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Btrfs: add new defrag-range ioctl.

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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>
This commit is contained in:
Chris Mason 2010-03-11 09:42:04 -05:00
parent 940100a4a7
commit 1e701a3292
5 changed files with 117 additions and 14 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

5
fs/btrfs/btrfs_inode.h
View File

@ -153,6 +153,11 @@ struct btrfs_inode {
unsigned ordered_data_close:1;
unsigned dummy_inode:1;
/*
* always compress this one file
*/
unsigned force_compress:1;
struct inode vfs_inode;
};

1
fs/btrfs/ctree.h
View File

@ -1184,7 +1184,6 @@ struct btrfs_root {
#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:

11
fs/btrfs/inode.c
View File

@ -379,7 +379,8 @@ again:
* 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 @@ again:
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 @@ static int run_delalloc_range(struct inode *inode, struct page *locked_page,
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 @@ static noinline void init_btrfs_i(struct inode *inode)
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);

83
fs/btrfs/ioctl.c
View File

@ -476,13 +476,18 @@ out_unlock:
}
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 @@ static int should_defrag_range(struct inode *inode, u64 start, u64 len,
/*
* 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 @@ static int should_defrag_range(struct inode *inode, u64 start, u64 len,
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 @@ static int btrfs_defrag_file(struct file *file)
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 @@ static int btrfs_defrag_file(struct file *file)
}
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 @@ loop_unlock:
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 @@ out:
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 @@ static int btrfs_ioctl_defrag(struct file *file)
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 @@ long btrfs_ioctl(struct file *file, unsigned int
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:

31
fs/btrfs/ioctl.h
View File

@ -99,6 +99,35 @@ struct btrfs_ioctl_clone_range_args {
__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_clone_range_args {
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, \