This patch adds FS_IOC_FSSETXATTR/FS_IOC_FSGETXATTR ioctl interface support for btrfs. Extended file attributes are 32 bit values (FS_XFLAGS_SYNC, FS_XFLAG_IMMUTABLE, etc) which have one-to-one mapping to the flag values that can be stored in inode->i_flags (i.e. S_SYNC, S_IMMUTABLE, etc). The flags can be set/unset to enable/disable file attributes. These attributes are listed/modified by lsattr/chattr.
Signed-off-by: Chandan Jay Sharma <[email protected]> --- fs/btrfs/ioctl.c | 148 +++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 148 insertions(+) diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c index dabfc7a..5d8486b 100644 --- a/fs/btrfs/ioctl.c +++ b/fs/btrfs/ioctl.c @@ -132,6 +132,25 @@ static unsigned int btrfs_flags_to_ioctl(unsigned int flags) return iflags; } +/* Transfer ioctl flags to btrfs internal flags */ +static unsigned int btrfs_ioctl_to_flags(unsigned int iflags) +{ + unsigned int flags = 0; + + if (iflags & FS_SYNC_FL) + flags |= BTRFS_INODE_SYNC; + if (iflags & FS_IMMUTABLE_FL) + flags |= BTRFS_INODE_IMMUTABLE; + if (iflags & FS_APPEND_FL) + flags |= BTRFS_INODE_APPEND; + if (iflags & FS_NODUMP_FL) + flags |= BTRFS_INODE_NODUMP; + if (iflags & FS_NOATIME_FL) + flags |= BTRFS_INODE_NOATIME; + + return flags; +} + /* * Update inode->i_flags based on the btrfs internal flags. */ @@ -157,6 +176,75 @@ void btrfs_update_iflags(struct inode *inode) } /* + * Propagate flags from i_flags to BTRFS_I(inode)->flags + */ +void btrfs_get_inode_flags(struct btrfs_inode *ip) +{ + unsigned int vfs_fl; + unsigned long old_fl, new_fl; + + do { + vfs_fl = ip->vfs_inode.i_flags; + old_fl = ip->flags; + new_fl = old_fl & ~(BTRFS_INODE_SYNC|BTRFS_INODE_APPEND| + BTRFS_INODE_IMMUTABLE|BTRFS_INODE_NOATIME| + BTRFS_INODE_DIRSYNC); + if (vfs_fl & S_SYNC) + new_fl |= BTRFS_INODE_SYNC; + if (vfs_fl & S_APPEND) + new_fl |= BTRFS_INODE_APPEND; + if (vfs_fl & S_IMMUTABLE) + new_fl |= BTRFS_INODE_IMMUTABLE; + if (vfs_fl & S_NOATIME) + new_fl |= BTRFS_INODE_NOATIME; + if (vfs_fl & S_DIRSYNC) + new_fl |= BTRFS_INODE_DIRSYNC; + } while (cmpxchg(&ip->flags, old_fl, new_fl) != old_fl); +} + +/* + * Translate btrfs internal flags BTRFS_I(inode)->flags to xflags. + */ +static inline unsigned int btrfs_flags_to_xflags(unsigned int flags) +{ + unsigned int xflags = 0; + + if (flags & BTRFS_INODE_SYNC) + xflags |= FS_XFLAG_SYNC; + if (flags & BTRFS_INODE_IMMUTABLE) + xflags |= FS_XFLAG_IMMUTABLE; + if (flags & BTRFS_INODE_APPEND) + xflags |= FS_XFLAG_APPEND; + if (flags & BTRFS_INODE_NODUMP) + xflags |= FS_XFLAG_NODUMP; + if (flags & BTRFS_INODE_NOATIME) + xflags |= FS_XFLAG_NOATIME; + + return xflags; +} + +/* + * Transfer xflags flags to ioctl flags. + */ +static inline unsigned int btrfs_xflags_to_ioctl(unsigned int xflags) +{ + unsigned int flags = 0; + + if (xflags & FS_XFLAG_SYNC) + flags |= FS_SYNC_FL; + if (xflags & FS_XFLAG_IMMUTABLE) + flags |= FS_IMMUTABLE_FL; + if (xflags & FS_XFLAG_APPEND) + flags |= FS_APPEND_FL; + if (xflags & FS_XFLAG_NODUMP) + flags |= FS_NODUMP_FL; + if (xflags & FS_XFLAG_NOATIME) + flags |= FS_NOATIME_FL; + + return flags; +} + +/* * Inherit flags from the parent inode. * * Currently only the compression flags and the cow flags are inherited. @@ -5504,6 +5592,62 @@ static int btrfs_ioctl_set_features(struct file *file, void __user *arg) return ret; } +static int btrfs_ioctl_fsgetxattr(struct file *file, void __user *arg) +{ + struct fsxattr fa; + struct btrfs_inode *ip = BTRFS_I(file_inode(file)); + + memset(&fa, 0, sizeof(struct fsxattr)); + btrfs_get_inode_flags(ip); + fa.fsx_xflags = btrfs_flags_to_xflags(ip->flags); + + if (copy_to_user((struct fsxattr __user *)arg, + &fa, sizeof(fa))) + return -EFAULT; + + return 0; +} + +static int btrfs_ioctl_fssetxattr(struct file *file, void __user *arg) +{ + struct inode *inode = file_inode(file); + struct btrfs_inode *ip = BTRFS_I(inode); + struct btrfs_root *root = ip->root; + struct fsxattr fa; + unsigned int flags; + int err; + + /* Make sure caller has proper permission */ + if (!inode_owner_or_capable(inode)) + return -EPERM; + + if (btrfs_root_readonly(root)) + return -EROFS; + + memset(&fa, 0, sizeof(struct fsxattr)); + if (copy_from_user(&fa, (struct fsxattr __user *)arg, + sizeof(fa))) + return -EFAULT; + + flags = btrfs_xflags_to_ioctl(fa.fsx_xflags); + + if (btrfs_mask_flags(inode->i_mode, flags) != flags) + return -EOPNOTSUPP; + + err = mnt_want_write_file(file); + if (err) + return err; + + inode_lock(inode); + ip->flags = (ip->flags | btrfs_ioctl_to_flags(flags)); + btrfs_update_iflags(inode); + inode_unlock(inode); + + mnt_drop_write_file(file); + + return 0; +} + long btrfs_ioctl(struct file *file, unsigned int cmd, unsigned long arg) { @@ -5638,6 +5782,10 @@ long btrfs_ioctl(struct file *file, unsigned int return btrfs_ioctl_get_features(file, argp); case BTRFS_IOC_SET_FEATURES: return btrfs_ioctl_set_features(file, argp); + case FS_IOC_FSGETXATTR: + return btrfs_ioctl_fsgetxattr(file, argp); + case FS_IOC_FSSETXATTR: + return btrfs_ioctl_fssetxattr(file, argp); } return -ENOTTY; -- 2.9.3 -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
