[PATCH mmotm] tmpfs: three tweaks to creation time patch

Hugh Dickins
2022-02-27T06:31:47Z

Thank you to Xavier Roche for his tmpfs file creation time patch.
Please apply these 3 tweaks on top (and fold in when sending to Linus):

1. Move vfs_inode back to being last element of shmem_inode_info.
2. Remove unnecessary parentheses from condition in shmem_getattr().
3. Using shmem_getattr() on other file types than regular requires that
shmem_is_huge() check type, to stop incorrect HPAGE_PMD_SIZE blksize.

Signed-off-by: Hugh Dickins <hughd@google.com>
---
Cleanups and fix to tmpfs-support-for-file-creation-time.patch

include/linux/shmem_fs.h | 2 +-
mm/shmem.c | 7 +++----
2 files changed, 4 insertions(+), 5 deletions(-)

--- mmotm/include/linux/shmem_fs.h
+++ linux/include/linux/shmem_fs.h
@@ -24,8 +24,8 @@ struct shmem_inode_info {
struct shared_policy policy; /* NUMA memory alloc policy */
struct simple_xattrs xattrs; /* list of xattrs */
atomic_t stop_eviction; /* hold when working on inode */
- struct inode vfs_inode;
struct timespec64 i_crtime; /* file creation time */
+ struct inode vfs_inode;
};

struct shmem_sb_info {
--- mmotm/mm/shmem.c
+++ linux/mm/shmem.c
@@ -476,6 +476,8 @@ bool shmem_is_huge(struct vm_area_struct
{
loff_t i_size;

+ if (!S_ISREG(inode->i_mode))
+ return false;
if (shmem_huge == SHMEM_HUGE_DENY)
return false;
if (vma && ((vma->vm_flags & VM_NOHUGEPAGE) ||
@@ -1061,7 +1063,7 @@ static int shmem_getattr(struct user_nam
if (shmem_is_huge(NULL, inode, 0))
stat->blksize = HPAGE_PMD_SIZE;

- if ((request_mask & STATX_BTIME)) {
+ if (request_mask & STATX_BTIME) {
stat->result_mask |= STATX_BTIME;
stat->btime.tv_sec = info->i_crtime.tv_sec;
stat->btime.tv_nsec = info->i_crtime.tv_nsec;
@@ -1860,9 +1862,6 @@ repeat:
return 0;
}

- /* Never use a huge page for shmem_symlink() */
- if (S_ISLNK(inode->i_mode))
- goto alloc_nohuge;
if (!shmem_is_huge(vma, inode, index))
goto alloc_nohuge;