The ramfs accounting is broken for shared mmaps. It simply does not
recognize the pages allocated by writing into a shared mapping but
takes them into account when freed.
The attached patch should fix that.
Greetings
Christoph
--- 4-ac9/fs/ramfs/inode.c Thu May 17 16:51:57 2001
+++ u4ac9/fs/ramfs/inode.c Thu May 17 14:47:48 2001
@@ -163,9 +163,6 @@
struct ramfs_sb_info *rsb = RAMFS_SB(inode->i_sb);
int ret = 1;
- if (PageDirty(page)) /* It's already been allocated */
- return 1;
-
lock_rsb(rsb);
if ( (rsb->free_pages > 0) &&
@@ -185,8 +182,7 @@
{
struct ramfs_sb_info *rsb = RAMFS_SB(inode->i_sb);
- if (! PageDirty(page)) /* The page was never allocated
- this can happen if it was only read */
+ if (! Page_Uptodate(page))
return;
lock_rsb(rsb);
@@ -241,6 +237,8 @@
static int ramfs_readpage(struct file *file, struct page * page)
{
if (!Page_Uptodate(page)) {
+ if (!ramfs_alloc_page(file->f_dentry->d_inode, page))
+ return -ENOSPC;
memset(kmap(page), 0, PAGE_CACHE_SIZE);
kunmap(page);
flush_dcache_page(page);
@@ -266,11 +264,12 @@
struct inode *inode = (struct inode *)page->mapping->host;
void *addr;
- if (! ramfs_alloc_page(inode, page))
- return -ENOSPC;
-
addr = (void *) kmap(page);
if (!Page_Uptodate(page)) {
+ if (! ramfs_alloc_page(inode, page)) {
+ kunmap(page);
+ return -ENOSPC;
+ }
memset(addr, 0, PAGE_CACHE_SIZE);
flush_dcache_page(page);
SetPageUptodate(page);
-
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