| Message ID | 20230718-ctime-v1-1-24e2f96dcdf3@kernel.org |
|---|---|
| State | Handled Elsewhere |
| Headers | show |
| Series | ext4: fix the time handling macros when ext4 is using small inodes | expand |
On Tue 18-07-23 13:31:59, Jeff Layton wrote: > If ext4 is using small on-disk inodes, then it may not be able to store > fine grained timestamps. It also can't store the i_crtime at all in that > case since that fully lives in the extended part of the inode. > > 979492850abd got the EXT4_EINODE_{GET,SET}_XTIME macros wrong, and would > still store the tv_sec field of the i_crtime into the raw_inode, even > when they were small, corrupting adjacent memory. > > This fixes those macros to skip setting anything in the raw_inode if the > tv_sec field doesn't fit, and to properly return a {0,0} timestamp when > the raw_inode doesn't support it. > > Cc: Jan Kara <jack@suse.cz> > Fixes: 979492850abd ("ext4: convert to ctime accessor functions") > Reported-by: Hugh Dickins <hughd@google.com> > Signed-off-by: Jeff Layton <jlayton@kernel.org> I've seen Christian has already folded this fixup so I just want to say: Thanks for fixing this up while I was away! Honza
diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h index 2af347669db7..1e2259d9967d 100644 --- a/fs/ext4/ext4.h +++ b/fs/ext4/ext4.h @@ -900,8 +900,10 @@ do { \ #define EXT4_INODE_SET_CTIME(inode, raw_inode) \ EXT4_INODE_SET_XTIME_VAL(i_ctime, inode, raw_inode, inode_get_ctime(inode)) -#define EXT4_EINODE_SET_XTIME(xtime, einode, raw_inode) \ - EXT4_INODE_SET_XTIME_VAL(xtime, &((einode)->vfs_inode), raw_inode, (einode)->xtime) +#define EXT4_EINODE_SET_XTIME(xtime, einode, raw_inode) \ + if (EXT4_FITS_IN_INODE(raw_inode, einode, xtime)) \ + EXT4_INODE_SET_XTIME_VAL(xtime, &((einode)->vfs_inode), \ + raw_inode, (einode)->xtime) #define EXT4_INODE_GET_XTIME_VAL(xtime, inode, raw_inode) \ (EXT4_FITS_IN_INODE(raw_inode, EXT4_I(inode), xtime ## _extra) ? \ @@ -922,9 +924,14 @@ do { \ EXT4_INODE_GET_XTIME_VAL(i_ctime, inode, raw_inode)); \ } while (0) -#define EXT4_EINODE_GET_XTIME(xtime, einode, raw_inode) \ -do { \ - (einode)->xtime = EXT4_INODE_GET_XTIME_VAL(xtime, &(einode->vfs_inode), raw_inode); \ +#define EXT4_EINODE_GET_XTIME(xtime, einode, raw_inode) \ +do { \ + if (EXT4_FITS_IN_INODE(raw_inode, einode, xtime)) \ + (einode)->xtime = \ + EXT4_INODE_GET_XTIME_VAL(xtime, &(einode->vfs_inode), \ + raw_inode); \ + else \ + (einode)->xtime = (struct timespec64){0, 0}; \ } while (0) #define i_disk_version osd1.linux1.l_i_version
If ext4 is using small on-disk inodes, then it may not be able to store fine grained timestamps. It also can't store the i_crtime at all in that case since that fully lives in the extended part of the inode. 979492850abd got the EXT4_EINODE_{GET,SET}_XTIME macros wrong, and would still store the tv_sec field of the i_crtime into the raw_inode, even when they were small, corrupting adjacent memory. This fixes those macros to skip setting anything in the raw_inode if the tv_sec field doesn't fit, and to properly return a {0,0} timestamp when the raw_inode doesn't support it. Cc: Jan Kara <jack@suse.cz> Fixes: 979492850abd ("ext4: convert to ctime accessor functions") Reported-by: Hugh Dickins <hughd@google.com> Signed-off-by: Jeff Layton <jlayton@kernel.org> --- fs/ext4/ext4.h | 17 ++++++++++++----- 1 file changed, 12 insertions(+), 5 deletions(-) --- base-commit: c62e19541f8bb39f1f340247f651afe4532243df change-id: 20230718-ctime-f140dae8789d Best regards,