пт, 11 мая 2018 г. в 20:32, Omar Sandoval <osan...@osandov.com>:
> On Fri, May 11, 2018 at 06:49:16PM +0200, David Sterba wrote: > > On Fri, May 11, 2018 at 05:25:50PM +0100, Filipe Manana wrote: > > > On Fri, May 11, 2018 at 4:57 PM, David Sterba <dste...@suse.com> 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 <dste...@suse.com> > > > > --- > > > > > > > > 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 <dste...@suse.com> > > 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 <dste...@suse.com> > > --- > > 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); > kcalloc() implies __GFP_ZERO, do we need that here? AFAIK, yes, because: btrfs_cmp_data_free(): ... pg = cmp->src_pages[i]; if (pg) {...} .. And we will catch that, if errors happens in gather_extent_pages(). Thanks. > > 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 > > -- Have a nice day, Timofey. -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
