f2fs: restrict setting up inode.i_advise

In order to give advise to f2fs to recognize hot/cold file, it is possible
that we can set specific bit in inode.i_advise through setxattr(), but
there are several bits which are used internally, such as encrypt_bit,
keep_size_bit, they should never be changed through setxattr().

So that this patch 1) adds FADVISE_MODIFIABLE_BITS to filter modifiable
bits user given, 2) supports to clear {hot,cold}_file bits.

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
This commit is contained in:
Chao Yu 2018-07-19 23:57:54 +08:00 committed by Jaegeuk Kim
parent e6b0b159cf
commit 797c1cb56b
2 changed files with 13 additions and 1 deletions

View File

@ -604,6 +604,8 @@ enum {
#define FADVISE_HOT_BIT 0x20
#define FADVISE_VERITY_BIT 0x40 /* reserved */
#define FADVISE_MODIFIABLE_BITS (FADVISE_COLD_BIT | FADVISE_HOT_BIT)
#define file_is_cold(inode) is_file(inode, FADVISE_COLD_BIT)
#define file_wrong_pino(inode) is_file(inode, FADVISE_LOST_PINO_BIT)
#define file_set_cold(inode) set_file(inode, FADVISE_COLD_BIT)

View File

@ -94,12 +94,22 @@ static int f2fs_xattr_advise_set(const struct xattr_handler *handler,
const char *name, const void *value,
size_t size, int flags)
{
unsigned char old_advise = F2FS_I(inode)->i_advise;
unsigned char new_advise;
if (!inode_owner_or_capable(inode))
return -EPERM;
if (value == NULL)
return -EINVAL;
F2FS_I(inode)->i_advise |= *(char *)value;
new_advise = *(char *)value;
if (new_advise & ~FADVISE_MODIFIABLE_BITS)
return -EINVAL;
new_advise = new_advise & FADVISE_MODIFIABLE_BITS;
new_advise |= old_advise & ~FADVISE_MODIFIABLE_BITS;
F2FS_I(inode)->i_advise = new_advise;
f2fs_mark_inode_dirty_sync(inode, true);
return 0;
}