From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx2.suse.de ([195.135.220.15]:51206 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934103AbeDXN0i (ORCPT ); Tue, 24 Apr 2018 09:26:38 -0400 Received: from relay2.suse.de (charybdis-ext.suse.de [195.135.220.254]) by mx2.suse.de (Postfix) with ESMTP id C2231AC9E for ; Tue, 24 Apr 2018 13:26:36 +0000 (UTC) Subject: Re: [PATCH 3/3] btrfs: switch types to int when counting eb pages To: David Sterba , linux-btrfs@vger.kernel.org References: <868400eeb4643da5af1e3a76c63e220299a191ee.1524523682.git.dsterba@suse.com> From: Nikolay Borisov Message-ID: <78106b43-78dc-3945-2c81-469ef527edc8@suse.com> Date: Tue, 24 Apr 2018 16:26:36 +0300 MIME-Version: 1.0 In-Reply-To: <868400eeb4643da5af1e3a76c63e220299a191ee.1524523682.git.dsterba@suse.com> Content-Type: text/plain; charset=utf-8 Sender: linux-btrfs-owner@vger.kernel.org List-ID: On 24.04.2018 02:03, David Sterba wrote: > The loops iterating eb pages use unsigned long, that's an overkill as > we know that there are at most 16 pages (64k / 4k), and 4 by default > (with nodesize 16k). > > Signed-off-by: David Sterba Reviewed-by: Nikolay Borisov > --- > fs/btrfs/extent_io.c | 44 ++++++++++++++++++++++---------------------- > fs/btrfs/extent_io.h | 2 +- > 2 files changed, 23 insertions(+), 23 deletions(-) > > diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c > index 0cc5d6ae1876..5bdfdb9c8777 100644 > --- a/fs/btrfs/extent_io.c > +++ b/fs/btrfs/extent_io.c > @@ -2062,7 +2062,7 @@ int repair_eb_io_failure(struct btrfs_fs_info *fs_info, > struct extent_buffer *eb, int mirror_num) > { > u64 start = eb->start; > - unsigned long i, num_pages = num_extent_pages(eb); > + int i, num_pages = num_extent_pages(eb); > int ret = 0; > > if (sb_rdonly(fs_info->sb)) > @@ -3541,7 +3541,7 @@ lock_extent_buffer_for_io(struct extent_buffer *eb, > struct btrfs_fs_info *fs_info, > struct extent_page_data *epd) > { > - unsigned long i, num_pages; > + int i, num_pages; > int flush = 0; > int ret = 0; > > @@ -3715,7 +3715,7 @@ static noinline_for_stack int write_one_eb(struct extent_buffer *eb, > struct extent_io_tree *tree = &BTRFS_I(fs_info->btree_inode)->io_tree; > u64 offset = eb->start; > u32 nritems; > - unsigned long i, num_pages; > + int i, num_pages; > unsigned long start, end; > unsigned int write_flags = wbc_to_write_flags(wbc) | REQ_META; > int ret = 0; > @@ -4648,7 +4648,7 @@ int extent_buffer_under_io(struct extent_buffer *eb) > */ > static void btrfs_release_extent_buffer_page(struct extent_buffer *eb) > { > - unsigned long index; > + int index; > struct page *page; > int mapped = !test_bit(EXTENT_BUFFER_DUMMY, &eb->bflags); > > @@ -4744,10 +4744,10 @@ __alloc_extent_buffer(struct btrfs_fs_info *fs_info, u64 start, > > struct extent_buffer *btrfs_clone_extent_buffer(struct extent_buffer *src) > { > - unsigned long i; > + int i; > struct page *p; > struct extent_buffer *new; > - unsigned long num_pages = num_extent_pages(src); > + int num_pages = num_extent_pages(src); > > new = __alloc_extent_buffer(src->fs_info, src->start, src->len); > if (new == NULL) > @@ -4776,8 +4776,8 @@ struct extent_buffer *__alloc_dummy_extent_buffer(struct btrfs_fs_info *fs_info, > u64 start, unsigned long len) > { > struct extent_buffer *eb; > - unsigned long num_pages; > - unsigned long i; > + int num_pages; > + int i; > > eb = __alloc_extent_buffer(fs_info, start, len); > if (!eb) > @@ -4843,7 +4843,7 @@ static void check_buffer_tree_ref(struct extent_buffer *eb) > static void mark_extent_buffer_accessed(struct extent_buffer *eb, > struct page *accessed) > { > - unsigned long num_pages, i; > + int num_pages, i; > > check_buffer_tree_ref(eb); > > @@ -4944,8 +4944,8 @@ struct extent_buffer *alloc_extent_buffer(struct btrfs_fs_info *fs_info, > u64 start) > { > unsigned long len = fs_info->nodesize; > - unsigned long num_pages; > - unsigned long i; > + int num_pages; > + int i; > unsigned long index = start >> PAGE_SHIFT; > struct extent_buffer *eb; > struct extent_buffer *exists = NULL; > @@ -5160,8 +5160,8 @@ void free_extent_buffer_stale(struct extent_buffer *eb) > > void clear_extent_buffer_dirty(struct extent_buffer *eb) > { > - unsigned long i; > - unsigned long num_pages; > + int i; > + int num_pages; > struct page *page; > > num_pages = num_extent_pages(eb); > @@ -5190,8 +5190,8 @@ void clear_extent_buffer_dirty(struct extent_buffer *eb) > > int set_extent_buffer_dirty(struct extent_buffer *eb) > { > - unsigned long i; > - unsigned long num_pages; > + int i; > + int num_pages; > int was_dirty = 0; > > check_buffer_tree_ref(eb); > @@ -5209,9 +5209,9 @@ int set_extent_buffer_dirty(struct extent_buffer *eb) > > void clear_extent_buffer_uptodate(struct extent_buffer *eb) > { > - unsigned long i; > + int i; > struct page *page; > - unsigned long num_pages; > + int num_pages; > > clear_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags); > num_pages = num_extent_pages(eb); > @@ -5224,9 +5224,9 @@ void clear_extent_buffer_uptodate(struct extent_buffer *eb) > > void set_extent_buffer_uptodate(struct extent_buffer *eb) > { > - unsigned long i; > + int i; > struct page *page; > - unsigned long num_pages; > + int num_pages; > > set_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags); > num_pages = num_extent_pages(eb); > @@ -5239,13 +5239,13 @@ void set_extent_buffer_uptodate(struct extent_buffer *eb) > int read_extent_buffer_pages(struct extent_io_tree *tree, > struct extent_buffer *eb, int wait, int mirror_num) > { > - unsigned long i; > + int i; > struct page *page; > int err; > int ret = 0; > int locked_pages = 0; > int all_uptodate = 1; > - unsigned long num_pages; > + int num_pages; > unsigned long num_reads = 0; > struct bio *bio = NULL; > unsigned long bio_flags = 0; > @@ -5577,7 +5577,7 @@ void copy_extent_buffer_full(struct extent_buffer *dst, > struct extent_buffer *src) > { > int i; > - unsigned num_pages; > + int num_pages; > > ASSERT(dst->len == src->len); > > diff --git a/fs/btrfs/extent_io.h b/fs/btrfs/extent_io.h > index d08abc9d385e..3248553a3aa2 100644 > --- a/fs/btrfs/extent_io.h > +++ b/fs/btrfs/extent_io.h > @@ -452,7 +452,7 @@ int read_extent_buffer_pages(struct extent_io_tree *tree, > int mirror_num); > void wait_on_extent_buffer_writeback(struct extent_buffer *eb); > > -static inline unsigned long num_extent_pages(const struct extent_buffer *eb) > +static inline int num_extent_pages(const struct extent_buffer *eb) > { > return eb->len >> PAGE_SHIFT; > } >