lkml.org 
[lkml]   [2002]   [Oct]   [17]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
Date
From
Subject[PATCH] tmpfs 9/9 Ingo's shmem_populate
Instate Ingo's shmem_populate on top of the previous patches, now using
shmem_getpage(,,,SGP_QUICK) for the nonblocking case (its find_lock_page
may block, but rarely for long). Note install_page will need redefining
if PAGE_CACHE_SIZE departs from PAGE_SIZE; note pgoff to populate must
be in terms of PAGE_SIZE; note page_cache_release if install_page fails.

filemap_populate similarly needs page_cache_release when install_page
fails, but filemap.c not included in this patch since we started out
from 2.5.43 rather than 2.5.43-mm2: whereas patches 1-8 could go
directly to 2.5.43, this 9/9 belongs with Ingo's population work.

--- tmpfs8/mm/shmem.c Thu Oct 17 22:01:59 2002
+++ tmpfs9/mm/shmem.c Thu Oct 17 22:02:09 2002
@@ -53,6 +53,7 @@

/* Flag allocation requirements to shmem_getpage and shmem_swp_alloc */
enum sgp_type {
+ SGP_QUICK, /* don't try more than file page cache lookup */
SGP_READ, /* don't exceed i_size, don't allocate page */
SGP_CACHE, /* don't exceed i_size, may allocate page */
SGP_WRITE, /* may exceed i_size, may allocate page */
@@ -757,6 +758,8 @@
if (filepage && PageUptodate(filepage))
goto done;
error = 0;
+ if (sgp == SGP_QUICK)
+ goto failed;

spin_lock(&info->lock);
shmem_recalc_inode(inode);
@@ -949,6 +952,42 @@
return page;
}

+static int shmem_populate(struct vm_area_struct *vma,
+ unsigned long addr, unsigned long len,
+ unsigned long prot, unsigned long pgoff, int nonblock)
+{
+ struct inode *inode = vma->vm_file->f_dentry->d_inode;
+ struct mm_struct *mm = vma->vm_mm;
+ enum sgp_type sgp = nonblock? SGP_QUICK: SGP_CACHE;
+ unsigned long size;
+
+ size = (inode->i_size + PAGE_SIZE - 1) >> PAGE_SHIFT;
+ if (pgoff >= size || pgoff + (len >> PAGE_SHIFT) > size)
+ return -EINVAL;
+
+ while ((long) len > 0) {
+ struct page *page = NULL;
+ int err;
+ /*
+ * Will need changing if PAGE_CACHE_SIZE != PAGE_SIZE
+ */
+ err = shmem_getpage(inode, pgoff, &page, sgp);
+ if (err)
+ return err;
+ if (page) {
+ err = install_page(mm, vma, addr, page, prot);
+ if (err) {
+ page_cache_release(page);
+ return err;
+ }
+ }
+ len -= PAGE_SIZE;
+ addr += PAGE_SIZE;
+ pgoff++;
+ }
+ return 0;
+}
+
void shmem_lock(struct file *file, int lock)
{
struct inode *inode = file->f_dentry->d_inode;
@@ -1829,6 +1868,7 @@

static struct vm_operations_struct shmem_vm_ops = {
.nopage = shmem_nopage,
+ .populate = shmem_populate,
};

static struct super_block *shmem_get_sb(struct file_system_type *fs_type,
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/

\
 
 \ /
  Last update: 2005-03-22 13:30    [from the cache]
©2003-2011 Jasper Spaans. Advertise on this site