From 267309f394bf3cd8db001992890b1fa52b97974e Mon Sep 17 00:00:00 2001 From: Al Viro Date: Wed, 14 Jun 2017 23:32:19 -0400 Subject: [PATCH] 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 --- fs/ufs/util.c | 17 ++++++++--------- 1 file 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; }