diff options
Diffstat (limited to 'fs/btrfs/ioctl.c')
| -rw-r--r-- | fs/btrfs/ioctl.c | 31 |
1 files changed, 27 insertions, 4 deletions
diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c index 38e3d6ab89d..4d7f4bbf4c9 100644 --- a/fs/btrfs/ioctl.c +++ b/fs/btrfs/ioctl.c @@ -181,6 +181,7 @@ static int btrfs_ioctl_setflags(struct file *file, void __user *arg) int ret; u64 ip_oldflags; unsigned int i_oldflags; + umode_t mode; if (btrfs_root_readonly(root)) return -EROFS; @@ -203,6 +204,7 @@ static int btrfs_ioctl_setflags(struct file *file, void __user *arg) ip_oldflags = ip->flags; i_oldflags = inode->i_flags; + mode = inode->i_mode; flags = btrfs_mask_flags(inode->i_mode, flags); oldflags = btrfs_flags_to_ioctl(ip->flags); @@ -237,10 +239,31 @@ static int btrfs_ioctl_setflags(struct file *file, void __user *arg) ip->flags |= BTRFS_INODE_DIRSYNC; else ip->flags &= ~BTRFS_INODE_DIRSYNC; - if (flags & FS_NOCOW_FL) - ip->flags |= BTRFS_INODE_NODATACOW; - else - ip->flags &= ~BTRFS_INODE_NODATACOW; + if (flags & FS_NOCOW_FL) { + if (S_ISREG(mode)) { + /* + * It's safe to turn csums off here, no extents exist. + * Otherwise we want the flag to reflect the real COW + * status of the file and will not set it. + */ + if (inode->i_size == 0) + ip->flags |= BTRFS_INODE_NODATACOW + | BTRFS_INODE_NODATASUM; + } else { + ip->flags |= BTRFS_INODE_NODATACOW; + } + } else { + /* + * Revert back under same assuptions as above + */ + if (S_ISREG(mode)) { + if (inode->i_size == 0) + ip->flags &= ~(BTRFS_INODE_NODATACOW + | BTRFS_INODE_NODATASUM); + } else { + ip->flags &= ~BTRFS_INODE_NODATACOW; + } + } /* * The COMPRESS flag can only be changed by users, while the NOCOMPRESS |