[PATCH 3/17] afs: convert afs_dir_get_page to read_kmap_page

Nate Diller
2007-04-12T02:51:41Z

Replace afs_dir_get_page() and afs_dir_put_page() using the new
read_kmap_page() and put_kmapped_page() calls, and eliminate unnecessary
PageError checks. Also, change the afs_dir_check_page() call to return
the page's error status, and update the call site accordingly.

Signed-off-by: Nate Diller <nate.diller@gmail.com>

---

diff -urpN -X dontdiff linux-2.6.21-rc5-mm4/fs/afs/dir.c linux-2.6.21-rc5-mm4-test/fs/afs/dir.c
--- linux-2.6.21-rc5-mm4/fs/afs/dir.c 2007-04-06 12:27:03.000000000 -0700
+++ linux-2.6.21-rc5-mm4-test/fs/afs/dir.c 2007-04-06 14:30:22.000000000 -0700
@@ -115,12 +115,15 @@ struct afs_dir_lookup_cookie {
/*
* check that a directory page is valid
*/
-static inline void afs_dir_check_page(struct inode *dir, struct page *page)
+static inline int afs_dir_check_page(struct inode *dir, struct page *page)
{
struct afs_dir_page *dbuf;
loff_t latter;
int tmp, qty;

+ if (likely(PageChecked(page)))
+ return PageError(page);
+
#if 0
/* check the page count */
qty = desc.size / sizeof(dbuf->blocks[0]);
@@ -154,52 +157,16 @@ static inline void afs_dir_check_page(st
}

SetPageChecked(page);
- return;
+ return 0;

error:
SetPageChecked(page);
SetPageError(page);
-
+ return 1;
} /* end afs_dir_check_page() */

/*****************************************************************************/
/*
- * discard a page cached in the pagecache
- */
-static inline void afs_dir_put_page(struct page *page)
-{
- kunmap(page);
- page_cache_release(page);
-
-} /* end afs_dir_put_page() */
-
-/*****************************************************************************/
-/*
- * get a page into the pagecache
- */
-static struct page *afs_dir_get_page(struct inode *dir, unsigned long index)
-{
- struct page *page;
-
- _enter("{%lu},%lu", dir->i_ino, index);
-
- page = read_mapping_page(dir->i_mapping, index, NULL);
- if (!IS_ERR(page)) {
- kmap(page);
- if (!PageChecked(page))
- afs_dir_check_page(dir, page);
- if (PageError(page))
- goto fail;
- }
- return page;
-
- fail:
- afs_dir_put_page(page);
- return ERR_PTR(-EIO);
-} /* end afs_dir_get_page() */
-
-/*****************************************************************************/
-/*
* open an AFS directory file
*/
static int afs_dir_open(struct inode *inode, struct file *file)
@@ -344,11 +311,16 @@ static int afs_dir_iterate(struct inode
blkoff = *fpos & ~(sizeof(union afs_dir_block) - 1);

/* fetch the appropriate page from the directory */
- page = afs_dir_get_page(dir, blkoff / PAGE_SIZE);
+ page = read_kmap_page(dir->i_mapping, blkoff / PAGE_SIZE);
if (IS_ERR(page)) {
ret = PTR_ERR(page);
break;
}
+ if (afs_check_page(dir, page)) {
+ err = -EIO;
+ put_kmapped_page(page);
+ break;
+ }

limit = blkoff & ~(PAGE_SIZE - 1);

@@ -361,7 +333,7 @@ static int afs_dir_iterate(struct inode
ret = afs_dir_iterate_block(fpos, dblock, blkoff,
cookie, filldir);
if (ret != 1) {
- afs_dir_put_page(page);
+ put_kmapped_page(page);
goto out;
}

@@ -369,7 +341,7 @@ static int afs_dir_iterate(struct inode

} while (*fpos < dir->i_size && blkoff < limit);

- afs_dir_put_page(page);
+ put_kmapped_page(page);
ret = 0;
}

diff -urpN -X dontdiff linux-2.6.21-rc6-mm1/fs/afs/mntpt.c linux-2.6.21-rc6-mm1-test/fs/afs/mntpt.c
--- linux-2.6.21-rc6-mm1/fs/afs/mntpt.c 2007-04-09 17:24:03.000000000 -0700
+++ linux-2.6.21-rc6-mm1-test/fs/afs/mntpt.c 2007-04-10 21:22:07.000000000 -0700
@@ -74,11 +74,6 @@ int afs_mntpt_check_symlink(struct afs_v
ret = PTR_ERR(page);
goto out;
}
-
- ret = -EIO;
- if (PageError(page))
- goto out_free;
-
buf = kmap(page);

/* examine the symlink's contents */
@@ -98,7 +93,6 @@ int afs_mntpt_check_symlink(struct afs_v
ret = 0;

kunmap(page);
- out_free:
page_cache_release(page);
out:
_leave(" = %d", ret);
@@ -180,10 +174,6 @@ static struct vfsmount *afs_mntpt_do_aut
goto error;
}

- ret = -EIO;
- if (PageError(page))
- goto error;
-
buf = kmap(page);
memcpy(devname, buf, size);
kunmap(page);