Commit 6fe6900e authored by Nick Piggin's avatar Nick Piggin Committed by Linus Torvalds
Browse files

mm: make read_cache_page synchronous



Ensure pages are uptodate after returning from read_cache_page, which allows
us to cut out most of the filesystem-internal PageUptodate calls.

I didn't have a great look down the call chains, but this appears to fixes 7
possible use-before uptodate in hfs, 2 in hfsplus, 1 in jfs, a few in
ecryptfs, 1 in jffs2, and a possible cleared data overwritten with readpage in
block2mtd.  All depending on whether the filler is async and/or can return
with a !uptodate page.
Signed-off-by: default avatarNick Piggin <npiggin@suse.de>
Cc: Hugh Dickins <hugh@veritas.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 714b8171
......@@ -40,13 +40,11 @@ struct block2mtd_dev {
static LIST_HEAD(blkmtd_device_list);
static struct page* page_read(struct address_space *mapping, int index)
static struct page *page_read(struct address_space *mapping, int index)
{
filler_t *filler = (filler_t*)mapping->a_ops->readpage;
return read_cache_page(mapping, index, filler, NULL);
return read_mapping_page(mapping, index, NULL);
}
/* erase a specified part of the device */
static int _block2mtd_erase(struct block2mtd_dev *dev, loff_t to, size_t len)
{
......
......@@ -194,10 +194,7 @@ static struct page *afs_dir_get_page(struct inode *dir, unsigned long index,
page = read_mapping_page(dir->i_mapping, index, &file);
if (!IS_ERR(page)) {
wait_on_page_locked(page);
kmap(page);
if (!PageUptodate(page))
goto fail;
if (!PageChecked(page))
afs_dir_check_page(dir, page);
if (PageError(page))
......
......@@ -68,13 +68,11 @@ int afs_mntpt_check_symlink(struct afs_vnode *vnode, struct key *key)
}
ret = -EIO;
wait_on_page_locked(page);
buf = kmap(page);
if (!PageUptodate(page))
goto out_free;
if (PageError(page))
goto out_free;
buf = kmap(page);
/* examine the symlink's contents */
size = vnode->status.size;
_debug("symlink to %*.*s", (int) size, (int) size, buf);
......@@ -91,8 +89,8 @@ int afs_mntpt_check_symlink(struct afs_vnode *vnode, struct key *key)
ret = 0;
out_free:
kunmap(page);
out_free:
page_cache_release(page);
out:
_leave(" = %d", ret);
......@@ -171,8 +169,7 @@ static struct vfsmount *afs_mntpt_do_automount(struct dentry *mntpt)
}
ret = -EIO;
wait_on_page_locked(page);
if (!PageUptodate(page) || PageError(page))
if (PageError(page))
goto error;
buf = kmap(page);
......
......@@ -180,7 +180,8 @@ static void *cramfs_read(struct super_block *sb, unsigned int offset, unsigned i
struct page *page = NULL;
if (blocknr + i < devsize) {
page = read_mapping_page(mapping, blocknr + i, NULL);
page = read_mapping_page_async(mapping, blocknr + i,
NULL);
/* synchronous error? */
if (IS_ERR(page))
page = NULL;
......
......@@ -46,7 +46,6 @@ struct kmem_cache *ecryptfs_lower_page_cache;
*/
static struct page *ecryptfs_get1page(struct file *file, int index)
{
struct page *page;
struct dentry *dentry;
struct inode *inode;
struct address_space *mapping;
......@@ -54,14 +53,7 @@ static struct page *ecryptfs_get1page(struct file *file, int index)
dentry = file->f_path.dentry;
inode = dentry->d_inode;
mapping = inode->i_mapping;
page = read_cache_page(mapping, index,
(filler_t *)mapping->a_ops->readpage,
(void *)file);
if (IS_ERR(page))
goto out;
wait_on_page_locked(page);
out:
return page;
return read_mapping_page(mapping, index, (void *)file);
}
static
......@@ -233,7 +225,6 @@ int ecryptfs_do_readpage(struct file *file, struct page *page,
ecryptfs_printk(KERN_ERR, "Error reading from page cache\n");
goto out;
}
wait_on_page_locked(lower_page);
page_data = kmap_atomic(page, KM_USER0);
lower_page_data = kmap_atomic(lower_page, KM_USER1);
memcpy(page_data, lower_page_data, PAGE_CACHE_SIZE);
......
......@@ -161,10 +161,7 @@ static struct page * ext2_get_page(struct inode *dir, unsigned long n)
struct address_space *mapping = dir->i_mapping;
struct page *page = read_mapping_page(mapping, n, NULL);
if (!IS_ERR(page)) {
wait_on_page_locked(page);
kmap(page);
if (!PageUptodate(page))
goto fail;
if (!PageChecked(page))
ext2_check_page(page);
if (PageError(page))
......
......@@ -74,10 +74,7 @@ vxfs_get_page(struct address_space *mapping, u_long n)
pp = read_mapping_page(mapping, n, NULL);
if (!IS_ERR(pp)) {
wait_on_page_locked(pp);
kmap(pp);
if (!PageUptodate(pp))
goto fail;
/** if (!PageChecked(pp)) **/
/** vxfs_check_page(pp); **/
if (PageError(pp))
......
......@@ -65,7 +65,6 @@ static struct page * dir_get_page(struct inode *dir, unsigned long n)
struct address_space *mapping = dir->i_mapping;
struct page *page = read_mapping_page(mapping, n, NULL);
if (!IS_ERR(page)) {
wait_on_page_locked(page);
kmap(page);
if (!PageUptodate(page))
goto fail;
......
......@@ -2671,19 +2671,9 @@ static char *page_getlink(struct dentry * dentry, struct page **ppage)
struct address_space *mapping = dentry->d_inode->i_mapping;
page = read_mapping_page(mapping, 0, NULL);
if (IS_ERR(page))
goto sync_fail;
wait_on_page_locked(page);
if (!PageUptodate(page))
goto async_fail;
return (char*)page;
*ppage = page;
return kmap(page);
async_fail:
page_cache_release(page);
return ERR_PTR(-EIO);
sync_fail:
return (char*)page;
}
int page_readlink(struct dentry *dentry, char __user *buffer, int buflen)
......
......@@ -334,8 +334,6 @@ int find_dirent_page(nfs_readdir_descriptor_t *desc)
status = PTR_ERR(page);
goto out;
}
if (!PageUptodate(page))
goto read_error;
/* NOTE: Someone else may have changed the READDIRPLUS flag */
desc->page = page;
......@@ -349,9 +347,6 @@ int find_dirent_page(nfs_readdir_descriptor_t *desc)
out:
dfprintk(DIRCACHE, "NFS: %s: returns %d\n", __FUNCTION__, status);
return status;
read_error:
page_cache_release(page);
return -EIO;
}
/*
......
......@@ -61,15 +61,9 @@ static void *nfs_follow_link(struct dentry *dentry, struct nameidata *nd)
err = page;
goto read_failed;
}
if (!PageUptodate(page)) {
err = ERR_PTR(-EIO);
goto getlink_read_error;
}
nd_set_link(nd, kmap(page));
return page;
getlink_read_error:
page_cache_release(page);
read_failed:
nd_set_link(nd, err);
return NULL;
......
......@@ -89,9 +89,8 @@ static inline struct page *ntfs_map_page(struct address_space *mapping,
struct page *page = read_mapping_page(mapping, index, NULL);
if (!IS_ERR(page)) {
wait_on_page_locked(page);
kmap(page);
if (PageUptodate(page) && !PageError(page))
if (!PageError(page))
return page;
ntfs_unmap_page(page);
return ERR_PTR(-EIO);
......
......@@ -2532,14 +2532,7 @@ int ntfs_attr_set(ntfs_inode *ni, const s64 ofs, const s64 cnt, const u8 val)
page = read_mapping_page(mapping, idx, NULL);
if (IS_ERR(page)) {
ntfs_error(vol->sb, "Failed to read first partial "
"page (sync error, index 0x%lx).", idx);
return PTR_ERR(page);
}
wait_on_page_locked(page);
if (unlikely(!PageUptodate(page))) {
ntfs_error(vol->sb, "Failed to read first partial page "
"(async error, index 0x%lx).", idx);
page_cache_release(page);
"page (error, index 0x%lx).", idx);
return PTR_ERR(page);
}
/*
......@@ -2602,14 +2595,7 @@ int ntfs_attr_set(ntfs_inode *ni, const s64 ofs, const s64 cnt, const u8 val)
page = read_mapping_page(mapping, idx, NULL);
if (IS_ERR(page)) {
ntfs_error(vol->sb, "Failed to read last partial page "
"(sync error, index 0x%lx).", idx);
return PTR_ERR(page);
}
wait_on_page_locked(page);
if (unlikely(!PageUptodate(page))) {
ntfs_error(vol->sb, "Failed to read last partial page "
"(async error, index 0x%lx).", idx);
page_cache_release(page);
"(error, index 0x%lx).", idx);
return PTR_ERR(page);
}
kaddr = kmap_atomic(page, KM_USER0);
......
......@@ -236,8 +236,7 @@ do_non_resident_extend:
err = PTR_ERR(page);
goto init_err_out;
}
wait_on_page_locked(page);
if (unlikely(!PageUptodate(page) || PageError(page))) {
if (unlikely(PageError(page))) {
page_cache_release(page);
err = -EIO;
goto init_err_out;
......
......@@ -2471,7 +2471,6 @@ static s64 get_nr_free_clusters(ntfs_volume *vol)
s64 nr_free = vol->nr_clusters;
u32 *kaddr;
struct address_space *mapping = vol->lcnbmp_ino->i_mapping;
filler_t *readpage = (filler_t*)mapping->a_ops->readpage;
struct page *page;
pgoff_t index, max_index;
......@@ -2494,24 +2493,14 @@ static s64 get_nr_free_clusters(ntfs_volume *vol)
* Read the page from page cache, getting it from backing store
* if necessary, and increment the use count.
*/
page = read_cache_page(mapping, index, (filler_t*)readpage,
NULL);
page = read_mapping_page(mapping, index, NULL);
/* Ignore pages which errored synchronously. */
if (IS_ERR(page)) {
ntfs_debug("Sync read_cache_page() error. Skipping "
ntfs_debug("read_mapping_page() error. Skipping "
"page (index 0x%lx).", index);
nr_free -= PAGE_CACHE_SIZE * 8;
continue;
}
wait_on_page_locked(page);
/* Ignore pages which errored asynchronously. */
if (!PageUptodate(page)) {
ntfs_debug("Async read_cache_page() error. Skipping "
"page (index 0x%lx).", index);
page_cache_release(page);
nr_free -= PAGE_CACHE_SIZE * 8;
continue;
}
kaddr = (u32*)kmap_atomic(page, KM_USER0);
/*
* For each 4 bytes, subtract the number of set bits. If this
......@@ -2562,7 +2551,6 @@ static unsigned long __get_nr_free_mft_records(ntfs_volume *vol,
{
u32 *kaddr;
struct address_space *mapping = vol->mftbmp_ino->i_mapping;
filler_t *readpage = (filler_t*)mapping->a_ops->readpage;
struct page *page;
pgoff_t index;
......@@ -2576,21 +2564,11 @@ static unsigned long __get_nr_free_mft_records(ntfs_volume *vol,
* Read the page from page cache, getting it from backing store
* if necessary, and increment the use count.
*/
page = read_cache_page(mapping, index, (filler_t*)readpage,
NULL);
page = read_mapping_page(mapping, index, NULL);
/* Ignore pages which errored synchronously. */
if (IS_ERR(page)) {
ntfs_debug("Sync read_cache_page() error. Skipping "
"page (index 0x%lx).", index);
nr_free -= PAGE_CACHE_SIZE * 8;
continue;
}
wait_on_page_locked(page);
/* Ignore pages which errored asynchronously. */
if (!PageUptodate(page)) {
ntfs_debug("Async read_cache_page() error. Skipping "
ntfs_debug("read_mapping_page() error. Skipping "
"page (index 0x%lx).", index);
page_cache_release(page);
nr_free -= PAGE_CACHE_SIZE * 8;
continue;
}
......
......@@ -67,16 +67,9 @@ static char *ocfs2_page_getlink(struct dentry * dentry,
page = read_mapping_page(mapping, 0, NULL);
if (IS_ERR(page))
goto sync_fail;
wait_on_page_locked(page);
if (!PageUptodate(page))
goto async_fail;
*ppage = page;
return kmap(page);
async_fail:
page_cache_release(page);
return ERR_PTR(-EIO);
sync_fail:
return (char*)page;
}
......
......@@ -569,9 +569,6 @@ unsigned char *read_dev_sector(struct block_device *bdev, sector_t n, Sector *p)
page = read_mapping_page(mapping, (pgoff_t)(n >> (PAGE_CACHE_SHIFT-9)),
NULL);
if (!IS_ERR(page)) {
wait_on_page_locked(page);
if (!PageUptodate(page))
goto fail;
if (PageError(page))
goto fail;
p->v = page;
......
......@@ -410,11 +410,7 @@ static struct page *reiserfs_get_page(struct inode *dir, unsigned long n)
mapping_set_gfp_mask(mapping, GFP_NOFS);
page = read_mapping_page(mapping, n, NULL);
if (!IS_ERR(page)) {
wait_on_page_locked(page);
kmap(page);
if (!PageUptodate(page))
goto fail;
if (PageError(page))
goto fail;
}
......
......@@ -54,17 +54,9 @@ static struct page * dir_get_page(struct inode *dir, unsigned long n)
{
struct address_space *mapping = dir->i_mapping;
struct page *page = read_mapping_page(mapping, n, NULL);
if (!IS_ERR(page)) {
wait_on_page_locked(page);
if (!IS_ERR(page))
kmap(page);
if (!PageUptodate(page))
goto fail;
}
return page;
fail:
dir_put_page(page);
return ERR_PTR(-EIO);
}
static int sysv_readdir(struct file * filp, void * dirent, filldir_t filldir)
......
......@@ -180,13 +180,9 @@ fail:
static struct page *ufs_get_page(struct inode *dir, unsigned long n)
{
struct address_space *mapping = dir->i_mapping;
struct page *page = read_cache_page(mapping, n,
(filler_t*)mapping->a_ops->readpage, NULL);
struct page *page = read_mapping_page(mapping, n, NULL);
if (!IS_ERR(page)) {
wait_on_page_locked(page);
kmap(page);
if (!PageUptodate(page))
goto fail;
if (!PageChecked(page))
ufs_check_page(page);
if (PageError(page))
......
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