[Ocfs2-devel] [PATCH 6/6] ocfs2: implement the VFS clone_range, copy_range, and dedupe_range features

Eric Ren zren at suse.com
Thu Nov 10 21:49:48 PST 2016


Hi,

A few issues obvious to me:

On 11/10/2016 06:51 AM, Darrick J. Wong wrote:
> Connect the new VFS clone_range, copy_range, and dedupe_range features
> to the existing reflink capability of ocfs2.  Compared to the existing
> ocfs2 reflink ioctl We have to do things a little differently to support
> the VFS semantics (we can clone subranges of a file but we don't clone
> xattrs), but the VFS ioctls are more broadly supported.

How can I test the new ocfs2 reflink (with this patch) manually? What commands should I
use to do xxx_range things?

>
> Signed-off-by: Darrick J. Wong <darrick.wong at oracle.com>
> ---
>   fs/ocfs2/file.c         |   62 ++++-
>   fs/ocfs2/file.h         |    3
>   fs/ocfs2/refcounttree.c |  619 +++++++++++++++++++++++++++++++++++++++++++++++
>   fs/ocfs2/refcounttree.h |    7 +
>   4 files changed, 688 insertions(+), 3 deletions(-)
>
>
> diff --git a/fs/ocfs2/file.c b/fs/ocfs2/file.c
> index 000c234..d5a022d 100644
> --- a/fs/ocfs2/file.c
> +++ b/fs/ocfs2/file.c
> @@ -1667,9 +1667,9 @@ static void ocfs2_calc_trunc_pos(struct inode *inode,
>   	*done = ret;
>   }
>   
> -static int ocfs2_remove_inode_range(struct inode *inode,
> -				    struct buffer_head *di_bh, u64 byte_start,
> -				    u64 byte_len)
> +int ocfs2_remove_inode_range(struct inode *inode,
> +			     struct buffer_head *di_bh, u64 byte_start,
> +			     u64 byte_len)
>   {
>   	int ret = 0, flags = 0, done = 0, i;
>   	u32 trunc_start, trunc_len, trunc_end, trunc_cpos, phys_cpos;
> @@ -2440,6 +2440,56 @@ static loff_t ocfs2_file_llseek(struct file *file, loff_t offset, int whence)
>   	return offset;
>   }
>   
> +static ssize_t ocfs2_file_copy_range(struct file *file_in,
> +				     loff_t pos_in,
> +				     struct file *file_out,
> +				     loff_t pos_out,
> +				     size_t len,
> +				     unsigned int flags)
> +{
> +	int error;
> +
> +	error = ocfs2_reflink_remap_range(file_in, pos_in, file_out, pos_out,
> +					  len, false);
> +	if (error)
> +		return error;
> +	return len;
> +}
> +
> +static int ocfs2_file_clone_range(struct file *file_in,
> +				  loff_t pos_in,
> +				  struct file *file_out,
> +				  loff_t pos_out,
> +				  u64 len)
> +{
> +	return ocfs2_reflink_remap_range(file_in, pos_in, file_out, pos_out,
> +					 len, false);
> +}
> +
> +#define OCFS2_MAX_DEDUPE_LEN	(16 * 1024 * 1024)
> +static ssize_t ocfs2_file_dedupe_range(struct file *src_file,
> +				       u64 loff,
> +				       u64 len,
> +				       struct file *dst_file,
> +				       u64 dst_loff)
> +{
> +	int error;
> +
> +	/*
> +	 * Limit the total length we will dedupe for each operation.
> +	 * This is intended to bound the total time spent in this
> +	 * ioctl to something sane.
> +	 */
> +	if (len > OCFS2_MAX_DEDUPE_LEN)
> +		len = OCFS2_MAX_DEDUPE_LEN;
> +
> +	error = ocfs2_reflink_remap_range(src_file, loff, dst_file, dst_loff,
> +					  len, true);
> +	if (error)
> +		return error;
> +	return len;
> +}
> +
>   const struct inode_operations ocfs2_file_iops = {
>   	.setattr	= ocfs2_setattr,
>   	.getattr	= ocfs2_getattr,
> @@ -2479,6 +2529,9 @@ const struct file_operations ocfs2_fops = {
>   	.splice_read	= generic_file_splice_read,
>   	.splice_write	= iter_file_splice_write,
>   	.fallocate	= ocfs2_fallocate,
> +	.copy_file_range = ocfs2_file_copy_range,
> +	.clone_file_range = ocfs2_file_clone_range,
> +	.dedupe_file_range = ocfs2_file_dedupe_range,
>   };
>   
>   const struct file_operations ocfs2_dops = {
> @@ -2524,6 +2577,9 @@ const struct file_operations ocfs2_fops_no_plocks = {
>   	.splice_read	= generic_file_splice_read,
>   	.splice_write	= iter_file_splice_write,
>   	.fallocate	= ocfs2_fallocate,
> +	.copy_file_range = ocfs2_file_copy_range,
> +	.clone_file_range = ocfs2_file_clone_range,
> +	.dedupe_file_range = ocfs2_file_dedupe_range,
>   };
>   
>   const struct file_operations ocfs2_dops_no_plocks = {
> diff --git a/fs/ocfs2/file.h b/fs/ocfs2/file.h
> index e8c62f2..897fd9a 100644
> --- a/fs/ocfs2/file.h
> +++ b/fs/ocfs2/file.h
> @@ -82,4 +82,7 @@ int ocfs2_change_file_space(struct file *file, unsigned int cmd,
>   
>   int ocfs2_check_range_for_refcount(struct inode *inode, loff_t pos,
>   				   size_t count);
> +int ocfs2_remove_inode_range(struct inode *inode,
> +			     struct buffer_head *di_bh, u64 byte_start,
> +			     u64 byte_len);
>   #endif /* OCFS2_FILE_H */
> diff --git a/fs/ocfs2/refcounttree.c b/fs/ocfs2/refcounttree.c
> index d92b6c6..3e2198c 100644
> --- a/fs/ocfs2/refcounttree.c
> +++ b/fs/ocfs2/refcounttree.c
> @@ -34,6 +34,7 @@
>   #include "xattr.h"
>   #include "namei.h"
>   #include "ocfs2_trace.h"
> +#include "file.h"
>   
>   #include <linux/bio.h>
>   #include <linux/blkdev.h>
> @@ -4447,3 +4448,621 @@ int ocfs2_reflink_ioctl(struct inode *inode,
>   
>   	return error;
>   }
> +
> +/* Update destination inode size, if necessary. */
> +static int ocfs2_reflink_update_dest(struct inode *dest,
> +				     struct buffer_head *d_bh,
> +				     loff_t newlen)
> +{
> +	handle_t *handle;
> +	struct ocfs2_dinode *di = (struct ocfs2_dinode *)d_bh->b_data;
> +	int ret;
> +
> +	if (newlen <= i_size_read(dest))
> +		return 0;
> +
> +	handle = ocfs2_start_trans(OCFS2_SB(dest->i_sb),
> +				   OCFS2_INODE_UPDATE_CREDITS);
> +	if (IS_ERR(handle)) {
> +		ret = PTR_ERR(handle);
> +		mlog_errno(ret);
> +		return ret;
> +	}
> +
> +	ret = ocfs2_journal_access_di(handle, INODE_CACHE(dest), d_bh,
> +				      OCFS2_JOURNAL_ACCESS_WRITE);
> +	if (ret) {
> +		mlog_errno(ret);
> +		goto out_commit;
> +	}
> +
> +	spin_lock(&OCFS2_I(dest)->ip_lock);
> +	if (newlen > i_size_read(dest)) {
> +		i_size_write(dest, newlen);
> +		di->i_size = newlen;

di->i_size = cpu_to_le64(newlen);

> +	}
> +	spin_unlock(&OCFS2_I(dest)->ip_lock);
> +

Add ocfs2_update_inode_fsync_trans() here? Looks this function was introduced by you to 
improve efficiency.
Just want to awake your memory about this, though I don't know about the details why it 
should be.

Eric

> +	ocfs2_journal_dirty(handle, d_bh);
> +
> +out_commit:
> +	ocfs2_commit_trans(OCFS2_SB(dest->i_sb), handle);
> +	return ret;
> +}
> +
> +/* Remap the range pos_in:len in s_inode to pos_out:len in t_inode. */
> +static int ocfs2_reflink_remap_extent(struct inode *s_inode,
> +				      struct buffer_head *s_bh,
> +				      loff_t pos_in,
> +				      struct inode *t_inode,
> +				      struct buffer_head *t_bh,
> +				      loff_t pos_out,
> +				      loff_t len,
> +				      struct ocfs2_cached_dealloc_ctxt *dealloc)
> +{
> +	struct ocfs2_extent_tree s_et;
> +	struct ocfs2_extent_tree t_et;
> +	struct ocfs2_dinode *dis;
> +	struct buffer_head *ref_root_bh = NULL;
> +	struct ocfs2_refcount_tree *ref_tree;
> +	struct ocfs2_super *osb;
> +	loff_t pstart, plen;
> +	u32 p_cluster, num_clusters, slast, spos, tpos;
> +	unsigned int ext_flags;
> +	int ret = 0;
> +
> +	osb = OCFS2_SB(s_inode->i_sb);
> +	dis = (struct ocfs2_dinode *)s_bh->b_data;
> +	ocfs2_init_dinode_extent_tree(&s_et, INODE_CACHE(s_inode), s_bh);
> +	ocfs2_init_dinode_extent_tree(&t_et, INODE_CACHE(t_inode), t_bh);
> +
> +	spos = ocfs2_bytes_to_clusters(s_inode->i_sb, pos_in);
> +	tpos = ocfs2_bytes_to_clusters(t_inode->i_sb, pos_out);
> +	slast = ocfs2_clusters_for_bytes(s_inode->i_sb, pos_in + len);
> +
> +	while (spos < slast) {
> +		if (fatal_signal_pending(current)) {
> +			ret = -EINTR;
> +			goto out;
> +		}
> +
> +		/* Look up the extent. */
> +		ret = ocfs2_get_clusters(s_inode, spos, &p_cluster,
> +					 &num_clusters, &ext_flags);
> +		if (ret) {
> +			mlog_errno(ret);
> +			goto out;
> +		}
> +
> +		num_clusters = min_t(u32, num_clusters, slast - spos);
> +
> +		/* Punch out the dest range. */
> +		pstart = ocfs2_clusters_to_bytes(t_inode->i_sb, tpos);
> +		plen = ocfs2_clusters_to_bytes(t_inode->i_sb, num_clusters);
> +		ret = ocfs2_remove_inode_range(t_inode, t_bh, pstart, plen);
> +		if (ret) {
> +			mlog_errno(ret);
> +			goto out;
> +		}
> +
> +		if (p_cluster == 0)
> +			goto next_loop;
> +
> +		/* Lock the refcount btree... */
> +		ret = ocfs2_lock_refcount_tree(osb,
> +					       le64_to_cpu(dis->i_refcount_loc),
> +					       1, &ref_tree, &ref_root_bh);
> +		if (ret) {
> +			mlog_errno(ret);
> +			goto out;
> +		}
> +
> +		/* Mark s_inode's extent as refcounted. */
> +		if (!(ext_flags & OCFS2_EXT_REFCOUNTED)) {
> +			ret = ocfs2_add_refcount_flag(s_inode, &s_et,
> +						      &ref_tree->rf_ci,
> +						      ref_root_bh, spos,
> +						      p_cluster, num_clusters,
> +						      dealloc, NULL);
> +			if (ret) {
> +				mlog_errno(ret);
> +				goto out_unlock_refcount;
> +			}
> +		}
> +
> +		/* Map in the new extent. */
> +		ext_flags |= OCFS2_EXT_REFCOUNTED;
> +		ret = ocfs2_add_refcounted_extent(t_inode, &t_et,
> +						  &ref_tree->rf_ci,
> +						  ref_root_bh,
> +						  tpos, p_cluster,
> +						  num_clusters,
> +						  ext_flags,
> +						  dealloc);
> +		if (ret) {
> +			mlog_errno(ret);
> +			goto out_unlock_refcount;
> +		}
> +
> +		ocfs2_unlock_refcount_tree(osb, ref_tree, 1);
> +		brelse(ref_root_bh);
> +next_loop:
> +		spos += num_clusters;
> +		tpos += num_clusters;
> +	}
> +
> +out:
> +	return ret;
> +out_unlock_refcount:
> +	ocfs2_unlock_refcount_tree(osb, ref_tree, 1);
> +	brelse(ref_root_bh);
> +	return ret;
> +}
> +
> +/* Set up refcount tree and remap s_inode to t_inode. */
> +static int ocfs2_reflink_remap_blocks(struct inode *s_inode,
> +				      struct buffer_head *s_bh,
> +				      loff_t pos_in,
> +				      struct inode *t_inode,
> +				      struct buffer_head *t_bh,
> +				      loff_t pos_out,
> +				      loff_t len)
> +{
> +	struct ocfs2_cached_dealloc_ctxt dealloc;
> +	struct ocfs2_super *osb;
> +	struct ocfs2_dinode *dis;
> +	struct ocfs2_dinode *dit;
> +	int ret;
> +
> +	osb = OCFS2_SB(s_inode->i_sb);
> +	dis = (struct ocfs2_dinode *)s_bh->b_data;
> +	dit = (struct ocfs2_dinode *)t_bh->b_data;
> +	ocfs2_init_dealloc_ctxt(&dealloc);
> +
> +	/*
> +	 * If both inodes belong to two different refcount groups then
> +	 * forget it because we don't know how (or want) to go merging
> +	 * refcount trees.
> +	 */
> +	ret = -EOPNOTSUPP;
> +	if (ocfs2_is_refcount_inode(s_inode) &&
> +	    ocfs2_is_refcount_inode(t_inode) &&
> +	    le64_to_cpu(dis->i_refcount_loc) !=
> +	    le64_to_cpu(dit->i_refcount_loc))
> +		goto out;
> +
> +	/* Neither inode has a refcount tree.  Add one to s_inode. */
> +	if (!ocfs2_is_refcount_inode(s_inode) &&
> +	    !ocfs2_is_refcount_inode(t_inode)) {
> +		ret = ocfs2_create_refcount_tree(s_inode, s_bh);
> +		if (ret) {
> +			mlog_errno(ret);
> +			goto out;
> +		}
> +	}
> +
> +	/* Ensure that both inodes end up with the same refcount tree. */
> +	if (!ocfs2_is_refcount_inode(s_inode)) {
> +		ret = ocfs2_set_refcount_tree(s_inode, s_bh,
> +					      le64_to_cpu(dit->i_refcount_loc));
> +		if (ret) {
> +			mlog_errno(ret);
> +			goto out;
> +		}
> +	}
> +	if (!ocfs2_is_refcount_inode(t_inode)) {
> +		ret = ocfs2_set_refcount_tree(t_inode, t_bh,
> +					      le64_to_cpu(dis->i_refcount_loc));
> +		if (ret) {
> +			mlog_errno(ret);
> +			goto out;
> +		}
> +	}
> +
> +	/*
> +	 * If we're reflinking the entire file and the source is inline
> +	 * data, just copy the contents.
> +	 */
> +	if (pos_in == pos_out && pos_in == 0 && len == i_size_read(s_inode) &&
> +	    i_size_read(t_inode) <= len &&
> +	    (OCFS2_I(s_inode)->ip_dyn_features & OCFS2_INLINE_DATA_FL)) {
> +		ret = ocfs2_duplicate_inline_data(s_inode, s_bh, t_inode, t_bh);
> +		if (ret)
> +			mlog_errno(ret);
> +		goto out;
> +	}
> +
> +	ret = ocfs2_reflink_remap_extent(s_inode, s_bh, pos_in, t_inode, t_bh,
> +					 pos_out, len, &dealloc);
> +	if (ret) {
> +		mlog_errno(ret);
> +		goto out;
> +	}
> +
> +out:
> +	if (ocfs2_dealloc_has_cluster(&dealloc)) {
> +		ocfs2_schedule_truncate_log_flush(osb, 1);
> +		ocfs2_run_deallocs(osb, &dealloc);
> +	}
> +
> +	return ret;
> +}
> +
> +/* Lock an inode and grab a bh pointing to the inode. */
> +static int ocfs2_reflink_inodes_lock(struct inode *s_inode,
> +				     struct buffer_head **bh1,
> +				     struct inode *t_inode,
> +				     struct buffer_head **bh2)
> +{
> +	struct inode *inode1;
> +	struct inode *inode2;
> +	struct ocfs2_inode_info *oi1;
> +	struct ocfs2_inode_info *oi2;
> +	bool same_inode = (s_inode == t_inode);
> +	int status;
> +
> +	/* First grab the VFS and rw locks. */
> +	inode1 = s_inode;
> +	inode2 = t_inode;
> +	if (inode1->i_ino > inode2->i_ino)
> +		swap(inode1, inode2);
> +
> +	inode_lock(inode1);
> +	status = ocfs2_rw_lock(inode1, 1);
> +	if (status) {
> +		mlog_errno(status);
> +		goto out_i1;
> +	}
> +	if (!same_inode) {
> +		inode_lock_nested(inode2, I_MUTEX_CHILD);
> +		status = ocfs2_rw_lock(inode2, 1);
> +		if (status) {
> +			mlog_errno(status);
> +			goto out_i2;
> +		}
> +	}
> +
> +	/* Now go for the cluster locks */
> +	oi1 = OCFS2_I(inode1);
> +	oi2 = OCFS2_I(inode2);
> +
> +	trace_ocfs2_double_lock((unsigned long long)oi1->ip_blkno,
> +				(unsigned long long)oi2->ip_blkno);
> +
> +	if (*bh1)
> +		*bh1 = NULL;
> +	if (*bh2)
> +		*bh2 = NULL;
> +
> +	/* We always want to lock the one with the lower lockid first. */
> +	if (oi1->ip_blkno > oi2->ip_blkno)
> +		mlog_errno(-ENOLCK);
> +
> +	/* lock id1 */
> +	status = ocfs2_inode_lock_nested(inode1, bh1, 1, OI_LS_REFLINK_TARGET);
> +	if (status < 0) {
> +		if (status != -ENOENT)
> +			mlog_errno(status);
> +		goto out_rw2;
> +	}
> +
> +	/* lock id2 */
> +	if (!same_inode) {
> +		status = ocfs2_inode_lock_nested(inode2, bh2, 1,
> +						 OI_LS_REFLINK_TARGET);
> +		if (status < 0) {
> +			if (status != -ENOENT)
> +				mlog_errno(status);
> +			goto out_cl1;
> +		}
> +	} else
> +		*bh2 = *bh1;
> +
> +	trace_ocfs2_double_lock_end(
> +			(unsigned long long)OCFS2_I(inode1)->ip_blkno,
> +			(unsigned long long)OCFS2_I(inode2)->ip_blkno);
> +
> +	return 0;
> +
> +out_cl1:
> +	ocfs2_inode_unlock(inode1, 1);
> +	brelse(*bh1);
> +	*bh1 = NULL;
> +out_rw2:
> +	ocfs2_rw_unlock(inode2, 1);
> +out_i2:
> +	inode_unlock(inode2);
> +	ocfs2_rw_unlock(inode1, 1);
> +out_i1:
> +	inode_unlock(inode1);
> +	return status;
> +}
> +
> +/* Unlock both inodes and release buffers. */
> +static void ocfs2_reflink_inodes_unlock(struct inode *s_inode,
> +					struct buffer_head *s_bh,
> +					struct inode *t_inode,
> +					struct buffer_head *t_bh)
> +{
> +	ocfs2_inode_unlock(s_inode, 1);
> +	ocfs2_rw_unlock(s_inode, 1);
> +	inode_unlock(s_inode);
> +	brelse(s_bh);
> +
> +	if (s_inode == t_inode)
> +		return;
> +
> +	ocfs2_inode_unlock(t_inode, 1);
> +	ocfs2_rw_unlock(t_inode, 1);
> +	inode_unlock(t_inode);
> +	brelse(t_bh);
> +}
> +
> +/*
> + * Read a page's worth of file data into the page cache.  Return the page
> + * locked.
> + */
> +static struct page *ocfs2_reflink_get_page(struct inode *inode,
> +					   loff_t offset)
> +{
> +	struct address_space *mapping;
> +	struct page *page;
> +	pgoff_t n;
> +
> +	n = offset >> PAGE_SHIFT;
> +	mapping = inode->i_mapping;
> +	page = read_mapping_page(mapping, n, NULL);
> +	if (IS_ERR(page))
> +		return page;
> +	if (!PageUptodate(page)) {
> +		put_page(page);
> +		return ERR_PTR(-EIO);
> +	}
> +	lock_page(page);
> +	return page;
> +}
> +
> +/*
> + * Compare extents of two files to see if they are the same.
> + */
> +static int ocfs2_reflink_compare_extents(struct inode *src,
> +					 loff_t srcoff,
> +					 struct inode *dest,
> +					 loff_t destoff,
> +					 loff_t len,
> +					 bool *is_same)
> +{
> +	loff_t src_poff;
> +	loff_t dest_poff;
> +	void *src_addr;
> +	void *dest_addr;
> +	struct page *src_page;
> +	struct page *dest_page;
> +	loff_t cmp_len;
> +	bool same;
> +	int error;
> +
> +	error = -EINVAL;
> +	same = true;
> +	while (len) {
> +		src_poff = srcoff & (PAGE_SIZE - 1);
> +		dest_poff = destoff & (PAGE_SIZE - 1);
> +		cmp_len = min(PAGE_SIZE - src_poff,
> +			      PAGE_SIZE - dest_poff);
> +		cmp_len = min(cmp_len, len);
> +		if (cmp_len <= 0) {
> +			mlog_errno(-EUCLEAN);
> +			goto out_error;
> +		}
> +
> +		src_page = ocfs2_reflink_get_page(src, srcoff);
> +		if (IS_ERR(src_page)) {
> +			error = PTR_ERR(src_page);
> +			goto out_error;
> +		}
> +		dest_page = ocfs2_reflink_get_page(dest, destoff);
> +		if (IS_ERR(dest_page)) {
> +			error = PTR_ERR(dest_page);
> +			unlock_page(src_page);
> +			put_page(src_page);
> +			goto out_error;
> +		}
> +		src_addr = kmap_atomic(src_page);
> +		dest_addr = kmap_atomic(dest_page);
> +
> +		flush_dcache_page(src_page);
> +		flush_dcache_page(dest_page);
> +
> +		if (memcmp(src_addr + src_poff, dest_addr + dest_poff, cmp_len))
> +			same = false;
> +
> +		kunmap_atomic(dest_addr);
> +		kunmap_atomic(src_addr);
> +		unlock_page(dest_page);
> +		unlock_page(src_page);
> +		put_page(dest_page);
> +		put_page(src_page);
> +
> +		if (!same)
> +			break;
> +
> +		srcoff += cmp_len;
> +		destoff += cmp_len;
> +		len -= cmp_len;
> +	}
> +
> +	*is_same = same;
> +	return 0;
> +
> +out_error:
> +	return error;
> +}
> +
> +/* Link a range of blocks from one file to another. */
> +int ocfs2_reflink_remap_range(struct file *file_in,
> +			      loff_t pos_in,
> +			      struct file *file_out,
> +			      loff_t pos_out,
> +			      u64 len,
> +			      bool is_dedupe)
> +{
> +	struct inode *inode_in = file_inode(file_in);
> +	struct inode *inode_out = file_inode(file_out);
> +	struct ocfs2_super *osb = OCFS2_SB(inode_in->i_sb);
> +	struct buffer_head *in_bh = NULL, *out_bh = NULL;
> +	loff_t bs = 1 << OCFS2_SB(inode_in->i_sb)->s_clustersize_bits;
> +	bool same_inode = (inode_in == inode_out);
> +	bool is_same = false;
> +	loff_t isize;
> +	ssize_t ret;
> +	loff_t blen;
> +
> +	if (!ocfs2_refcount_tree(osb))
> +		return -EOPNOTSUPP;
> +	if (ocfs2_is_hard_readonly(osb) || ocfs2_is_soft_readonly(osb))
> +		return -EROFS;
> +
> +	/* Lock both files against IO */
> +	ret = ocfs2_reflink_inodes_lock(inode_in, &in_bh, inode_out, &out_bh);
> +	if (ret)
> +		return ret;
> +
> +	ret = -EINVAL;
> +	if ((OCFS2_I(inode_in)->ip_flags & OCFS2_INODE_SYSTEM_FILE) ||
> +	    (OCFS2_I(inode_out)->ip_flags & OCFS2_INODE_SYSTEM_FILE))
> +		goto out_unlock;
> +
> +	/* Don't touch certain kinds of inodes */
> +	ret = -EPERM;
> +	if (IS_IMMUTABLE(inode_out))
> +		goto out_unlock;
> +
> +	ret = -ETXTBSY;
> +	if (IS_SWAPFILE(inode_in) || IS_SWAPFILE(inode_out))
> +		goto out_unlock;
> +
> +	/* Don't reflink dirs, pipes, sockets... */
> +	ret = -EISDIR;
> +	if (S_ISDIR(inode_in->i_mode) || S_ISDIR(inode_out->i_mode))
> +		goto out_unlock;
> +	ret = -EINVAL;
> +	if (S_ISFIFO(inode_in->i_mode) || S_ISFIFO(inode_out->i_mode))
> +		goto out_unlock;
> +	if (!S_ISREG(inode_in->i_mode) || !S_ISREG(inode_out->i_mode))
> +		goto out_unlock;
> +
> +	/* Are we going all the way to the end? */
> +	isize = i_size_read(inode_in);
> +	if (isize == 0) {
> +		ret = 0;
> +		goto out_unlock;
> +	}
> +
> +	if (len == 0)
> +		len = isize - pos_in;
> +
> +	/* Ensure offsets don't wrap and the input is inside i_size */
> +	if (pos_in + len < pos_in || pos_out + len < pos_out ||
> +	    pos_in + len > isize)
> +		goto out_unlock;
> +
> +	/* Don't allow dedupe past EOF in the dest file */
> +	if (is_dedupe) {
> +		loff_t	disize;
> +
> +		disize = i_size_read(inode_out);
> +		if (pos_out >= disize || pos_out + len > disize)
> +			goto out_unlock;
> +	}
> +
> +	/* If we're linking to EOF, continue to the block boundary. */
> +	if (pos_in + len == isize)
> +		blen = ALIGN(isize, bs) - pos_in;
> +	else
> +		blen = len;
> +
> +	/* Only reflink if we're aligned to block boundaries */
> +	if (!IS_ALIGNED(pos_in, bs) || !IS_ALIGNED(pos_in + blen, bs) ||
> +	    !IS_ALIGNED(pos_out, bs) || !IS_ALIGNED(pos_out + blen, bs))
> +		goto out_unlock;
> +
> +	/* Don't allow overlapped reflink within the same file */
> +	if (same_inode) {
> +		if (pos_out + blen > pos_in && pos_out < pos_in + blen)
> +			goto out_unlock;
> +	}
> +
> +	/* Wait for the completion of any pending IOs on both files */
> +	inode_dio_wait(inode_in);
> +	if (!same_inode)
> +		inode_dio_wait(inode_out);
> +
> +	ret = filemap_write_and_wait_range(inode_in->i_mapping,
> +			pos_in, pos_in + len - 1);
> +	if (ret)
> +		goto out_unlock;
> +
> +	ret = filemap_write_and_wait_range(inode_out->i_mapping,
> +			pos_out, pos_out + len - 1);
> +	if (ret)
> +		goto out_unlock;
> +
> +	/*
> +	 * Check that the extents are the same.
> +	 */
> +	if (is_dedupe) {
> +		ret = ocfs2_reflink_compare_extents(inode_in, pos_in,
> +						    inode_out, pos_out,
> +						    len, &is_same);
> +		if (ret)
> +			goto out_unlock;
> +		if (!is_same) {
> +			ret = -EBADE;
> +			goto out_unlock;
> +		}
> +	}
> +
> +	/* Lock out changes to the allocation maps */
> +	down_write(&OCFS2_I(inode_in)->ip_alloc_sem);
> +	if (!same_inode)
> +		down_write_nested(&OCFS2_I(inode_out)->ip_alloc_sem,
> +				  SINGLE_DEPTH_NESTING);
> +
> +	/*
> +	 * Invalidate the page cache so that we can clear any CoW mappings
> +	 * in the destination file.
> +	 */
> +	truncate_inode_pages_range(&inode_out->i_data, pos_out,
> +				   PAGE_ALIGN(pos_out + len) - 1);
> +
> +	ret = ocfs2_reflink_remap_blocks(inode_in, in_bh, pos_in, inode_out,
> +					 out_bh, pos_out, len);
> +
> +	up_write(&OCFS2_I(inode_in)->ip_alloc_sem);
> +	if (!same_inode)
> +		up_write(&OCFS2_I(inode_out)->ip_alloc_sem);
> +	if (ret) {
> +		mlog_errno(ret);
> +		goto out_unlock;
> +	}
> +
> +	/*
> +	 * Empty the extent map so that we may get the right extent
> +	 * record from the disk.
> +	 */
> +	ocfs2_extent_map_trunc(inode_in, 0);
> +	ocfs2_extent_map_trunc(inode_out, 0);
> +
> +	ret = ocfs2_reflink_update_dest(inode_out, out_bh, pos_out + len);
> +	if (ret) {
> +		mlog_errno(ret);
> +		goto out_unlock;
> +	}
> +
> +	ocfs2_reflink_inodes_unlock(inode_in, in_bh, inode_out, out_bh);
> +	return 0;
> +
> +out_unlock:
> +	ocfs2_reflink_inodes_unlock(inode_in, in_bh, inode_out, out_bh);
> +	return ret;
> +}
> diff --git a/fs/ocfs2/refcounttree.h b/fs/ocfs2/refcounttree.h
> index 553edfb..c023e88 100644
> --- a/fs/ocfs2/refcounttree.h
> +++ b/fs/ocfs2/refcounttree.h
> @@ -117,4 +117,11 @@ int ocfs2_reflink_ioctl(struct inode *inode,
>   			const char __user *oldname,
>   			const char __user *newname,
>   			bool preserve);
> +int ocfs2_reflink_remap_range(struct file *file_in,
> +			      loff_t pos_in,
> +			      struct file *file_out,
> +			      loff_t pos_out,
> +			      u64 len,
> +			      bool is_dedupe);
> +
>   #endif /* OCFS2_REFCOUNTTREE_H */
>
>
> _______________________________________________
> Ocfs2-devel mailing list
> Ocfs2-devel at oss.oracle.com
> https://oss.oracle.com/mailman/listinfo/ocfs2-devel
>




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