On Fri, May 11, 2018 at 05:25:50PM +0100, Filipe Manana wrote: > On Fri, May 11, 2018 at 4:57 PM, David Sterba <dsterba@xxxxxxxx> wrote: > > The dedupe range is 16 MiB, with 4KiB 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. > > > > Signed-off-by: David Sterba <dsterba@xxxxxxxx> > > --- > > > > This depends on the patches that remove the 16MiB restriction in the > > dedupe ioctl, but contextually can be applied to the current code too. > > > > https://patchwork.kernel.org/patch/10374941/ > > > > fs/btrfs/ioctl.c | 4 ++-- > > 1 file changed, 2 insertions(+), 2 deletions(-) > > > > diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c > > index b572e38b4b64..a7f517009cd7 100644 > > --- a/fs/btrfs/ioctl.c > > +++ b/fs/btrfs/ioctl.c > > @@ -3178,8 +3178,8 @@ 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 = kvzalloc(num_pages, sizeof(struct page *), GFP_KERNEL); > > + cmp.dst_pages = kvzalloc(num_pages, sizeof(struct page *), GFP_KERNEL); > > Kvzalloc should take 2 parameters and not 3. And the right function is kvmalloc_array. > Also, aren't the corresponding kvfree() calls missing? Yes, thanks for catching it. The updated version: From: David Sterba <dsterba@xxxxxxxx> Subject: [PATCH] btrfs: use kvzalloc for EXTENT_SAME temporary data The dedupe range is 16 MiB, with 4KiB 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. Signed-off-by: David Sterba <dsterba@xxxxxxxx> --- 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..4fcfa05ed960 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); + cmp.dst_pages = kvmalloc_array(num_pages, sizeof(struct page *), + GFP_KERNEL); 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; } -- 2.16.2 -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
