Re: [PATCH 09/16] huge tmpfs: decide stat.st_blksize by shmem_is_huge()
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From: Yang Shi <hidden>
Date: 2021-07-30 23:41:09
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linux-fsdevel, linux-mm, lkml
On Fri, Jul 30, 2021 at 12:51 AM Hugh Dickins [off-list ref] wrote:
4.18 commit 89fdcd262fd4 ("mm: shmem: make stat.st_blksize return huge
page size if THP is on") added is_huge_enabled() to decide st_blksize:
now that hugeness can be defined per file, that too needs to be replaced
by shmem_is_huge().
Unless they have been fcntl'ed F_HUGEPAGE, this does give a different
answer (No) for small files on a "huge=within_size" mount: but that can
be considered a minor bugfix. And a different answer (No) for unfcntl'ed
files on a "huge=advise" mount: I'm reluctant to complicate it, just to
reproduce the same debatable answer as before.
Signed-off-by: Hugh Dickins <hughd@google.com>Reviewed-by: Yang Shi <redacted>
quoted hunk ↗ jump to hunk
--- mm/shmem.c | 12 +----------- 1 file changed, 1 insertion(+), 11 deletions(-)diff --git a/mm/shmem.c b/mm/shmem.c index 67a4b7a4849b..f50f2ede71da 100644 --- a/mm/shmem.c +++ b/mm/shmem.c@@ -712,15 +712,6 @@ static unsigned long shmem_unused_huge_shrink(struct shmem_sb_info *sbinfo, } #endif /* CONFIG_TRANSPARENT_HUGEPAGE */ -static inline bool is_huge_enabled(struct shmem_sb_info *sbinfo) -{ - if (IS_ENABLED(CONFIG_TRANSPARENT_HUGEPAGE) && - (shmem_huge == SHMEM_HUGE_FORCE || sbinfo->huge) && - shmem_huge != SHMEM_HUGE_DENY) - return true; - return false; -} - /* * Like add_to_page_cache_locked, but error if expected item has gone. */@@ -1101,7 +1092,6 @@ static int shmem_getattr(struct user_namespace *mnt_userns, { struct inode *inode = path->dentry->d_inode; struct shmem_inode_info *info = SHMEM_I(inode); - struct shmem_sb_info *sb_info = SHMEM_SB(inode->i_sb); if (info->alloced - info->swapped != inode->i_mapping->nrpages) { spin_lock_irq(&info->lock);@@ -1110,7 +1100,7 @@ static int shmem_getattr(struct user_namespace *mnt_userns, } generic_fillattr(&init_user_ns, inode, stat); - if (is_huge_enabled(sb_info)) + if (shmem_is_huge(NULL, inode, 0)) stat->blksize = HPAGE_PMD_SIZE; return 0; --2.26.2