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authorLiu Bo <liubo2009@cn.fujitsu.com>2011-03-22 10:12:20 +0000
committerroot <Chris Mason chris.mason@oracle.com>2011-03-28 05:37:41 -0400
commit75e7cb7fe0c391561bd3af36515be3f3c64a04c6 (patch)
tree3738481e2db10b2904a4434e4ca42d326da02be7 /fs/btrfs/inode.c
parent32471f6e1983922473573da62cbee58699574aa4 (diff)
Btrfs: Per file/directory controls for COW and compression
Data compression and data cow are controlled across the entire FS by mount options right now. ioctls are needed to set this on a per file or per directory basis. This has been proposed previously, but VFS developers wanted us to use generic ioctls rather than btrfs-specific ones. According to Chris's comment, there should be just one true compression method(probably LZO) stored in the super. However, before this, we would wait for that one method is stable enough to be adopted into the super. So I list it as a long term goal, and just store it in ram today. After applying this patch, we can use the generic "FS_IOC_SETFLAGS" ioctl to control file and directory's datacow and compression attribute. NOTE: - The compression type is selected by such rules: If we mount btrfs with compress options, ie, zlib/lzo, the type is it. Otherwise, we'll use the default compress type (zlib today). v1->v2: - rebase to the latest btrfs. v2->v3: - fix a problem, i.e. when a file is set NOCOW via mount option, then this NOCOW will be screwed by inheritance from parent directory. Signed-off-by: Liu Bo <liubo2009@cn.fujitsu.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
Diffstat (limited to 'fs/btrfs/inode.c')
-rw-r--r--fs/btrfs/inode.c31
1 files changed, 28 insertions, 3 deletions
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index eaa27148419..7a7a202b82a 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -384,7 +384,8 @@ 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);
@@ -1256,7 +1257,8 @@ 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
@@ -4584,7 +4586,8 @@ 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;
}
@@ -6866,6 +6869,26 @@ 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)
{
@@ -6999,6 +7022,8 @@ 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);