Rewrite xfile_obj_store to use xfile_get_page and xfile_put_page to
access the data in the shmem page cache instead of abusing the
shmem write_begin and write_end aops.
Signed-off-by: Christoph Hellwig <hch@xxxxxx>
---
fs/xfs/scrub/xfile.c | 66 ++++++++------------------------------------
1 file changed, 11 insertions(+), 55 deletions(-)
diff --git a/fs/xfs/scrub/xfile.c b/fs/xfs/scrub/xfile.c
index 3ed7fb82a4497b..987b03df241b02 100644
--- a/fs/xfs/scrub/xfile.c
+++ b/fs/xfs/scrub/xfile.c
@@ -182,74 +182,30 @@ xfile_obj_store(
size_t count,
loff_t pos)
{
- struct inode *inode = file_inode(xf->file);
- struct address_space *mapping = inode->i_mapping;
- const struct address_space_operations *aops = mapping->a_ops;
- struct page *page = NULL;
- unsigned int pflags;
- int error = 0;
-
if (count > MAX_RW_COUNT)
return -ENOMEM;
- if (inode->i_sb->s_maxbytes - pos < count)
+ if (file_inode(xf->file)->i_sb->s_maxbytes - pos < count)
return -ENOMEM;
trace_xfile_obj_store(xf, pos, count);
- pflags = memalloc_nofs_save();
while (count > 0) {
- void *fsdata = NULL;
- void *p, *kaddr;
+ struct page *page;
unsigned int len;
- int ret;
len = min_t(ssize_t, count, PAGE_SIZE - offset_in_page(pos));
+ page = xfile_get_page(xf, pos, len, XFILE_ALLOC);
+ if (IS_ERR(page))
+ return -ENOMEM;
+ memcpy(page_address(page) + offset_in_page(pos), buf, len);
+ xfile_put_page(xf, page);
- /*
- * We call write_begin directly here to avoid all the freezer
- * protection lock-taking that happens in the normal path.
- * shmem doesn't support fs freeze, but lockdep doesn't know
- * that and will trip over that.
- */
- error = aops->write_begin(NULL, mapping, pos, len, &page,
- &fsdata);
- if (error) {
- error = -ENOMEM;
- break;
- }
-
- /*
- * xfile pages must never be mapped into userspace, so we skip
- * the dcache flush. If the page is not uptodate, zero it
- * before writing data.
- */
- kaddr = page_address(page);
- if (!PageUptodate(page)) {
- memset(kaddr, 0, PAGE_SIZE);
- SetPageUptodate(page);
- }
- p = kaddr + offset_in_page(pos);
- memcpy(p, buf, len);
-
- ret = aops->write_end(NULL, mapping, pos, len, len, page,
- fsdata);
- if (ret < 0) {
- error = -ENOMEM;
- break;
- }
-
- if (ret != len) {
- error = -ENOMEM;
- break;
- }
-
- count -= ret;
- pos += ret;
- buf += ret;
+ count -= len;
+ pos += len;
+ buf += len;
}
- memalloc_nofs_restore(pflags);
- return error;
+ return 0;
}
/* Find the next written area in the xfile data for a given offset. */
--
2.39.2
