| Message ID | 20230316142753.6628-1-congmingyi@gmail.com |
|---|---|
| State | New |
| Headers | show |
| Series | [v3] fs: add the tuncate check of exfat | expand |
On Thu, Mar 16, 2023 at 10:27:53PM +0800, MIngyi Cong wrote: > EXFAT will fill zero data in truncated range. > Fix this by adding EXFAT_SUPER_MAGIC check. None of these is correct. We need to find a way to communicate this information without looking at magic numbers.
On Thu, Mar 16, 2023 at 11:15:10PM +0800, Mingyi Cong wrote: > After my analysis, the reason is that the truncate system call of some file > systems will be filled with 0 data. We should add some conditional > judgments to avoid the use of some file systems for truncate. Do you have a > better suggestion for revision? As Ń•aid we need a flag, be that per-file system or per-inode to flag the behavior instead of guessing it from the major number.
diff --git a/fs/ksmbd/smb2pdu.c b/fs/ksmbd/smb2pdu.c index 0685c1c77b9f..3f2e34936b8d 100644 --- a/fs/ksmbd/smb2pdu.c +++ b/fs/ksmbd/smb2pdu.c @@ -5746,7 +5746,8 @@ static int set_end_of_file_info(struct ksmbd_work *work, struct ksmbd_file *fp, * truncate of some filesystem like FAT32 fill zero data in * truncated range. */ - if (inode->i_sb->s_magic != MSDOS_SUPER_MAGIC) { + if (inode->i_sb->s_magic != MSDOS_SUPER_MAGIC || + inode->i_sb->s_magic != EXFAT_SUPER_MAGIC) { ksmbd_debug(SMB, "truncated to newsize %lld\n", newsize); rc = ksmbd_vfs_truncate(work, fp, newsize); if (rc) { diff --git a/include/uapi/linux/magic.h b/include/uapi/linux/magic.h index 6325d1d0e90f..309cb3b5c5c4 100644 --- a/include/uapi/linux/magic.h +++ b/include/uapi/linux/magic.h @@ -46,6 +46,7 @@ #define MSDOS_SUPER_MAGIC 0x4d44 /* MD */ #define EXFAT_SUPER_MAGIC 0x2011BAB0 +#define HFS_SUPER_MAGIC 0x4244 /* "BD": HFS MDB (super block) */ #define NCP_SUPER_MAGIC 0x564c /* Guess, what 0x564c is :-) */ #define NFS_SUPER_MAGIC 0x6969 #define OCFS2_SUPER_MAGIC 0x7461636f
EXFAT will fill zero data in truncated range. Fix this by adding EXFAT_SUPER_MAGIC check. Signed-off-by: MIngyi Cong <congmingyi@gmail.com> --- V1 -> V2: add the truncate check of hfs and remove EXFAT_SUPER_MAGIC in magic.h V2 -> V3: remove the truncate check of hfs and hfsplus fs/ksmbd/smb2pdu.c | 3 ++- include/uapi/linux/magic.h | 1 + 2 files changed, 3 insertions(+), 1 deletion(-)