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authorAl Viro <viro@zeniv.linux.org.uk>2017-06-14 23:32:19 -0400
committerAl Viro <viro@zeniv.linux.org.uk>2017-06-14 23:32:19 -0400
commit267309f394bf3cd8db001992890b1fa52b97974e (patch)
tree1d9917f5ac2b5a6c68607074aaab6bcd1c78452e
parentc596961d1b4ccc6f15754fe5a49c37ac6da57145 (diff)
ufs_get_locked_page(): make sure we have buffer_heads
callers rely upon that, but find_lock_page() racing with attempt of page eviction by memory pressure might have left us with * try_to_free_buffers() successfully done * __remove_mapping() failed, leaving the page in our mapping * find_lock_page() returning an uptodate page with no buffer_heads attached. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
-rw-r--r--fs/ufs/util.c17
1 files changed, 8 insertions, 9 deletions
diff --git a/fs/ufs/util.c b/fs/ufs/util.c
index f41ad0a6106f..02497a492eb2 100644
--- a/fs/ufs/util.c
+++ b/fs/ufs/util.c
@@ -243,9 +243,8 @@ ufs_set_inode_dev(struct super_block *sb, struct ufs_inode_info *ufsi, dev_t dev
struct page *ufs_get_locked_page(struct address_space *mapping,
pgoff_t index)
{
- struct page *page;
-
- page = find_lock_page(mapping, index);
+ struct inode *inode = mapping->host;
+ struct page *page = find_lock_page(mapping, index);
if (!page) {
page = read_mapping_page(mapping, index, NULL);
@@ -253,7 +252,7 @@ struct page *ufs_get_locked_page(struct address_space *mapping,
printk(KERN_ERR "ufs_change_blocknr: "
"read_mapping_page error: ino %lu, index: %lu\n",
mapping->host->i_ino, index);
- goto out;
+ return page;
}
lock_page(page);
@@ -262,8 +261,7 @@ struct page *ufs_get_locked_page(struct address_space *mapping,
/* Truncate got there first */
unlock_page(page);
put_page(page);
- page = NULL;
- goto out;
+ return NULL;
}
if (!PageUptodate(page) || PageError(page)) {
@@ -272,11 +270,12 @@ struct page *ufs_get_locked_page(struct address_space *mapping,
printk(KERN_ERR "ufs_change_blocknr: "
"can not read page: ino %lu, index: %lu\n",
- mapping->host->i_ino, index);
+ inode->i_ino, index);
- page = ERR_PTR(-EIO);
+ return ERR_PTR(-EIO);
}
}
-out:
+ if (!page_has_buffers(page))
+ create_empty_buffers(page, 1 << inode->i_blkbits, 0);
return page;
}