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| author | Al Viro <viro@zeniv.linux.org.uk> | 2015-11-17 01:07:57 -0500 |
|---|---|---|
| committer | Al Viro <viro@zeniv.linux.org.uk> | 2015-12-08 22:41:36 -0500 |
| commit | 21fc61c73c3903c4c312d0802da01ec2b323d174 (patch) | |
| tree | a26c29e3fbb766f00b023724e9e5b8b9bba9b879 /fs/befs | |
| parent | aa80deab33a8fb180e718f5e45514db19aade165 (diff) | |
| download | lwn-21fc61c73c3903c4c312d0802da01ec2b323d174.tar.gz lwn-21fc61c73c3903c4c312d0802da01ec2b323d174.zip | |
don't put symlink bodies in pagecache into highmem
kmap() in page_follow_link_light() needed to go - allowing to hold
an arbitrary number of kmaps for long is a great way to deadlocking
the system.
new helper (inode_nohighmem(inode)) needs to be used for pagecache
symlinks inodes; done for all in-tree cases. page_follow_link_light()
instrumented to yell about anything missed.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Diffstat (limited to 'fs/befs')
| -rw-r--r-- | fs/befs/linuxvfs.c | 5 |
1 files changed, 2 insertions, 3 deletions
diff --git a/fs/befs/linuxvfs.c b/fs/befs/linuxvfs.c index 1c8b0dca8b50..25250fa87086 100644 --- a/fs/befs/linuxvfs.c +++ b/fs/befs/linuxvfs.c @@ -397,6 +397,7 @@ static struct inode *befs_iget(struct super_block *sb, unsigned long ino) } else if (S_ISLNK(inode->i_mode)) { if (befs_ino->i_flags & BEFS_LONG_SYMLINK) { inode->i_op = &page_symlink_inode_operations; + inode_nohighmem(inode); inode->i_mapping->a_ops = &befs_symlink_aops; } else { inode->i_link = befs_ino->i_data.symlink; @@ -469,7 +470,7 @@ static int befs_symlink_readpage(struct file *unused, struct page *page) struct befs_inode_info *befs_ino = BEFS_I(inode); befs_data_stream *data = &befs_ino->i_data.ds; befs_off_t len = data->size; - char *link = kmap(page); + char *link = page_address(page); if (len == 0 || len > PAGE_SIZE) { befs_error(sb, "Long symlink with illegal length"); @@ -483,12 +484,10 @@ static int befs_symlink_readpage(struct file *unused, struct page *page) } link[len - 1] = '\0'; SetPageUptodate(page); - kunmap(page); unlock_page(page); return 0; fail: SetPageError(page); - kunmap(page); unlock_page(page); return -EIO; } |