| Message ID | 20180517154110.29362-1-dsterba@suse.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On 17.05.2018 18:41, David Sterba wrote: > The dedupe range is 16 MiB, with 4 KiB pages and 8 byte pointers, the > arrays can be 32KiB large. To avoid allocation failures due to > fragmented memory, use the allocation with fallback to vmalloc. > > The arrays are allocated and freed only inside btrfs_extent_same and > reused for all the ranges. > > Signed-off-by: David Sterba <dsterba@suse.com> LGTM: Reviewed-by: Nikolay Borisov <nborisov@suse.com> > --- > > Based on git://github.com/kdave/btrfs-devel.git ext/timofey/dedupe-16mb-limit > > v2: > - use kvmalloc_array > - use __GFP_ZERO, as there's no kvzalloc_array > - check that there are no other frees missed, > see https://patchwork.kernel.org/patch/10374941/ for reference > > fs/btrfs/ioctl.c | 16 +++++++++------- > 1 file changed, 9 insertions(+), 7 deletions(-) > > diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c > index b572e38b4b64..20751829104d 100644 > --- a/fs/btrfs/ioctl.c > +++ b/fs/btrfs/ioctl.c > @@ -3178,12 +3178,13 @@ static int btrfs_extent_same(struct inode *src, u64 loff, u64 olen, > * 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. > */ > - cmp.src_pages = kcalloc(num_pages, sizeof(struct page *), GFP_KERNEL); > - cmp.dst_pages = kcalloc(num_pages, sizeof(struct page *), GFP_KERNEL); > + cmp.src_pages = kvmalloc_array(num_pages, sizeof(struct page *), > + GFP_KERNEL | __GFP_ZERO); > + cmp.dst_pages = kvmalloc_array(num_pages, sizeof(struct page *), > + GFP_KERNEL | __GFP_ZERO); > if (!cmp.src_pages || !cmp.dst_pages) { > - kfree(cmp.src_pages); > - kfree(cmp.dst_pages); > - return -ENOMEM; > + ret = -ENOMEM; > + goto out_free; > } > > if (same_inode) > @@ -3211,8 +3212,9 @@ static int btrfs_extent_same(struct inode *src, u64 loff, u64 olen, > else > btrfs_double_inode_unlock(src, dst); > > - kfree(cmp.src_pages); > - kfree(cmp.dst_pages); > +out_free: > + kvfree(cmp.src_pages); > + kvfree(cmp.dst_pages); > > return ret; > } > -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c index b572e38b4b64..20751829104d 100644 --- a/fs/btrfs/ioctl.c +++ b/fs/btrfs/ioctl.c @@ -3178,12 +3178,13 @@ static int btrfs_extent_same(struct inode *src, u64 loff, u64 olen, * 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. */ - cmp.src_pages = kcalloc(num_pages, sizeof(struct page *), GFP_KERNEL); - cmp.dst_pages = kcalloc(num_pages, sizeof(struct page *), GFP_KERNEL); + cmp.src_pages = kvmalloc_array(num_pages, sizeof(struct page *), + GFP_KERNEL | __GFP_ZERO); + cmp.dst_pages = kvmalloc_array(num_pages, sizeof(struct page *), + GFP_KERNEL | __GFP_ZERO); if (!cmp.src_pages || !cmp.dst_pages) { - kfree(cmp.src_pages); - kfree(cmp.dst_pages); - return -ENOMEM; + ret = -ENOMEM; + goto out_free; } if (same_inode) @@ -3211,8 +3212,9 @@ static int btrfs_extent_same(struct inode *src, u64 loff, u64 olen, else btrfs_double_inode_unlock(src, dst); - kfree(cmp.src_pages); - kfree(cmp.dst_pages); +out_free: + kvfree(cmp.src_pages); + kvfree(cmp.dst_pages); return ret; }
The dedupe range is 16 MiB, with 4 KiB pages and 8 byte pointers, the arrays can be 32KiB large. To avoid allocation failures due to fragmented memory, use the allocation with fallback to vmalloc. The arrays are allocated and freed only inside btrfs_extent_same and reused for all the ranges. Signed-off-by: David Sterba <dsterba@suse.com> --- Based on git://github.com/kdave/btrfs-devel.git ext/timofey/dedupe-16mb-limit v2: - use kvmalloc_array - use __GFP_ZERO, as there's no kvzalloc_array - check that there are no other frees missed, see https://patchwork.kernel.org/patch/10374941/ for reference fs/btrfs/ioctl.c | 16 +++++++++------- 1 file changed, 9 insertions(+), 7 deletions(-)