From 797c1cb56ba58bf42742e9446226345a6216d832 Mon Sep 17 00:00:00 2001 From: Chao Yu Date: Thu, 19 Jul 2018 23:57:54 +0800 Subject: [PATCH] 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 Signed-off-by: Jaegeuk Kim --- fs/f2fs/f2fs.h | 2 ++ fs/f2fs/xattr.c | 12 +++++++++++- 2 files changed, 13 insertions(+), 1 deletion(-) diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h index 5ed85e2..ff8f8d9 100644 --- a/fs/f2fs/f2fs.h +++ b/fs/f2fs/f2fs.h @@ -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) diff --git a/fs/f2fs/xattr.c b/fs/f2fs/xattr.c index 4b34244..77a010e62 100644 --- a/fs/f2fs/xattr.c +++ b/fs/f2fs/xattr.c @@ -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; } -- 2.7.4