Btrfs: add new defrag-range ioctl.
The btrfs defrag ioctl was limited to doing the entire file. This
commit adds a new interface that can defrag a specific range inside
the file.
It can also force compression on the file, allowing you to selectively
compress individual files after they were created, even when mount -o
compress isn't turned on.
Signed-off-by: Chris Mason <chris.mason@oracle.com>
diff --git a/fs/btrfs/btrfs_inode.h b/fs/btrfs/btrfs_inode.h
index 3f1f50d..7a4dee1 100644
--- a/fs/btrfs/btrfs_inode.h
+++ b/fs/btrfs/btrfs_inode.h
@@ -153,6 +153,11 @@
unsigned ordered_data_close:1;
unsigned dummy_inode:1;
+ /*
+ * always compress this one file
+ */
+ unsigned force_compress:1;
+
struct inode vfs_inode;
};
diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index 1166b15..3a36b1f 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -1184,7 +1184,6 @@
#define BTRFS_INODE_NOATIME (1 << 9)
#define BTRFS_INODE_DIRSYNC (1 << 10)
-
/* 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
* one for u8:
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 7d10d1c..3657925 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -379,7 +379,8 @@
* change at any time if we discover bad compression ratios.
*/
if (!(BTRFS_I(inode)->flags & BTRFS_INODE_NOCOMPRESS) &&
- btrfs_test_opt(root, COMPRESS)) {
+ (btrfs_test_opt(root, COMPRESS) ||
+ (BTRFS_I(inode)->force_compress))) {
WARN_ON(pages);
pages = kzalloc(sizeof(struct page *) * nr_pages, GFP_NOFS);
@@ -483,8 +484,10 @@
nr_pages_ret = 0;
/* flag the file so we don't compress in the future */
- if (!btrfs_test_opt(root, FORCE_COMPRESS))
+ if (!btrfs_test_opt(root, FORCE_COMPRESS) &&
+ !(BTRFS_I(inode)->force_compress)) {
BTRFS_I(inode)->flags |= BTRFS_INODE_NOCOMPRESS;
+ }
}
if (will_compress) {
*num_added += 1;
@@ -1211,7 +1214,8 @@
else if (BTRFS_I(inode)->flags & BTRFS_INODE_PREALLOC)
ret = run_delalloc_nocow(inode, locked_page, start, end,
page_started, 0, nr_written);
- else if (!btrfs_test_opt(root, COMPRESS))
+ else if (!btrfs_test_opt(root, COMPRESS) &&
+ !(BTRFS_I(inode)->force_compress))
ret = cow_file_range(inode, locked_page, start, end,
page_started, nr_written, 1);
else
@@ -3639,6 +3643,7 @@
bi->index_cnt = (u64)-1;
bi->last_unlink_trans = 0;
bi->ordered_data_close = 0;
+ bi->force_compress = 0;
extent_map_tree_init(&BTRFS_I(inode)->extent_tree, GFP_NOFS);
extent_io_tree_init(&BTRFS_I(inode)->io_tree,
inode->i_mapping, GFP_NOFS);
diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index 3a89cd7..d866b46 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -476,13 +476,18 @@
}
static int should_defrag_range(struct inode *inode, u64 start, u64 len,
- u64 *last_len, u64 *skip, u64 *defrag_end)
+ int thresh, u64 *last_len, u64 *skip,
+ u64 *defrag_end)
{
struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
struct extent_map *em = NULL;
struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
int ret = 1;
+
+ if (thresh == 0)
+ thresh = 256 * 1024;
+
/*
* make sure that once we start defragging and extent, we keep on
* defragging it
@@ -517,8 +522,7 @@
/*
* we hit a real extent, if it is big don't bother defragging it again
*/
- if ((*last_len == 0 || *last_len >= 256 * 1024) &&
- em->len >= 256 * 1024)
+ if ((*last_len == 0 || *last_len >= thresh) && em->len >= thresh)
ret = 0;
/*
@@ -542,7 +546,8 @@
return ret;
}
-static int btrfs_defrag_file(struct file *file)
+static int btrfs_defrag_file(struct file *file,
+ struct btrfs_ioctl_defrag_range_args *range)
{
struct inode *inode = fdentry(file)->d_inode;
struct btrfs_root *root = BTRFS_I(inode)->root;
@@ -563,11 +568,19 @@
if (inode->i_size == 0)
return 0;
- last_index = (inode->i_size - 1) >> PAGE_CACHE_SHIFT;
- i = 0;
+ if (range->start + range->len > range->start) {
+ last_index = min_t(u64, inode->i_size - 1,
+ range->start + range->len - 1) >> PAGE_CACHE_SHIFT;
+ } else {
+ last_index = (inode->i_size - 1) >> PAGE_CACHE_SHIFT;
+ }
+
+ i = range->start >> PAGE_CACHE_SHIFT;
while (i <= last_index) {
if (!should_defrag_range(inode, (u64)i << PAGE_CACHE_SHIFT,
- PAGE_CACHE_SIZE, &last_len, &skip,
+ PAGE_CACHE_SIZE,
+ range->extent_thresh,
+ &last_len, &skip,
&defrag_end)) {
unsigned long next;
/*
@@ -585,6 +598,8 @@
}
total_read++;
mutex_lock(&inode->i_mutex);
+ if (range->flags & BTRFS_DEFRAG_RANGE_COMPRESS)
+ BTRFS_I(inode)->force_compress = 1;
ret = btrfs_check_data_free_space(root, inode, PAGE_CACHE_SIZE);
if (ret) {
@@ -673,6 +688,28 @@
i++;
}
+ if ((range->flags & BTRFS_DEFRAG_RANGE_START_IO))
+ filemap_flush(inode->i_mapping);
+
+ if ((range->flags & BTRFS_DEFRAG_RANGE_COMPRESS)) {
+ /* the filemap_flush will queue IO into the worker threads, but
+ * we have to make sure the IO is actually started and that
+ * ordered extents get created before we return
+ */
+ atomic_inc(&root->fs_info->async_submit_draining);
+ while (atomic_read(&root->fs_info->nr_async_submits) ||
+ atomic_read(&root->fs_info->async_delalloc_pages)) {
+ wait_event(root->fs_info->async_submit_wait,
+ (atomic_read(&root->fs_info->nr_async_submits) == 0 &&
+ atomic_read(&root->fs_info->async_delalloc_pages) == 0));
+ }
+ atomic_dec(&root->fs_info->async_submit_draining);
+
+ mutex_lock(&inode->i_mutex);
+ BTRFS_I(inode)->force_compress = 0;
+ mutex_unlock(&inode->i_mutex);
+ }
+
return 0;
err_reservations:
@@ -1284,10 +1321,11 @@
return err;
}
-static int btrfs_ioctl_defrag(struct file *file)
+static int btrfs_ioctl_defrag(struct file *file, void __user *argp)
{
struct inode *inode = fdentry(file)->d_inode;
struct btrfs_root *root = BTRFS_I(inode)->root;
+ struct btrfs_ioctl_defrag_range_args *range;
int ret;
ret = mnt_want_write(file->f_path.mnt);
@@ -1308,7 +1346,30 @@
ret = -EINVAL;
goto out;
}
- btrfs_defrag_file(file);
+
+ range = kzalloc(sizeof(*range), GFP_KERNEL);
+ if (!range) {
+ ret = -ENOMEM;
+ goto out;
+ }
+
+ if (argp) {
+ if (copy_from_user(range, argp,
+ sizeof(*range))) {
+ ret = -EFAULT;
+ kfree(range);
+ }
+ /* compression requires us to start the IO */
+ if ((range->flags & BTRFS_DEFRAG_RANGE_COMPRESS)) {
+ range->flags |= BTRFS_DEFRAG_RANGE_START_IO;
+ range->extent_thresh = (u32)-1;
+ }
+ } else {
+ /* the rest are all set to zero by kzalloc */
+ range->len = (u64)-1;
+ }
+ btrfs_defrag_file(file, range);
+ kfree(range);
break;
}
out:
@@ -1831,7 +1892,9 @@
case BTRFS_IOC_DEFAULT_SUBVOL:
return btrfs_ioctl_default_subvol(file, argp);
case BTRFS_IOC_DEFRAG:
- return btrfs_ioctl_defrag(file);
+ return btrfs_ioctl_defrag(file, NULL);
+ case BTRFS_IOC_DEFRAG_RANGE:
+ return btrfs_ioctl_defrag(file, argp);
case BTRFS_IOC_RESIZE:
return btrfs_ioctl_resize(root, argp);
case BTRFS_IOC_ADD_DEV:
diff --git a/fs/btrfs/ioctl.h b/fs/btrfs/ioctl.h
index f1923e0..2d64a65 100644
--- a/fs/btrfs/ioctl.h
+++ b/fs/btrfs/ioctl.h
@@ -99,6 +99,35 @@
__u64 dest_offset;
};
+/* flags for the defrag range ioctl */
+#define BTRFS_DEFRAG_RANGE_COMPRESS 1
+#define BTRFS_DEFRAG_RANGE_START_IO 2
+
+struct btrfs_ioctl_defrag_range_args {
+ /* start of the defrag operation */
+ __u64 start;
+
+ /* number of bytes to defrag, use (u64)-1 to say all */
+ __u64 len;
+
+ /*
+ * flags for the operation, which can include turning
+ * on compression for this one defrag
+ */
+ __u64 flags;
+
+ /*
+ * any extent bigger than this will be considered
+ * already defragged. Use 0 to take the kernel default
+ * Use 1 to say every single extent must be rewritten
+ */
+ __u32 extent_thresh;
+
+ /* spare for later */
+ __u32 unused[5];
+};
+
+
#define BTRFS_IOC_SNAP_CREATE _IOW(BTRFS_IOCTL_MAGIC, 1, \
struct btrfs_ioctl_vol_args)
#define BTRFS_IOC_DEFRAG _IOW(BTRFS_IOCTL_MAGIC, 2, \
@@ -130,6 +159,8 @@
struct btrfs_ioctl_vol_args)
#define BTRFS_IOC_SNAP_DESTROY _IOW(BTRFS_IOCTL_MAGIC, 15, \
struct btrfs_ioctl_vol_args)
+#define BTRFS_IOC_DEFRAG_RANGE _IOW(BTRFS_IOCTL_MAGIC, 16, \
+ struct btrfs_ioctl_defrag_range_args)
#define BTRFS_IOC_TREE_SEARCH _IOWR(BTRFS_IOCTL_MAGIC, 17, \
struct btrfs_ioctl_search_args)
#define BTRFS_IOC_INO_LOOKUP _IOWR(BTRFS_IOCTL_MAGIC, 18, \