From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mingming Subject: [PATCH] COW and checksumming ioctls Date: Thu, 19 Jun 2008 17:26:48 -0700 Message-ID: <1213921608.27507.152.camel@BVR-FS.beaverton.ibm.com> Mime-Version: 1.0 Content-Type: text/plain To: linux-btrfs@vger.kernel.org Return-path: List-ID: COW and checksumming is enabled by default, and could be disable with mount option. These new ioctls below let a user application turn on/off copy-on-write and checksumming on a per file basis. Signed-off-by: Mingming Cao diff -r 79b81fd6dd78 ioctl.c --- a/ioctl.c Thu Jun 12 14:46:17 2008 -0400 +++ b/ioctl.c Thu Jun 19 15:59:02 2008 -0700 @@ -471,6 +471,55 @@ static int btrfs_ioctl_defrag(struct fil return 0; } + +static int btrfs_ioctl_disable_datacow(struct file *file) +{ + struct inode *inode = fdentry(file)->d_inode; + + if ((inode->i_mode & S_IFMT) == S_IFREG) { + mutex_lock(&inode->i_mutex); + btrfs_set_flag(inode, NODATACOW); + mutex_unlock(&inode->i_mutex); + } + + return 0; +} + +static int btrfs_ioctl_enable_datacow(struct file *file) +{ + struct inode *inode = fdentry(file)->d_inode; + + if ((inode->i_mode & S_IFMT) == S_IFREG) { + mutex_lock(&inode->i_mutex); + btrfs_clear_flag(inode, NODATACOW); + mutex_unlock(&inode->i_mutex); + } + + return 0; +} + +static int btrfs_ioctl_disable_datasum(struct file *file) +{ + struct inode *inode = fdentry(file)->d_inode; + + mutex_lock(&inode->i_mutex); + btrfs_set_flag(inode, NODATASUM); + mutex_unlock(&inode->i_mutex); + + return 0; +} + +static int btrfs_ioctl_enable_datasum(struct file *file) +{ + struct inode *inode = fdentry(file)->d_inode; + + mutex_lock(&inode->i_mutex); + btrfs_clear_flag(inode, NODATASUM); + mutex_unlock(&inode->i_mutex); + + return 0; +} + long btrfs_ioctl_add_dev(struct btrfs_root *root, void __user *arg) { @@ -775,6 +824,14 @@ long btrfs_ioctl(struct file *file, unsi return btrfs_ioctl_trans_start(file); case BTRFS_IOC_TRANS_END: return btrfs_ioctl_trans_end(file); + case BTRFS_IOC_NODATACOW: + return btrfs_ioctl_disable_datacow(file); + case BTRFS_IOC_DATACOW: + return btrfs_ioctl_enable_datacow(file); + case BTRFS_IOC_NODATASUM: + return btrfs_ioctl_disable_datasum(file); + case BTRFS_IOC_DATASUM: + return btrfs_ioctl_enable_datasum(file); case BTRFS_IOC_SYNC: btrfs_sync_fs(file->f_dentry->d_sb, 1); return 0; diff -r 79b81fd6dd78 ioctl.h --- a/ioctl.h Thu Jun 12 14:46:17 2008 -0400 +++ b/ioctl.h Thu Jun 19 15:32:40 2008 -0700 @@ -51,5 +51,8 @@ struct btrfs_ioctl_vol_args { struct btrfs_ioctl_vol_args) #define BTRFS_IOC_BALANCE _IOW(BTRFS_IOCTL_MAGIC, 12, \ struct btrfs_ioctl_vol_args) - +#define BTRFS_IOC_NODATACOW _IO(BTRFS_IOCTL_MAGIC, 13) +#define BTRFS_IOC_DATACOW _IO(BTRFS_IOCTL_MAGIC, 14) +#define BTRFS_IOC_NODATASUM _IO(BTRFS_IOCTL_MAGIC, 15) +#define BTRFS_IOC_DATASUM _IO(BTRFS_IOCTL_MAGIC, 16) #endif