On Fri, May 11, 2018 at 5:49 PM, David Sterba <dste...@suse.cz> 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); > 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);
kvfree() missing at btrfs_cmp_data_free() too. > > return ret; > } > -- > 2.16.2 > -- Filipe David Manana, “Whether you think you can, or you think you can't — you're right.” -- 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
