| Message ID | 1403732162-22405-1-git-send-email-fdmanana@gmail.com (mailing list archive) |
|---|---|
| State | Accepted |
| Headers | show |
On Wed, Jun 25, 2014 at 10:36:02PM +0100, Filipe David Borba Manana wrote: > This change is based on the corresponding recent change for ext4: > > ext4: atomically set inode->i_flags in ext4_set_inode_flags() > > That has the following commit message that applies to btrfs as well: > > "Use cmpxchg() to atomically set i_flags instead of clearing out the > S_IMMUTABLE, S_APPEND, etc. flags and then setting them from the > EXT4_IMMUTABLE_FL, EXT4_APPEND_FL flags, since this opens up a race > where an immutable file has the immutable flag cleared for a brief > window of time." > > Replacing EXT4_IMMUTABLE_FL and EXT4_APPEND_FL with BTRFS_INODE_IMMUTABLE > and BTRFS_INODE_APPEND, respectively. > > Signed-off-by: Filipe David Borba Manana <fdmanana@gmail.com> Reviewed-by: David Sterba <dsterba@suse.cz> -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
(2014/07/02 8:56), David Sterba wrote: > On Wed, Jun 25, 2014 at 10:36:02PM +0100, Filipe David Borba Manana wrote: >> This change is based on the corresponding recent change for ext4: >> >> ext4: atomically set inode->i_flags in ext4_set_inode_flags() >> >> That has the following commit message that applies to btrfs as well: >> >> "Use cmpxchg() to atomically set i_flags instead of clearing out the >> S_IMMUTABLE, S_APPEND, etc. flags and then setting them from the >> EXT4_IMMUTABLE_FL, EXT4_APPEND_FL flags, since this opens up a race >> where an immutable file has the immutable flag cleared for a brief >> window of time." >> >> Replacing EXT4_IMMUTABLE_FL and EXT4_APPEND_FL with BTRFS_INODE_IMMUTABLE >> and BTRFS_INODE_APPEND, respectively. >> >> Signed-off-by: Filipe David Borba Manana <fdmanana@gmail.com> > > Reviewed-by: David Sterba <dsterba@suse.cz> Reviewed-by: Satoru Takeuchi <takeuchi_satoru@jp.fujitsu.com> > -- > To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c index 6ea1546..02dc64b 100644 --- a/fs/btrfs/ioctl.c +++ b/fs/btrfs/ioctl.c @@ -136,19 +136,22 @@ static unsigned int btrfs_flags_to_ioctl(unsigned int flags) void btrfs_update_iflags(struct inode *inode) { struct btrfs_inode *ip = BTRFS_I(inode); - - inode->i_flags &= ~(S_SYNC|S_APPEND|S_IMMUTABLE|S_NOATIME|S_DIRSYNC); + unsigned int new_fl = 0; if (ip->flags & BTRFS_INODE_SYNC) - inode->i_flags |= S_SYNC; + new_fl |= S_SYNC; if (ip->flags & BTRFS_INODE_IMMUTABLE) - inode->i_flags |= S_IMMUTABLE; + new_fl |= S_IMMUTABLE; if (ip->flags & BTRFS_INODE_APPEND) - inode->i_flags |= S_APPEND; + new_fl |= S_APPEND; if (ip->flags & BTRFS_INODE_NOATIME) - inode->i_flags |= S_NOATIME; + new_fl |= S_NOATIME; if (ip->flags & BTRFS_INODE_DIRSYNC) - inode->i_flags |= S_DIRSYNC; + new_fl |= S_DIRSYNC; + + set_mask_bits(&inode->i_flags, + S_SYNC | S_APPEND | S_IMMUTABLE | S_NOATIME | S_DIRSYNC, + new_fl); } /*
This change is based on the corresponding recent change for ext4: ext4: atomically set inode->i_flags in ext4_set_inode_flags() That has the following commit message that applies to btrfs as well: "Use cmpxchg() to atomically set i_flags instead of clearing out the S_IMMUTABLE, S_APPEND, etc. flags and then setting them from the EXT4_IMMUTABLE_FL, EXT4_APPEND_FL flags, since this opens up a race where an immutable file has the immutable flag cleared for a brief window of time." Replacing EXT4_IMMUTABLE_FL and EXT4_APPEND_FL with BTRFS_INODE_IMMUTABLE and BTRFS_INODE_APPEND, respectively. Signed-off-by: Filipe David Borba Manana <fdmanana@gmail.com> --- fs/btrfs/ioctl.c | 17 ++++++++++------- 1 file changed, 10 insertions(+), 7 deletions(-)