From: Trond Myklebust Date: Tue, 5 Dec 2006 00:35:38 -0500 NFS: Cleanup: add common helper nfs_page_length() Clean up a lot of ad-hoc page length calculations in fs/nfs/write.c Signed-off-by: Trond Myklebust --- fs/nfs/internal.h | 18 +++++++++++++++++ fs/nfs/read.c | 21 +++----------------- fs/nfs/write.c | 55 ++++++++++------------------------------------------- 3 files changed, 31 insertions(+), 63 deletions(-) diff --git a/fs/nfs/internal.h b/fs/nfs/internal.h index d205466..a28f6ce 100644 --- a/fs/nfs/internal.h +++ b/fs/nfs/internal.h @@ -217,3 +217,21 @@ void nfs_super_set_maxbytes(struct super if (sb->s_maxbytes > MAX_LFS_FILESIZE || sb->s_maxbytes <= 0) sb->s_maxbytes = MAX_LFS_FILESIZE; } + +/* + * Determine the number of bytes of data the page contains + */ +static inline +unsigned int nfs_page_length(struct page *page) +{ + loff_t i_size = i_size_read(page->mapping->host); + + if (i_size > 0) { + pgoff_t end_index = (i_size - 1) >> PAGE_CACHE_SHIFT; + if (page->index < end_index) + return PAGE_CACHE_SIZE; + if (page->index == end_index) + return ((i_size - 1) & ~PAGE_CACHE_MASK) + 1; + } + return 0; +} diff --git a/fs/nfs/read.c b/fs/nfs/read.c index cca9fa2..05cca66 100644 --- a/fs/nfs/read.c +++ b/fs/nfs/read.c @@ -30,6 +30,7 @@ #include #include +#include "internal.h" #include "iostat.h" #define NFSDBG_FACILITY NFSDBG_PAGECACHE @@ -84,22 +85,6 @@ void nfs_readdata_release(void *data) } static -unsigned int nfs_page_length(struct inode *inode, struct page *page) -{ - loff_t i_size = i_size_read(inode); - unsigned long idx; - - if (i_size <= 0) - return 0; - idx = (i_size - 1) >> PAGE_CACHE_SHIFT; - if (page->index > idx) - return 0; - if (page->index != idx) - return PAGE_CACHE_SIZE; - return 1 + ((i_size - 1) & (PAGE_CACHE_SIZE - 1)); -} - -static int nfs_return_empty_page(struct page *page) { memclear_highpage_flush(page, 0, PAGE_CACHE_SIZE); @@ -231,7 +216,7 @@ static int nfs_readpage_async(struct nfs struct nfs_page *new; unsigned int len; - len = nfs_page_length(inode, page); + len = nfs_page_length(page); if (len == 0) return nfs_return_empty_page(page); new = nfs_create_request(ctx, inode, page, 0, len); @@ -667,7 +652,7 @@ readpage_async_filler(void *data, struct unsigned int len; nfs_wb_page(inode, page); - len = nfs_page_length(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); diff --git a/fs/nfs/write.c b/fs/nfs/write.c index 6df8319..3f6ca52 100644 --- a/fs/nfs/write.c +++ b/fs/nfs/write.c @@ -63,6 +63,7 @@ #include #include #include "delegation.h" +#include "internal.h" #include "iostat.h" #define NFSDBG_FACILITY NFSDBG_PAGECACHE @@ -199,30 +200,15 @@ static void nfs_grow_file(struct page *p */ static void nfs_mark_uptodate(struct page *page, unsigned int base, unsigned int count) { - loff_t end_offs; - if (PageUptodate(page)) return; if (base != 0) return; - if (count == PAGE_CACHE_SIZE) { - SetPageUptodate(page); - return; - } - - end_offs = i_size_read(page->mapping->host) - 1; - if (end_offs < 0) - return; - /* Is this the last page? */ - if (page->index != (unsigned long)(end_offs >> PAGE_CACHE_SHIFT)) + if (count != nfs_page_length(page)) return; - /* This is the last page: set PG_uptodate if we cover the entire - * extent of the data, then zero the rest of the page. - */ - if (count == (unsigned int)(end_offs & (PAGE_CACHE_SIZE - 1)) + 1) { + if (count != PAGE_CACHE_SIZE) memclear_highpage_flush(page, count, PAGE_CACHE_SIZE - count); - SetPageUptodate(page); - } + SetPageUptodate(page); } /* @@ -330,9 +316,7 @@ int nfs_writepage(struct page *page, str { struct nfs_open_context *ctx; struct inode *inode = page->mapping->host; - unsigned long end_index; - unsigned offset = PAGE_CACHE_SIZE; - loff_t i_size = i_size_read(inode); + unsigned offset; int inode_referenced = 0; int priority = wb_priority(wbc); int err; @@ -350,22 +334,15 @@ int nfs_writepage(struct page *page, str */ if (igrab(inode) != 0) inode_referenced = 1; - end_index = i_size >> PAGE_CACHE_SHIFT; /* Ensure we've flushed out any previous writes */ nfs_wb_page_priority(inode, page, priority); - /* easy case */ - if (page->index < end_index) - goto do_it; - /* things got complicated... */ - offset = i_size & (PAGE_CACHE_SIZE-1); - - /* OK, are we completely out? */ - err = 0; /* potential race with truncate - ignore */ - if (page->index >= end_index+1 || !offset) + err = 0; + offset = nfs_page_length(page); + if (!offset) goto out; -do_it: + ctx = nfs_find_open_context(inode, NULL, FMODE_WRITE); if (ctx == NULL) { err = -EBADF; @@ -826,20 +803,8 @@ int nfs_updatepage(struct file *file, st * fragmenting write requests. */ if (PageUptodate(page) && inode->i_flock == NULL && !(file->f_mode & O_SYNC)) { - loff_t end_offs = i_size_read(inode) - 1; - unsigned long end_index = end_offs >> PAGE_CACHE_SHIFT; - - count += offset; + count = max(count + offset, nfs_page_length(page)); offset = 0; - if (unlikely(end_offs < 0)) { - /* Do nothing */ - } else if (page->index == end_index) { - unsigned int pglen; - pglen = (unsigned int)(end_offs & (PAGE_CACHE_SIZE-1)) + 1; - if (count < pglen) - count = pglen; - } else if (page->index < end_index) - count = PAGE_CACHE_SIZE; } /*