[PATCH 1/3] tmpfs: add project ID support

[cem@kernel.org]

From: Carlos Maiolino <cem@kernel.org>

Lay down infrastructure to support project quotas.

Signed-off-by: Carlos Maiolino <cmaiolino@redhat.com>
---
 include/linux/shmem_fs.h | 11 ++++++++---
 mm/shmem.c               |  6 ++++++
 mm/shmem_quota.c         | 10 ++++++++++
 3 files changed, 24 insertions(+), 3 deletions(-)

diff --git a/include/linux/shmem_fs.h b/include/linux/shmem_fs.h
index 6b0c626620f5..e82a64f97917 100644
--- a/include/linux/shmem_fs.h
+++ b/include/linux/shmem_fs.h
@@ -15,7 +15,10 @@
 
 #ifdef CONFIG_TMPFS_QUOTA
 #define SHMEM_MAXQUOTAS 2
-#endif
+
+/* Default project ID */
+#define SHMEM_DEF_PROJID 0
+#endif /* CONFIG_TMPFS_QUOTA */
 
 struct shmem_inode_info {
 	spinlock_t		lock;
@@ -33,14 +36,16 @@ struct shmem_inode_info {
 	unsigned int		fsflags;	/* flags for FS_IOC_[SG]ETFLAGS */
 #ifdef CONFIG_TMPFS_QUOTA
 	struct dquot		*i_dquot[MAXQUOTAS];
+	kprojid_t		i_projid;
 #endif
 	struct offset_ctx	dir_offsets;	/* stable entry offsets */
 	struct inode		vfs_inode;
 };
 
-#define SHMEM_FL_USER_VISIBLE		FS_FL_USER_VISIBLE
+#define SHMEM_FL_USER_VISIBLE		(FS_FL_USER_VISIBLE | FS_PROJINHERIT_FL)
 #define SHMEM_FL_USER_MODIFIABLE \
-	(FS_IMMUTABLE_FL | FS_APPEND_FL | FS_NODUMP_FL | FS_NOATIME_FL)
+	(FS_IMMUTABLE_FL | FS_APPEND_FL | FS_NODUMP_FL | \
+	 FS_NOATIME_FL | FS_PROJINHERIT_FL)
 #define SHMEM_FL_INHERITED		(FS_NODUMP_FL | FS_NOATIME_FL)
 
 struct shmem_quota_limits {
diff --git a/mm/shmem.c b/mm/shmem.c
index 67d93dd37a5e..6ccf60bd1690 100644
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -2539,6 +2539,12 @@ static struct inode *shmem_get_inode(struct mnt_idmap *idmap,
 	if (IS_ERR(inode))
 		return inode;
 
+	if (dir && sb_has_quota_active(sb, PRJQUOTA))
+		SHMEM_I(inode)->i_projid = SHMEM_I(dir)->i_projid;
+	else
+		SHMEM_I(inode)->i_projid = make_kprojid(&init_user_ns,
+							SHMEM_DEF_PROJID);
+
 	err = dquot_initialize(inode);
 	if (err)
 		goto errout;
diff --git a/mm/shmem_quota.c b/mm/shmem_quota.c
index 062d1c1097ae..71224caa3e85 100644
--- a/mm/shmem_quota.c
+++ b/mm/shmem_quota.c
@@ -325,6 +325,15 @@ static int shmem_dquot_write_info(struct super_block *sb, int type)
 	return 0;
 }
 
+static int shmem_get_projid(struct inode *inode, kprojid_t *projid)
+{
+	if (!sb_has_quota_active(inode->i_sb, PRJQUOTA))
+		return -EOPNOTSUPP;
+
+	*projid = SHMEM_I(inode)->i_projid;
+	return 0;
+}
+
 static const struct quota_format_ops shmem_format_ops = {
 	.check_quota_file	= shmem_check_quota_file,
 	.read_file_info		= shmem_read_file_info,
@@ -346,5 +355,6 @@ const struct dquot_operations shmem_quota_operations = {
 	.write_info		= shmem_dquot_write_info,
 	.mark_dirty		= shmem_mark_dquot_dirty,
 	.get_next_id		= shmem_get_next_id,
+	.get_projid		= shmem_get_projid,
 };
 #endif /* CONFIG_TMPFS_QUOTA */
-- 
2.39.2