| Message ID | 4DA7B559.8060800@cn.fujitsu.com (mailing list archive) |
|---|---|
| State | Not Applicable, archived |
| Headers | show |
Any comments? If this patch is acceptable, it should be queued for .39? since fs.h is exported to userspace. Li Zefan wrote: > FS_COW_FL and FS_NOCOW_FL were newly introduced to control per file > COW in btrfs, but FS_NOCOW_FL is sufficient. > > The fact is we don't have corresponding BTRFS_INODE_COW flag. > > COW is default, and FS_NOCOW_FL can be used to switch off COW for > a single file. > > If we mount btrfs with nodatacow, a newly created file will be set with > the FS_NOCOW_FL flag. So to turn on COW for it, we can just clear the > FS_NOCOW_FL flag. > > Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> > --- > fs/btrfs/ioctl.c | 15 ++++++--------- > include/linux/fs.h | 1 - > 2 files changed, 6 insertions(+), 10 deletions(-) > > diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c > index f580a3a..3240dd9 100644 > --- a/fs/btrfs/ioctl.c > +++ b/fs/btrfs/ioctl.c > @@ -144,16 +144,13 @@ static int check_flags(unsigned int flags) > if (flags & ~(FS_IMMUTABLE_FL | FS_APPEND_FL | \ > FS_NOATIME_FL | FS_NODUMP_FL | \ > FS_SYNC_FL | FS_DIRSYNC_FL | \ > - FS_NOCOMP_FL | FS_COMPR_FL | \ > - FS_NOCOW_FL | FS_COW_FL)) > + FS_NOCOMP_FL | FS_COMPR_FL | > + FS_NOCOW_FL)) > return -EOPNOTSUPP; > > if ((flags & FS_NOCOMP_FL) && (flags & FS_COMPR_FL)) > return -EINVAL; > > - if ((flags & FS_NOCOW_FL) && (flags & FS_COW_FL)) > - return -EINVAL; > - > return 0; > } > > @@ -218,6 +215,10 @@ 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; > > /* > * The COMPRESS flag can only be changed by users, while the NOCOMPRESS > @@ -231,10 +232,6 @@ static int btrfs_ioctl_setflags(struct file *file, void __user *arg) > ip->flags |= BTRFS_INODE_COMPRESS; > ip->flags &= ~BTRFS_INODE_NOCOMPRESS; > } > - if (flags & FS_NOCOW_FL) > - ip->flags |= BTRFS_INODE_NODATACOW; > - else if (flags & FS_COW_FL) > - ip->flags &= ~BTRFS_INODE_NODATACOW; > > trans = btrfs_join_transaction(root, 1); > BUG_ON(IS_ERR(trans)); > diff --git a/include/linux/fs.h b/include/linux/fs.h > index de9dd81..56a4141 100644 > --- a/include/linux/fs.h > +++ b/include/linux/fs.h > @@ -365,7 +365,6 @@ struct inodes_stat_t { > #define FS_EXTENT_FL 0x00080000 /* Extents */ > #define FS_DIRECTIO_FL 0x00100000 /* Use direct i/o */ > #define FS_NOCOW_FL 0x00800000 /* Do not cow file */ > -#define FS_COW_FL 0x02000000 /* Cow file */ > #define FS_RESERVED_FL 0x80000000 /* reserved for ext2 lib */ > > #define FS_FL_USER_VISIBLE 0x0003DFFF /* User visible flags */ -- 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
Excerpts from Li Zefan's message of 2011-05-03 05:11:44 -0400: > Any comments? If this patch is acceptable, it should be queued for .39? > since fs.h is exported to userspace. > > Li Zefan wrote: > > FS_COW_FL and FS_NOCOW_FL were newly introduced to control per file > > COW in btrfs, but FS_NOCOW_FL is sufficient. > > Good point, I'll send this in. -chris -- 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 f580a3a..3240dd9 100644 --- a/fs/btrfs/ioctl.c +++ b/fs/btrfs/ioctl.c @@ -144,16 +144,13 @@ static int check_flags(unsigned int flags) if (flags & ~(FS_IMMUTABLE_FL | FS_APPEND_FL | \ FS_NOATIME_FL | FS_NODUMP_FL | \ FS_SYNC_FL | FS_DIRSYNC_FL | \ - FS_NOCOMP_FL | FS_COMPR_FL | \ - FS_NOCOW_FL | FS_COW_FL)) + FS_NOCOMP_FL | FS_COMPR_FL | + FS_NOCOW_FL)) return -EOPNOTSUPP; if ((flags & FS_NOCOMP_FL) && (flags & FS_COMPR_FL)) return -EINVAL; - if ((flags & FS_NOCOW_FL) && (flags & FS_COW_FL)) - return -EINVAL; - return 0; } @@ -218,6 +215,10 @@ 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; /* * The COMPRESS flag can only be changed by users, while the NOCOMPRESS @@ -231,10 +232,6 @@ static int btrfs_ioctl_setflags(struct file *file, void __user *arg) ip->flags |= BTRFS_INODE_COMPRESS; ip->flags &= ~BTRFS_INODE_NOCOMPRESS; } - if (flags & FS_NOCOW_FL) - ip->flags |= BTRFS_INODE_NODATACOW; - else if (flags & FS_COW_FL) - ip->flags &= ~BTRFS_INODE_NODATACOW; trans = btrfs_join_transaction(root, 1); BUG_ON(IS_ERR(trans)); diff --git a/include/linux/fs.h b/include/linux/fs.h index de9dd81..56a4141 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -365,7 +365,6 @@ struct inodes_stat_t { #define FS_EXTENT_FL 0x00080000 /* Extents */ #define FS_DIRECTIO_FL 0x00100000 /* Use direct i/o */ #define FS_NOCOW_FL 0x00800000 /* Do not cow file */ -#define FS_COW_FL 0x02000000 /* Cow file */ #define FS_RESERVED_FL 0x80000000 /* reserved for ext2 lib */ #define FS_FL_USER_VISIBLE 0x0003DFFF /* User visible flags */
FS_COW_FL and FS_NOCOW_FL were newly introduced to control per file COW in btrfs, but FS_NOCOW_FL is sufficient. The fact is we don't have corresponding BTRFS_INODE_COW flag. COW is default, and FS_NOCOW_FL can be used to switch off COW for a single file. If we mount btrfs with nodatacow, a newly created file will be set with the FS_NOCOW_FL flag. So to turn on COW for it, we can just clear the FS_NOCOW_FL flag. Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> --- fs/btrfs/ioctl.c | 15 ++++++--------- include/linux/fs.h | 1 - 2 files changed, 6 insertions(+), 10 deletions(-)