From efffb803bf37d4514e025e3d59e067dabb59bcd1 Mon Sep 17 00:00:00 2001 From: Qu Wenruo Date: Mon, 5 Aug 2024 15:02:54 +0930 Subject: [PATCH] btrfs: make btrfs_is_subpage() to return false directly for 4K page size Btrfs only supports sectorsize 4K, 8K, 16K, 32K, 64K for now, thus for systems with 4K page size, there is no way the fs is subpage (sectorsize < PAGE_SIZE). So here we define btrfs_is_subpage() different according to the PAGE_SIZE: - PAGE_SIZE > 4K We may hit real subpage cases, define btrfs_is_subpage() as a regular function and do the usual checks. - PAGE_SIZE == 4K (no smaller PAGE_SIZE support AFAIK) There is no way the fs is subpage, so just define btrfs_is_subpage() as an inline function which always return false. This saves about 7K bytes for x86_64 debug builds: text data bss dec hex filename Before: 1484452 168693 25776 1678921 199e49 fs/btrfs/btrfs.ko After: 1476605 168445 25776 1670826 197eaa fs/btrfs/btrfs.ko Signed-off-by: Qu Wenruo Reviewed-by: David Sterba Signed-off-by: David Sterba --- fs/btrfs/subpage.c | 2 ++ fs/btrfs/subpage.h | 9 +++++++++ 2 files changed, 11 insertions(+) diff --git a/fs/btrfs/subpage.c b/fs/btrfs/subpage.c index 8ddd5fcbeb93..631d96f1e905 100644 --- a/fs/btrfs/subpage.c +++ b/fs/btrfs/subpage.c @@ -64,6 +64,7 @@ * This means a slightly higher tree locking latency. */ +#if PAGE_SIZE > SZ_4K bool btrfs_is_subpage(const struct btrfs_fs_info *fs_info, struct address_space *mapping) { if (fs_info->sectorsize >= PAGE_SIZE) @@ -85,6 +86,7 @@ bool btrfs_is_subpage(const struct btrfs_fs_info *fs_info, struct address_space return true; return false; } +#endif void btrfs_init_subpage_info(struct btrfs_subpage_info *subpage_info, u32 sectorsize) { diff --git a/fs/btrfs/subpage.h b/fs/btrfs/subpage.h index 249396e118d0..5532cc4fac50 100644 --- a/fs/btrfs/subpage.h +++ b/fs/btrfs/subpage.h @@ -5,6 +5,7 @@ #include #include +#include struct address_space; struct folio; @@ -88,7 +89,15 @@ enum btrfs_subpage_type { BTRFS_SUBPAGE_DATA, }; +#if PAGE_SIZE > SZ_4K bool btrfs_is_subpage(const struct btrfs_fs_info *fs_info, struct address_space *mapping); +#else +static inline bool btrfs_is_subpage(const struct btrfs_fs_info *fs_info, + struct address_space *mapping) +{ + return false; +} +#endif void btrfs_init_subpage_info(struct btrfs_subpage_info *subpage_info, u32 sectorsize); int btrfs_attach_subpage(const struct btrfs_fs_info *fs_info,