[2/2,v3] Btrfs: Per file/directory controls for COW and compression

Commit Message

liubo March 22, 2011, 10:12 a.m. UTC

None

Patch

diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index 8b4b9d1..b77d1a5 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -1283,6 +1283,7 @@  struct btrfs_root {
 #define BTRFS_INODE_NODUMP		(1 << 8)
 #define BTRFS_INODE_NOATIME		(1 << 9)
 #define BTRFS_INODE_DIRSYNC		(1 << 10)
+#define BTRFS_INODE_COMPRESS		(1 << 11)
 
 /* some macros to generate set/get funcs for the struct fields.  This
  * assumes there is a lefoo_to_cpu for every type, so lets make a simple
diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index 3e1ea3e..a894c12 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -1762,6 +1762,12 @@  struct btrfs_root *open_ctree(struct super_block *sb,
 
 	btrfs_check_super_valid(fs_info, sb->s_flags & MS_RDONLY);
 
+	/*
+	 * In the long term, we'll store the compression type in the super
+	 * block, and it'll be used for per file compression control.
+	 */
+	fs_info->compress_type = BTRFS_COMPRESS_ZLIB;
+
 	ret = btrfs_parse_options(tree_root, options);
 	if (ret) {
 		err = ret;
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index db67821..2d9910d 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -381,7 +381,8 @@  again:
 	 */
 	if (!(BTRFS_I(inode)->flags & BTRFS_INODE_NOCOMPRESS) &&
 	    (btrfs_test_opt(root, COMPRESS) ||
-	     (BTRFS_I(inode)->force_compress))) {
+	     (BTRFS_I(inode)->force_compress) ||
+	     (BTRFS_I(inode)->flags & BTRFS_INODE_COMPRESS))) {
 		WARN_ON(pages);
 		pages = kzalloc(sizeof(struct page *) * nr_pages, GFP_NOFS);
 
@@ -1253,7 +1254,8 @@  static int run_delalloc_range(struct inode *inode, struct page *locked_page,
 		ret = run_delalloc_nocow(inode, locked_page, start, end,
 					 page_started, 0, nr_written);
 	else if (!btrfs_test_opt(root, COMPRESS) &&
-		 !(BTRFS_I(inode)->force_compress))
+		 !(BTRFS_I(inode)->force_compress) &&
+		 !(BTRFS_I(inode)->flags & BTRFS_INODE_COMPRESS))
 		ret = cow_file_range(inode, locked_page, start, end,
 				      page_started, nr_written, 1);
 	else
@@ -4586,7 +4588,8 @@  static struct inode *btrfs_new_inode(struct btrfs_trans_handle *trans,
 	if ((mode & S_IFREG)) {
 		if (btrfs_test_opt(root, NODATASUM))
 			BTRFS_I(inode)->flags |= BTRFS_INODE_NODATASUM;
-		if (btrfs_test_opt(root, NODATACOW))
+		if (btrfs_test_opt(root, NODATACOW) ||
+		    (BTRFS_I(dir)->flags & BTRFS_INODE_NODATACOW))
 			BTRFS_I(inode)->flags |= BTRFS_INODE_NODATACOW;
 	}
 
@@ -6803,6 +6806,26 @@  static int btrfs_getattr(struct vfsmount *mnt,
 	return 0;
 }
 
+/*
+ * If a file is moved, it will inherit the cow and compression flags of the new
+ * directory.
+ */
+static void fixup_inode_flags(struct inode *dir, struct inode *inode)
+{
+	struct btrfs_inode *b_dir = BTRFS_I(dir);
+	struct btrfs_inode *b_inode = BTRFS_I(inode);
+
+	if (b_dir->flags & BTRFS_INODE_NODATACOW)
+		b_inode->flags |= BTRFS_INODE_NODATACOW;
+	else
+		b_inode->flags &= ~BTRFS_INODE_NODATACOW;
+
+	if (b_dir->flags & BTRFS_INODE_COMPRESS)
+		b_inode->flags |= BTRFS_INODE_COMPRESS;
+	else
+		b_inode->flags &= ~BTRFS_INODE_COMPRESS;
+}
+
 static int btrfs_rename(struct inode *old_dir, struct dentry *old_dentry,
 			   struct inode *new_dir, struct dentry *new_dentry)
 {
@@ -6936,6 +6959,8 @@  static int btrfs_rename(struct inode *old_dir, struct dentry *old_dentry,
 		}
 	}
 
+	fixup_inode_flags(new_dir, old_inode);
+
 	ret = btrfs_add_link(trans, new_dir, old_inode,
 			     new_dentry->d_name.name,
 			     new_dentry->d_name.len, 0, index);
diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index 5fdb2ab..93e7f6c 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -138,6 +138,24 @@  static int btrfs_ioctl_getflags(struct file *file, void __user *arg)
 	return 0;
 }
 
+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))
+		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;
+}
+
 static int btrfs_ioctl_setflags(struct file *file, void __user *arg)
 {
 	struct inode *inode = file->f_path.dentry->d_inode;
@@ -153,10 +171,9 @@  static int btrfs_ioctl_setflags(struct file *file, void __user *arg)
 	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;
+	ret = check_flags(flags);
+	if (ret)
+		return ret;
 
 	if (!is_owner_or_cap(inode))
 		return -EACCES;
@@ -201,6 +218,22 @@  static int btrfs_ioctl_setflags(struct file *file, void __user *arg)
 	else
 		ip->flags &= ~BTRFS_INODE_DIRSYNC;
 
+	/*
+	 * The COMPRESS flag can only be changed by users, while the NOCOMPRESS
+	 * flag may be changed automatically if compression code won't make
+	 * things smaller.
+	 */
+	if (flags & FS_NOCOMP_FL) {
+		ip->flags &= ~BTRFS_INODE_COMPRESS;
+		ip->flags |= BTRFS_INODE_NOCOMPRESS;
+	} else if (flags & FS_COMPR_FL) {
+		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));