From: Xavier Roche <xavier.roche@xxxxxxxxxxx> Subject: tmpfs: support for file creation time Various filesystems (including ext4) now support file creation time. This patch adds such support for tmpfs-based filesystems. Note that using shmem_getattr() on other file types than regular requires that shmem_is_huge() check type, to stop incorrect HPAGE_PMD_SIZE blksize. [hughd@xxxxxxxxxx: three tweaks to creation time patch] Link: https://lkml.kernel.org/r/b954973a-b8d1-cab8-63bd-6ea8063de3@xxxxxxxxxx Link: https://lkml.kernel.org/r/20220314211150.GA123458@xavier-xps Link: https://lkml.kernel.org/r/b954973a-b8d1-cab8-63bd-6ea8063de3@xxxxxxxxxx Link: https://lkml.kernel.org/r/20220211213628.GA1919658@xavier-xps Signed-off-by: Xavier Roche <xavier.roche@xxxxxxxxxxx> Signed-off-by: Hugh Dickins <hughd@xxxxxxxxxx> Tested-by: Jean Delvare <jdelvare@xxxxxxx> Tested-by: Sylvain Bellone <sylvain.bellone@xxxxxxxxxxx> Reported-by: Xavier Grand <xavier.grand@xxxxxxxxxxx> Reviewed-by: Jean Delvare <jdelvare@xxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- include/linux/shmem_fs.h | 1 + mm/shmem.c | 16 +++++++++++++--- 2 files changed, 14 insertions(+), 3 deletions(-) --- a/include/linux/shmem_fs.h~tmpfs-support-for-file-creation-time +++ a/include/linux/shmem_fs.h @@ -24,6 +24,7 @@ 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 timespec64 i_crtime; /* file creation time */ struct inode vfs_inode; }; --- a/mm/shmem.c~tmpfs-support-for-file-creation-time +++ a/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) || @@ -1061,6 +1063,12 @@ static int shmem_getattr(struct user_nam if (shmem_is_huge(NULL, inode, 0)) stat->blksize = HPAGE_PMD_SIZE; + 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; + } + return 0; } @@ -1854,9 +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; @@ -2265,6 +2270,7 @@ static struct inode *shmem_get_inode(str atomic_set(&info->stop_eviction, 0); info->seals = F_SEAL_SEAL; info->flags = flags & VM_NORESERVE; + info->i_crtime = inode->i_mtime; INIT_LIST_HEAD(&info->shrinklist); INIT_LIST_HEAD(&info->swaplist); simple_xattrs_init(&info->xattrs); @@ -3196,6 +3202,7 @@ static ssize_t shmem_listxattr(struct de #endif /* CONFIG_TMPFS_XATTR */ static const struct inode_operations shmem_short_symlink_operations = { + .getattr = shmem_getattr, .get_link = simple_get_link, #ifdef CONFIG_TMPFS_XATTR .listxattr = shmem_listxattr, @@ -3203,6 +3210,7 @@ static const struct inode_operations shm }; static const struct inode_operations shmem_symlink_inode_operations = { + .getattr = shmem_getattr, .get_link = shmem_get_link, #ifdef CONFIG_TMPFS_XATTR .listxattr = shmem_listxattr, @@ -3790,6 +3798,7 @@ static const struct inode_operations shm static const struct inode_operations shmem_dir_inode_operations = { #ifdef CONFIG_TMPFS + .getattr = shmem_getattr, .create = shmem_create, .lookup = simple_lookup, .link = shmem_link, @@ -3811,6 +3820,7 @@ static const struct inode_operations shm }; static const struct inode_operations shmem_special_inode_operations = { + .getattr = shmem_getattr, #ifdef CONFIG_TMPFS_XATTR .listxattr = shmem_listxattr, #endif _
