X-Git-Url: https://git.openpandora.org/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=mm%2Ffilemap.c;h=b9a60c43b61a4649f19a418584af345088e74daf;hb=b83a8e64fd1aecf021111d22c062c97a3241d0c4;hp=9c7334bafda8da5150f4a9f0a7556bda113b8a19;hpb=4854c7b27f0975a2b629f35ea3996d2968eb7c4f;p=pandora-kernel.git

diff --git a/mm/filemap.c b/mm/filemap.c
index 9c7334bafda8..b9a60c43b61a 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -9,7 +9,6 @@
  * most "normal" filesystems (but you don't /have/ to use this:
  * the NFS filesystem used to do this differently, for example)
  */
-#include <linux/config.h>
 #include <linux/module.h>
 #include <linux/slab.h>
 #include <linux/compiler.h>
@@ -120,7 +119,7 @@ void __remove_from_page_cache(struct page *page)
 	radix_tree_delete(&mapping->page_tree, page->index);
 	page->mapping = NULL;
 	mapping->nrpages--;
-	pagecache_acct(-1);
+	__dec_zone_page_state(page, NR_FILE_PAGES);
 }
 
 void remove_from_page_cache(struct page *page)
@@ -449,7 +448,7 @@ int add_to_page_cache(struct page *page, struct address_space *mapping,
 			page->mapping = mapping;
 			page->index = offset;
 			mapping->nrpages++;
-			pagecache_acct(1);
+			__inc_zone_page_state(page, NR_FILE_PAGES);
 		}
 		write_unlock_irq(&mapping->tree_lock);
 		radix_tree_preload_end();
@@ -850,8 +849,6 @@ static void shrink_readahead_size_eio(struct file *filp,
 		return;
 
 	ra->ra_pages /= 4;
-	printk(KERN_WARNING "Reducing readahead size to %luK\n",
-			ra->ra_pages << (PAGE_CACHE_SHIFT - 10));
 }
 
 /**
@@ -1416,7 +1413,7 @@ retry_find:
 		 */
 		if (!did_readaround) {
 			majmin = VM_FAULT_MAJOR;
-			inc_page_state(pgmajfault);
+			count_vm_event(PGMAJFAULT);
 		}
 		did_readaround = 1;
 		ra_pages = max_sane_readahead(file->f_ra.ra_pages);
@@ -1487,7 +1484,7 @@ no_cached_page:
 page_not_uptodate:
 	if (!did_readaround) {
 		majmin = VM_FAULT_MAJOR;
-		inc_page_state(pgmajfault);
+		count_vm_event(PGMAJFAULT);
 	}
 	lock_page(page);
 
@@ -2069,7 +2066,7 @@ generic_file_buffered_write(struct kiocb *iocb, const struct iovec *iov,
 {
 	struct file *file = iocb->ki_filp;
 	struct address_space * mapping = file->f_mapping;
-	struct address_space_operations *a_ops = mapping->a_ops;
+	const struct address_space_operations *a_ops = mapping->a_ops;
 	struct inode 	*inode = mapping->host;
 	long		status = 0;
 	struct page	*page;
@@ -2095,14 +2092,21 @@ generic_file_buffered_write(struct kiocb *iocb, const struct iovec *iov,
 	do {
 		unsigned long index;
 		unsigned long offset;
-		unsigned long maxlen;
 		size_t copied;
 
 		offset = (pos & (PAGE_CACHE_SIZE -1)); /* Within page */
 		index = pos >> PAGE_CACHE_SHIFT;
 		bytes = PAGE_CACHE_SIZE - offset;
-		if (bytes > count)
-			bytes = count;
+
+		/* Limit the size of the copy to the caller's write size */
+		bytes = min(bytes, count);
+
+		/*
+		 * Limit the size of the copy to that of the current segment,
+		 * because fault_in_pages_readable() doesn't know how to walk
+		 * segments.
+		 */
+		bytes = min(bytes, cur_iov->iov_len - iov_base);
 
 		/*
 		 * Bring in the user page that we will copy from _first_.
@@ -2110,10 +2114,7 @@ generic_file_buffered_write(struct kiocb *iocb, const struct iovec *iov,
 		 * same page as we're writing to, without it being marked
 		 * up-to-date.
 		 */
-		maxlen = cur_iov->iov_len - iov_base;
-		if (maxlen > bytes)
-			maxlen = bytes;
-		fault_in_pages_readable(buf, maxlen);
+		fault_in_pages_readable(buf, bytes);
 
 		page = __grab_cache_page(mapping,index,&cached_page,&lru_pvec);
 		if (!page) {
@@ -2121,6 +2122,12 @@ generic_file_buffered_write(struct kiocb *iocb, const struct iovec *iov,
 			break;
 		}
 
+		if (unlikely(bytes == 0)) {
+			status = 0;
+			copied = 0;
+			goto zero_length_segment;
+		}
+
 		status = a_ops->prepare_write(file, page, offset, offset+bytes);
 		if (unlikely(status)) {
 			loff_t isize = i_size_read(inode);
@@ -2150,7 +2157,8 @@ generic_file_buffered_write(struct kiocb *iocb, const struct iovec *iov,
 			page_cache_release(page);
 			continue;
 		}
-		if (likely(copied > 0)) {
+zero_length_segment:
+		if (likely(copied >= 0)) {
 			if (!status)
 				status = copied;
 
@@ -2215,7 +2223,7 @@ __generic_file_aio_write_nolock(struct kiocb *iocb, const struct iovec *iov,
 				unsigned long nr_segs, loff_t *ppos)
 {
 	struct file *file = iocb->ki_filp;
-	struct address_space * mapping = file->f_mapping;
+	const struct address_space * mapping = file->f_mapping;
 	size_t ocount;		/* original count */
 	size_t count;		/* after file limit checks */
 	struct inode 	*inode = mapping->host;