Linux Btrfs filesystem development
 help / color / mirror / Atom feed
* [PATCH v2] Btrfs: btrfs_dedupe_file_range() ioctl, remove 16MiB restriction
@ 2017-12-13  0:45 Timofey Titovets
  2017-12-13 12:52 ` Timofey Titovets
  0 siblings, 1 reply; 2+ messages in thread
From: Timofey Titovets @ 2017-12-13  0:45 UTC (permalink / raw)
  To: linux-btrfs; +Cc: Timofey Titovets

At now btrfs_dedupe_file_range() restricted to 16MiB range for
limit locking time and memory requirement for dedup ioctl()

For too big input range code silently set range to 16MiB

Let's remove that restriction by do iterating over dedup range.
That's backward compatible and will not change anything for request
less then 16MiB.

Changes:
  v1 -> v2:
    - Refactor btrfs_cmp_data_prepare and btrfs_extent_same
    - Store memory of pages array between iterations
    - Lock inodes once, not on each iteration
    - Small inplace cleanups

Signed-off-by: Timofey Titovets <nefelim4ag@gmail.com>
---
 fs/btrfs/ioctl.c | 160 ++++++++++++++++++++++++++++++++-----------------------
 1 file changed, 94 insertions(+), 66 deletions(-)

diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index d136ff0522e6..b17dcab1bb0c 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -2985,8 +2985,8 @@ static void btrfs_cmp_data_free(struct cmp_pages *cmp)
 			put_page(pg);
 		}
 	}
-	kfree(cmp->src_pages);
-	kfree(cmp->dst_pages);
+
+	cmp->num_pages = 0;
 }
 
 static int btrfs_cmp_data_prepare(struct inode *src, u64 loff,
@@ -2994,41 +2994,22 @@ static int btrfs_cmp_data_prepare(struct inode *src, u64 loff,
 				  u64 len, struct cmp_pages *cmp)
 {
 	int ret;
-	int num_pages = PAGE_ALIGN(len) >> PAGE_SHIFT;
-	struct page **src_pgarr, **dst_pgarr;
-
-	/*
-	 * We must gather up all the pages before we initiate our
-	 * extent locking. We use an array for the page pointers. Size
-	 * of the array is bounded by len, which is in turn bounded by
-	 * BTRFS_MAX_DEDUPE_LEN.
-	 */
-	src_pgarr = kcalloc(num_pages, sizeof(struct page *), GFP_KERNEL);
-	dst_pgarr = kcalloc(num_pages, sizeof(struct page *), GFP_KERNEL);
-	if (!src_pgarr || !dst_pgarr) {
-		kfree(src_pgarr);
-		kfree(dst_pgarr);
-		return -ENOMEM;
-	}
-	cmp->num_pages = num_pages;
-	cmp->src_pages = src_pgarr;
-	cmp->dst_pages = dst_pgarr;
 
 	/*
 	 * If deduping ranges in the same inode, locking rules make it mandatory
 	 * to always lock pages in ascending order to avoid deadlocks with
 	 * concurrent tasks (such as starting writeback/delalloc).
 	 */
-	if (src == dst && dst_loff < loff) {
-		swap(src_pgarr, dst_pgarr);
+	if (src == dst && dst_loff < loff)
 		swap(loff, dst_loff);
-	}
 
-	ret = gather_extent_pages(src, src_pgarr, cmp->num_pages, loff);
+	cmp->num_pages = PAGE_ALIGN(len) >> PAGE_SHIFT;
+
+	ret = gather_extent_pages(src, cmp->src_pages, cmp->num_pages, loff);
 	if (ret)
 		goto out;
 
-	ret = gather_extent_pages(dst, dst_pgarr, cmp->num_pages, dst_loff);
+	ret = gather_extent_pages(dst, cmp->dst_pages, cmp->num_pages, dst_loff);
 
 out:
 	if (ret)
@@ -3098,31 +3079,23 @@ static int extent_same_check_offsets(struct inode *inode, u64 off, u64 *plen,
 	return 0;
 }
 
-static int btrfs_extent_same(struct inode *src, u64 loff, u64 olen,
-			     struct inode *dst, u64 dst_loff)
+static int __btrfs_extent_same(struct inode *src, u64 loff, u64 olen,
+			       struct inode *dst, u64 dst_loff,
+			       struct cmp_pages *cmp)
 {
 	int ret;
 	u64 len = olen;
-	struct cmp_pages cmp;
 	bool same_inode = (src == dst);
 	u64 same_lock_start = 0;
 	u64 same_lock_len = 0;
 
-	if (len == 0)
-		return 0;
-
-	if (same_inode)
-		inode_lock(src);
-	else
-		btrfs_double_inode_lock(src, dst);
-
 	ret = extent_same_check_offsets(src, loff, &len, olen);
 	if (ret)
-		goto out_unlock;
+		return ret;
 
 	ret = extent_same_check_offsets(dst, dst_loff, &len, olen);
 	if (ret)
-		goto out_unlock;
+		return ret;
 
 	if (same_inode) {
 		/*
@@ -3139,32 +3112,21 @@ static int btrfs_extent_same(struct inode *src, u64 loff, u64 olen,
 		 * allow an unaligned length so long as it ends at
 		 * i_size.
 		 */
-		if (len != olen) {
-			ret = -EINVAL;
-			goto out_unlock;
-		}
+		if (len != olen)
+			return -EINVAL;
 
 		/* Check for overlapping ranges */
-		if (dst_loff + len > loff && dst_loff < loff + len) {
-			ret = -EINVAL;
-			goto out_unlock;
-		}
+		if (dst_loff + len > loff && dst_loff < loff + len)
+			return -EINVAL;
 
 		same_lock_start = min_t(u64, loff, dst_loff);
 		same_lock_len = max_t(u64, loff, dst_loff) + len - same_lock_start;
 	}
 
-	/* don't make the dst file partly checksummed */
-	if ((BTRFS_I(src)->flags & BTRFS_INODE_NODATASUM) !=
-	    (BTRFS_I(dst)->flags & BTRFS_INODE_NODATASUM)) {
-		ret = -EINVAL;
-		goto out_unlock;
-	}
-
 again:
-	ret = btrfs_cmp_data_prepare(src, loff, dst, dst_loff, olen, &cmp);
+	ret = btrfs_cmp_data_prepare(src, loff, dst, dst_loff, olen, cmp);
 	if (ret)
-		goto out_unlock;
+		return ret;
 
 	if (same_inode)
 		ret = lock_extent_range(src, same_lock_start, same_lock_len,
@@ -3185,7 +3147,7 @@ static int btrfs_extent_same(struct inode *src, u64 loff, u64 olen,
 		 * Ranges in the io trees already unlocked. Now unlock all
 		 * pages before waiting for all IO to complete.
 		 */
-		btrfs_cmp_data_free(&cmp);
+		btrfs_cmp_data_free(cmp);
 		if (same_inode) {
 			btrfs_wait_ordered_range(src, same_lock_start,
 						 same_lock_len);
@@ -3198,12 +3160,12 @@ static int btrfs_extent_same(struct inode *src, u64 loff, u64 olen,
 	ASSERT(ret == 0);
 	if (WARN_ON(ret)) {
 		/* ranges in the io trees already unlocked */
-		btrfs_cmp_data_free(&cmp);
+		btrfs_cmp_data_free(cmp);
 		return ret;
 	}
 
 	/* pass original length for comparison so we stay within i_size */
-	ret = btrfs_cmp_data(olen, &cmp);
+	ret = btrfs_cmp_data(olen, cmp);
 	if (ret == 0)
 		ret = btrfs_clone(src, dst, loff, olen, len, dst_loff, 1);
 
@@ -3213,8 +3175,79 @@ static int btrfs_extent_same(struct inode *src, u64 loff, u64 olen,
 	else
 		btrfs_double_extent_unlock(src, loff, dst, dst_loff, len);
 
-	btrfs_cmp_data_free(&cmp);
-out_unlock:
+	btrfs_cmp_data_free(cmp);
+
+	return ret;
+}
+
+#define BTRFS_MAX_DEDUPE_LEN	SZ_16M
+
+static int btrfs_extent_same(struct inode *src, u64 loff, u64 olen,
+				 struct inode *dst, u64 dst_loff)
+{
+	int ret;
+	int num_pages;
+	bool same_inode = (src == dst);
+	u64 i, tail_len, chunk_count;
+	struct cmp_pages cmp;
+
+	if (olen == 0)
+		return 0;
+
+	/* don't make the dst file partly checksummed */
+	if ((BTRFS_I(src)->flags & BTRFS_INODE_NODATASUM) !=
+	    (BTRFS_I(dst)->flags & BTRFS_INODE_NODATASUM)) {
+		return -EINVAL;
+	}
+
+	if (same_inode)
+		inode_lock(src);
+	else
+		btrfs_double_inode_lock(src, dst);
+
+	tail_len = olen % BTRFS_MAX_DEDUPE_LEN;
+	chunk_count = div_u64(olen, BTRFS_MAX_DEDUPE_LEN);
+
+	if (chunk_count > 0) {
+		num_pages = PAGE_ALIGN(BTRFS_MAX_DEDUPE_LEN) >> PAGE_SHIFT;
+	} else {
+		num_pages = PAGE_ALIGN(tail_len) >> PAGE_SHIFT;
+	}
+	/*
+	 * We must gather up all the pages before we initiate our
+	 * extent locking. We use an array for the page pointers. Size
+	 * of the array is bounded by len, which is in turn bounded by
+	 * BTRFS_MAX_DEDUPE_LEN.
+	 */
+	ret = -ENOMEM;
+	cmp.src_pages = kcalloc(num_pages, sizeof(struct page *),
+				GFP_KERNEL);
+	if (!cmp.src_pages)
+		goto out;
+	cmp.dst_pages = kcalloc(num_pages, sizeof(struct page *),
+				GFP_KERNEL);
+	if (!cmp.dst_pages)
+		goto out;
+
+
+	for (i = 0; i < chunk_count; i++) {
+		ret = __btrfs_extent_same(src, loff, BTRFS_MAX_DEDUPE_LEN,
+					  dst, dst_loff, &cmp);
+		if (ret)
+			goto out;
+
+		loff += BTRFS_MAX_DEDUPE_LEN;
+		dst_loff += BTRFS_MAX_DEDUPE_LEN;
+	}
+
+	if (tail_len > 0)
+		ret = __btrfs_extent_same(src, loff, tail_len,
+					  dst, dst_loff, &cmp);
+
+out:
+	kfree(cmp.src_pages);
+	kfree(cmp.dst_pages);
+
 	if (same_inode)
 		inode_unlock(src);
 	else
@@ -3223,8 +3256,6 @@ static int btrfs_extent_same(struct inode *src, u64 loff, u64 olen,
 	return ret;
 }
 
-#define BTRFS_MAX_DEDUPE_LEN	SZ_16M
-
 ssize_t btrfs_dedupe_file_range(struct file *src_file, u64 loff, u64 olen,
 				struct file *dst_file, u64 dst_loff)
 {
@@ -3233,9 +3264,6 @@ ssize_t btrfs_dedupe_file_range(struct file *src_file, u64 loff, u64 olen,
 	u64 bs = BTRFS_I(src)->root->fs_info->sb->s_blocksize;
 	ssize_t res;
 
-	if (olen > BTRFS_MAX_DEDUPE_LEN)
-		olen = BTRFS_MAX_DEDUPE_LEN;
-
 	if (WARN_ON_ONCE(bs < PAGE_SIZE)) {
 		/*
 		 * Btrfs does not support blocksize < page_size. As a
-- 
2.15.1

^ permalink raw reply related	[flat|nested] 2+ messages in thread

* Re: [PATCH v2] Btrfs: btrfs_dedupe_file_range() ioctl, remove 16MiB restriction
  2017-12-13  0:45 [PATCH v2] Btrfs: btrfs_dedupe_file_range() ioctl, remove 16MiB restriction Timofey Titovets
@ 2017-12-13 12:52 ` Timofey Titovets
  0 siblings, 0 replies; 2+ messages in thread
From: Timofey Titovets @ 2017-12-13 12:52 UTC (permalink / raw)
  To: linux-btrfs; +Cc: Timofey Titovets

Compile tested && battle tested by btrfs-extent-same from duperemove.

At performance, i see a negligible difference.

Thanks

2017-12-13 3:45 GMT+03:00 Timofey Titovets <nefelim4ag@gmail.com>:
> At now btrfs_dedupe_file_range() restricted to 16MiB range for
> limit locking time and memory requirement for dedup ioctl()
>
> For too big input range code silently set range to 16MiB
>
> Let's remove that restriction by do iterating over dedup range.
> That's backward compatible and will not change anything for request
> less then 16MiB.
>
> Changes:
>   v1 -> v2:
>     - Refactor btrfs_cmp_data_prepare and btrfs_extent_same
>     - Store memory of pages array between iterations
>     - Lock inodes once, not on each iteration
>     - Small inplace cleanups
>
> Signed-off-by: Timofey Titovets <nefelim4ag@gmail.com>
> ---
>  fs/btrfs/ioctl.c | 160 ++++++++++++++++++++++++++++++++-----------------------
>  1 file changed, 94 insertions(+), 66 deletions(-)
>
> diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
> index d136ff0522e6..b17dcab1bb0c 100644
> --- a/fs/btrfs/ioctl.c
> +++ b/fs/btrfs/ioctl.c
> @@ -2985,8 +2985,8 @@ static void btrfs_cmp_data_free(struct cmp_pages *cmp)
>                         put_page(pg);
>                 }
>         }
> -       kfree(cmp->src_pages);
> -       kfree(cmp->dst_pages);
> +
> +       cmp->num_pages = 0;
>  }
>
>  static int btrfs_cmp_data_prepare(struct inode *src, u64 loff,
> @@ -2994,41 +2994,22 @@ static int btrfs_cmp_data_prepare(struct inode *src, u64 loff,
>                                   u64 len, struct cmp_pages *cmp)
>  {
>         int ret;
> -       int num_pages = PAGE_ALIGN(len) >> PAGE_SHIFT;
> -       struct page **src_pgarr, **dst_pgarr;
> -
> -       /*
> -        * We must gather up all the pages before we initiate our
> -        * extent locking. We use an array for the page pointers. Size
> -        * of the array is bounded by len, which is in turn bounded by
> -        * BTRFS_MAX_DEDUPE_LEN.
> -        */
> -       src_pgarr = kcalloc(num_pages, sizeof(struct page *), GFP_KERNEL);
> -       dst_pgarr = kcalloc(num_pages, sizeof(struct page *), GFP_KERNEL);
> -       if (!src_pgarr || !dst_pgarr) {
> -               kfree(src_pgarr);
> -               kfree(dst_pgarr);
> -               return -ENOMEM;
> -       }
> -       cmp->num_pages = num_pages;
> -       cmp->src_pages = src_pgarr;
> -       cmp->dst_pages = dst_pgarr;
>
>         /*
>          * If deduping ranges in the same inode, locking rules make it mandatory
>          * to always lock pages in ascending order to avoid deadlocks with
>          * concurrent tasks (such as starting writeback/delalloc).
>          */
> -       if (src == dst && dst_loff < loff) {
> -               swap(src_pgarr, dst_pgarr);
> +       if (src == dst && dst_loff < loff)
>                 swap(loff, dst_loff);
> -       }
>
> -       ret = gather_extent_pages(src, src_pgarr, cmp->num_pages, loff);
> +       cmp->num_pages = PAGE_ALIGN(len) >> PAGE_SHIFT;
> +
> +       ret = gather_extent_pages(src, cmp->src_pages, cmp->num_pages, loff);
>         if (ret)
>                 goto out;
>
> -       ret = gather_extent_pages(dst, dst_pgarr, cmp->num_pages, dst_loff);
> +       ret = gather_extent_pages(dst, cmp->dst_pages, cmp->num_pages, dst_loff);
>
>  out:
>         if (ret)
> @@ -3098,31 +3079,23 @@ static int extent_same_check_offsets(struct inode *inode, u64 off, u64 *plen,
>         return 0;
>  }
>
> -static int btrfs_extent_same(struct inode *src, u64 loff, u64 olen,
> -                            struct inode *dst, u64 dst_loff)
> +static int __btrfs_extent_same(struct inode *src, u64 loff, u64 olen,
> +                              struct inode *dst, u64 dst_loff,
> +                              struct cmp_pages *cmp)
>  {
>         int ret;
>         u64 len = olen;
> -       struct cmp_pages cmp;
>         bool same_inode = (src == dst);
>         u64 same_lock_start = 0;
>         u64 same_lock_len = 0;
>
> -       if (len == 0)
> -               return 0;
> -
> -       if (same_inode)
> -               inode_lock(src);
> -       else
> -               btrfs_double_inode_lock(src, dst);
> -
>         ret = extent_same_check_offsets(src, loff, &len, olen);
>         if (ret)
> -               goto out_unlock;
> +               return ret;
>
>         ret = extent_same_check_offsets(dst, dst_loff, &len, olen);
>         if (ret)
> -               goto out_unlock;
> +               return ret;
>
>         if (same_inode) {
>                 /*
> @@ -3139,32 +3112,21 @@ static int btrfs_extent_same(struct inode *src, u64 loff, u64 olen,
>                  * allow an unaligned length so long as it ends at
>                  * i_size.
>                  */
> -               if (len != olen) {
> -                       ret = -EINVAL;
> -                       goto out_unlock;
> -               }
> +               if (len != olen)
> +                       return -EINVAL;
>
>                 /* Check for overlapping ranges */
> -               if (dst_loff + len > loff && dst_loff < loff + len) {
> -                       ret = -EINVAL;
> -                       goto out_unlock;
> -               }
> +               if (dst_loff + len > loff && dst_loff < loff + len)
> +                       return -EINVAL;
>
>                 same_lock_start = min_t(u64, loff, dst_loff);
>                 same_lock_len = max_t(u64, loff, dst_loff) + len - same_lock_start;
>         }
>
> -       /* don't make the dst file partly checksummed */
> -       if ((BTRFS_I(src)->flags & BTRFS_INODE_NODATASUM) !=
> -           (BTRFS_I(dst)->flags & BTRFS_INODE_NODATASUM)) {
> -               ret = -EINVAL;
> -               goto out_unlock;
> -       }
> -
>  again:
> -       ret = btrfs_cmp_data_prepare(src, loff, dst, dst_loff, olen, &cmp);
> +       ret = btrfs_cmp_data_prepare(src, loff, dst, dst_loff, olen, cmp);
>         if (ret)
> -               goto out_unlock;
> +               return ret;
>
>         if (same_inode)
>                 ret = lock_extent_range(src, same_lock_start, same_lock_len,
> @@ -3185,7 +3147,7 @@ static int btrfs_extent_same(struct inode *src, u64 loff, u64 olen,
>                  * Ranges in the io trees already unlocked. Now unlock all
>                  * pages before waiting for all IO to complete.
>                  */
> -               btrfs_cmp_data_free(&cmp);
> +               btrfs_cmp_data_free(cmp);
>                 if (same_inode) {
>                         btrfs_wait_ordered_range(src, same_lock_start,
>                                                  same_lock_len);
> @@ -3198,12 +3160,12 @@ static int btrfs_extent_same(struct inode *src, u64 loff, u64 olen,
>         ASSERT(ret == 0);
>         if (WARN_ON(ret)) {
>                 /* ranges in the io trees already unlocked */
> -               btrfs_cmp_data_free(&cmp);
> +               btrfs_cmp_data_free(cmp);
>                 return ret;
>         }
>
>         /* pass original length for comparison so we stay within i_size */
> -       ret = btrfs_cmp_data(olen, &cmp);
> +       ret = btrfs_cmp_data(olen, cmp);
>         if (ret == 0)
>                 ret = btrfs_clone(src, dst, loff, olen, len, dst_loff, 1);
>
> @@ -3213,8 +3175,79 @@ static int btrfs_extent_same(struct inode *src, u64 loff, u64 olen,
>         else
>                 btrfs_double_extent_unlock(src, loff, dst, dst_loff, len);
>
> -       btrfs_cmp_data_free(&cmp);
> -out_unlock:
> +       btrfs_cmp_data_free(cmp);
> +
> +       return ret;
> +}
> +
> +#define BTRFS_MAX_DEDUPE_LEN   SZ_16M
> +
> +static int btrfs_extent_same(struct inode *src, u64 loff, u64 olen,
> +                                struct inode *dst, u64 dst_loff)
> +{
> +       int ret;
> +       int num_pages;
> +       bool same_inode = (src == dst);
> +       u64 i, tail_len, chunk_count;
> +       struct cmp_pages cmp;
> +
> +       if (olen == 0)
> +               return 0;
> +
> +       /* don't make the dst file partly checksummed */
> +       if ((BTRFS_I(src)->flags & BTRFS_INODE_NODATASUM) !=
> +           (BTRFS_I(dst)->flags & BTRFS_INODE_NODATASUM)) {
> +               return -EINVAL;
> +       }
> +
> +       if (same_inode)
> +               inode_lock(src);
> +       else
> +               btrfs_double_inode_lock(src, dst);
> +
> +       tail_len = olen % BTRFS_MAX_DEDUPE_LEN;
> +       chunk_count = div_u64(olen, BTRFS_MAX_DEDUPE_LEN);
> +
> +       if (chunk_count > 0) {
> +               num_pages = PAGE_ALIGN(BTRFS_MAX_DEDUPE_LEN) >> PAGE_SHIFT;
> +       } else {
> +               num_pages = PAGE_ALIGN(tail_len) >> PAGE_SHIFT;
> +       }
> +       /*
> +        * We must gather up all the pages before we initiate our
> +        * extent locking. We use an array for the page pointers. Size
> +        * of the array is bounded by len, which is in turn bounded by
> +        * BTRFS_MAX_DEDUPE_LEN.
> +        */
> +       ret = -ENOMEM;
> +       cmp.src_pages = kcalloc(num_pages, sizeof(struct page *),
> +                               GFP_KERNEL);
> +       if (!cmp.src_pages)
> +               goto out;
> +       cmp.dst_pages = kcalloc(num_pages, sizeof(struct page *),
> +                               GFP_KERNEL);
> +       if (!cmp.dst_pages)
> +               goto out;
> +
> +
> +       for (i = 0; i < chunk_count; i++) {
> +               ret = __btrfs_extent_same(src, loff, BTRFS_MAX_DEDUPE_LEN,
> +                                         dst, dst_loff, &cmp);
> +               if (ret)
> +                       goto out;
> +
> +               loff += BTRFS_MAX_DEDUPE_LEN;
> +               dst_loff += BTRFS_MAX_DEDUPE_LEN;
> +       }
> +
> +       if (tail_len > 0)
> +               ret = __btrfs_extent_same(src, loff, tail_len,
> +                                         dst, dst_loff, &cmp);
> +
> +out:
> +       kfree(cmp.src_pages);
> +       kfree(cmp.dst_pages);
> +
>         if (same_inode)
>                 inode_unlock(src);
>         else
> @@ -3223,8 +3256,6 @@ static int btrfs_extent_same(struct inode *src, u64 loff, u64 olen,
>         return ret;
>  }
>
> -#define BTRFS_MAX_DEDUPE_LEN   SZ_16M
> -
>  ssize_t btrfs_dedupe_file_range(struct file *src_file, u64 loff, u64 olen,
>                                 struct file *dst_file, u64 dst_loff)
>  {
> @@ -3233,9 +3264,6 @@ ssize_t btrfs_dedupe_file_range(struct file *src_file, u64 loff, u64 olen,
>         u64 bs = BTRFS_I(src)->root->fs_info->sb->s_blocksize;
>         ssize_t res;
>
> -       if (olen > BTRFS_MAX_DEDUPE_LEN)
> -               olen = BTRFS_MAX_DEDUPE_LEN;
> -
>         if (WARN_ON_ONCE(bs < PAGE_SIZE)) {
>                 /*
>                  * Btrfs does not support blocksize < page_size. As a
> --
> 2.15.1



-- 
Have a nice day,
Timofey.

^ permalink raw reply	[flat|nested] 2+ messages in thread

end of thread, other threads:[~2017-12-13 12:53 UTC | newest]

Thread overview: 2+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2017-12-13  0:45 [PATCH v2] Btrfs: btrfs_dedupe_file_range() ioctl, remove 16MiB restriction Timofey Titovets
2017-12-13 12:52 ` Timofey Titovets

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox