) { - SetPageError(page); - unlock_page(page); - return PTR_ERR(new); - } + if (IS_ERR(new)) + goto out_error; + if (len < PAGE_CACHE_SIZE) zero_user_page(page, len, PAGE_CACHE_SIZE - len, KM_USER0); nfs_pageio_add_request(desc->pgio, new); return 0; +out_error: + error = PTR_ERR(new); + SetPageError(page); +out_unlock: + unlock_page(page); + return error; } int nfs_readpages(struct file *filp, struct address_space *mapping, |