From 6cbff00f4632c8060b06bfc9585805217f11e12e Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Fri, 17 Apr 2009 10:37:41 +0200 Subject: Btrfs: implement FS_IOC_GETFLAGS/SETFLAGS/GETVERSION Add support for the standard attributes set via chattr and read via lsattr. Currently we store the attributes in the flags value in the btrfs inode, but I wonder whether we should split it into two so that we don't have to keep converting between the two formats. Remove the btrfs_clear_flag/btrfs_set_flag/btrfs_test_flag macros as they were confusing the existing code and got in the way of the new additions. Also add the FS_IOC_GETVERSION ioctl for getting i_generation as it's trivial. Signed-off-by: Christoph Hellwig Signed-off-by: Chris Mason --- fs/btrfs/ioctl.c | 171 +++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 171 insertions(+) (limited to 'fs/btrfs/ioctl.c') diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c index 54dfd45cc591..926332a73cde 100644 --- a/fs/btrfs/ioctl.c +++ b/fs/btrfs/ioctl.c @@ -50,7 +50,172 @@ #include "volumes.h" #include "locking.h" +/* Mask out flags that are inappropriate for the given type of inode. */ +static inline __u32 btrfs_mask_flags(umode_t mode, __u32 flags) +{ + if (S_ISDIR(mode)) + return flags; + else if (S_ISREG(mode)) + return flags & ~FS_DIRSYNC_FL; + else + return flags & (FS_NODUMP_FL | FS_NOATIME_FL); +} + +/* + * Export inode flags to the format expected by the FS_IOC_GETFLAGS ioctl. + */ +static unsigned int btrfs_flags_to_ioctl(unsigned int flags) +{ + unsigned int iflags = 0; + + if (flags & BTRFS_INODE_SYNC) + iflags |= FS_SYNC_FL; + if (flags & BTRFS_INODE_IMMUTABLE) + iflags |= FS_IMMUTABLE_FL; + if (flags & BTRFS_INODE_APPEND) + iflags |= FS_APPEND_FL; + if (flags & BTRFS_INODE_NODUMP) + iflags |= FS_NODUMP_FL; + if (flags & BTRFS_INODE_NOATIME) + iflags |= FS_NOATIME_FL; + if (flags & BTRFS_INODE_DIRSYNC) + iflags |= FS_DIRSYNC_FL; + + return iflags; +} + +/* + * Update inode->i_flags based on the btrfs internal 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); + + if (ip->flags & BTRFS_INODE_SYNC) + inode->i_flags |= S_SYNC; + if (ip->flags & BTRFS_INODE_IMMUTABLE) + inode->i_flags |= S_IMMUTABLE; + if (ip->flags & BTRFS_INODE_APPEND) + inode->i_flags |= S_APPEND; + if (ip->flags & BTRFS_INODE_NOATIME) + inode->i_flags |= S_NOATIME; + if (ip->flags & BTRFS_INODE_DIRSYNC) + inode->i_flags |= S_DIRSYNC; +} + +/* + * Inherit flags from the parent inode. + * + * Unlike extN we don't have any flags we don't want to inherit currently. + */ +void btrfs_inherit_iflags(struct inode *inode, struct inode *dir) +{ + unsigned int flags = BTRFS_I(dir)->flags; + + if (S_ISREG(inode->i_mode)) + flags &= ~BTRFS_INODE_DIRSYNC; + else if (!S_ISDIR(inode->i_mode)) + flags &= (BTRFS_INODE_NODUMP | BTRFS_INODE_NOATIME); + + BTRFS_I(inode)->flags = flags; + btrfs_update_iflags(inode); +} + +static int btrfs_ioctl_getflags(struct file *file, void __user *arg) +{ + struct btrfs_inode *ip = BTRFS_I(file->f_path.dentry->d_inode); + unsigned int flags = btrfs_flags_to_ioctl(ip->flags); + + if (copy_to_user(arg, &flags, sizeof(flags))) + return -EFAULT; + return 0; +} + +static int btrfs_ioctl_setflags(struct file *file, void __user *arg) +{ + struct inode *inode = file->f_path.dentry->d_inode; + struct btrfs_inode *ip = BTRFS_I(inode); + struct btrfs_root *root = ip->root; + struct btrfs_trans_handle *trans; + unsigned int flags, oldflags; + int ret; + + if (copy_from_user(&flags, arg, sizeof(flags))) + return -EFAULT; + + if (flags & ~(FS_IMMUTABLE_FL | FS_APPEND_FL | \ + FS_NOATIME_FL | FS_NODUMP_FL | \ + FS_SYNC_FL | FS_DIRSYNC_FL)) + return -EOPNOTSUPP; + if (!is_owner_or_cap(inode)) + return -EACCES; + + mutex_lock(&inode->i_mutex); + + flags = btrfs_mask_flags(inode->i_mode, flags); + oldflags = btrfs_flags_to_ioctl(ip->flags); + if ((flags ^ oldflags) & (FS_APPEND_FL | FS_IMMUTABLE_FL)) { + if (!capable(CAP_LINUX_IMMUTABLE)) { + ret = -EPERM; + goto out_unlock; + } + } + + ret = mnt_want_write(file->f_path.mnt); + if (ret) + goto out_unlock; + + if (flags & FS_SYNC_FL) + ip->flags |= BTRFS_INODE_SYNC; + else + ip->flags &= ~BTRFS_INODE_SYNC; + if (flags & FS_IMMUTABLE_FL) + ip->flags |= BTRFS_INODE_IMMUTABLE; + else + ip->flags &= ~BTRFS_INODE_IMMUTABLE; + if (flags & FS_APPEND_FL) + ip->flags |= BTRFS_INODE_APPEND; + else + ip->flags &= ~BTRFS_INODE_APPEND; + if (flags & FS_NODUMP_FL) + ip->flags |= BTRFS_INODE_NODUMP; + else + ip->flags &= ~BTRFS_INODE_NODUMP; + if (flags & FS_NOATIME_FL) + ip->flags |= BTRFS_INODE_NOATIME; + else + ip->flags &= ~BTRFS_INODE_NOATIME; + if (flags & FS_DIRSYNC_FL) + ip->flags |= BTRFS_INODE_DIRSYNC; + else + ip->flags &= ~BTRFS_INODE_DIRSYNC; + + + trans = btrfs_join_transaction(root, 1); + BUG_ON(!trans); + + ret = btrfs_update_inode(trans, root, inode); + BUG_ON(ret); + + btrfs_update_iflags(inode); + inode->i_ctime = CURRENT_TIME; + btrfs_end_transaction(trans, root); + + mnt_drop_write(file->f_path.mnt); + out_unlock: + mutex_unlock(&inode->i_mutex); + return 0; +} + +static int btrfs_ioctl_getversion(struct file *file, int __user *arg) +{ + struct inode *inode = file->f_path.dentry->d_inode; + + return put_user(inode->i_generation, arg); +} static noinline int create_subvol(struct btrfs_root *root, struct dentry *dentry, @@ -1077,6 +1242,12 @@ long btrfs_ioctl(struct file *file, unsigned int void __user *argp = (void __user *)arg; switch (cmd) { + case FS_IOC_GETFLAGS: + return btrfs_ioctl_getflags(file, argp); + case FS_IOC_SETFLAGS: + return btrfs_ioctl_setflags(file, argp); + case FS_IOC_GETVERSION: + return btrfs_ioctl_getversion(file, argp); case BTRFS_IOC_SNAP_CREATE: return btrfs_ioctl_snap_create(file, argp, 0); case BTRFS_IOC_SUBVOL_CREATE: -- cgit v1.2.3