Commit f7cd16a5 authored by Xavier Roche's avatar Xavier Roche Committed by Linus Torvalds
Browse files

tmpfs: support for file creation time 

Various filesystems (including ext4) now support file creation time.
This 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@google.com: three tweaks to creation time patch]
  Link: https://lkml.kernel.org/r/b954973a-b8d1-cab8-63bd-6ea8063de3@google.com

Link: https://lkml.kernel.org/r/20220314211150.GA123458@xavier-xps
Link: https://lkml.kernel.org/r/b954973a-b8d1-cab8-63bd-6ea8063de3@google.com
Link: https://lkml.kernel.org/r/20220211213628.GA1919658@xavier-xps


Signed-off-by: default avatarXavier Roche <xavier.roche@algolia.com>
Signed-off-by: default avatarHugh Dickins <hughd@google.com>
Tested-by: default avatarJean Delvare <jdelvare@suse.de>
Tested-by: default avatarSylvain Bellone <sylvain.bellone@algolia.com>
Reported-by: default avatarXavier Grand <xavier.grand@algolia.com>
Reviewed-by: default avatarJean Delvare <jdelvare@suse.de>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 914c32e4

include/linux/shmem_fs.h

+1 −0
Original line number Diff line number Diff line
@@ -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;

};

mm/shmem.c

+13 −3
Original line number Diff line number Diff line
@@ -476,6 +476,8 @@ bool shmem_is_huge(struct vm_area_struct *vma, 
{

	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_namespace *mnt_userns, 
	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 @@ static int shmem_getpage_gfp(struct inode *inode, pgoff_t index, 
		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(struct super_block *sb, const struct inode 
		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 dentry *dentry, char *buffer, size_t size) 
#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 shmem_short_symlink_operations = { 
};



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 shmem_inode_operations = { 


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 shmem_dir_inode_operations = { 
};



static const struct inode_operations shmem_special_inode_operations = {

	.getattr	= shmem_getattr,

#ifdef CONFIG_TMPFS_XATTR

	.listxattr	= shmem_listxattr,

#endif