Implement the show_options superblock op for hugetlbfs as part of a bid to
get rid of s_options and generic_show_options() to make it easier to
implement a context-based mount where the mount options can be passed
individually over a file descriptor.
Note that the uid and gid should possibly be displayed relative to the
viewer's user namespace.
Signed-off-by: David Howells <dhowells@xxxxxxxxxx>
cc: Nadia Yvette Chambers <nyc@xxxxxxxxxxxxxx>
---
fs/hugetlbfs/inode.c | 70 ++++++++++++++++++++++++++++++++++++++---------
include/linux/hugetlb.h | 3 ++
2 files changed, 59 insertions(+), 14 deletions(-)
diff --git a/fs/hugetlbfs/inode.c b/fs/hugetlbfs/inode.c
index d44f5456eb9b..99b3b9836575 100644
--- a/fs/hugetlbfs/inode.c
+++ b/fs/hugetlbfs/inode.c
@@ -46,13 +46,13 @@ static const struct inode_operations hugetlbfs_dir_inode_operations;
static const struct inode_operations hugetlbfs_inode_operations;
struct hugetlbfs_config {
- kuid_t uid;
- kgid_t gid;
- umode_t mode;
- long max_hpages;
- long nr_inodes;
- struct hstate *hstate;
- long min_hpages;
+ struct hstate *hstate;
+ long max_hpages;
+ long nr_inodes;
+ long min_hpages;
+ kuid_t uid;
+ kgid_t gid;
+ umode_t mode;
};
struct hugetlbfs_inode_info {
@@ -851,6 +851,46 @@ static int hugetlbfs_migrate_page(struct address_space *mapping,
return MIGRATEPAGE_SUCCESS;
}
+/*
+ * Display the mount options in /proc/mounts.
+ */
+static int hugetlbfs_show_options(struct seq_file *m, struct dentry *root)
+{
+ struct hugetlbfs_sb_info *sbinfo = HUGETLBFS_SB(root->d_sb);
+ struct hugepage_subpool *spool = sbinfo->spool;
+ unsigned long hpage_size = huge_page_size(sbinfo->hstate);
+ unsigned hpage_shift = huge_page_shift(sbinfo->hstate);
+ char mod;
+
+ if (!uid_eq(sbinfo->uid, GLOBAL_ROOT_UID))
+ seq_printf(m, ",uid=%u",
+ from_kuid_munged(&init_user_ns, sbinfo->uid));
+ if (!gid_eq(sbinfo->gid, GLOBAL_ROOT_GID))
+ seq_printf(m, ",gid=%u",
+ from_kgid_munged(&init_user_ns, sbinfo->gid));
+ if (sbinfo->mode != 0755)
+ seq_printf(m, ",mode=%o", sbinfo->mode);
+ if (sbinfo->max_inodes != -1)
+ seq_printf(m, ",nr_inodes=%lu", sbinfo->max_inodes);
+
+ hpage_size /= 1024;
+ mod = 'K';
+ if (hpage_size >= 1024) {
+ hpage_size /= 1024;
+ mod = 'M';
+ }
+ seq_printf(m, ",pagesize=%lu%c", hpage_size, mod);
+ if (spool) {
+ if (spool->max_hpages != -1)
+ seq_printf(m, ",size=%llu",
+ (unsigned long long)spool->max_hpages << hpage_shift);
+ if (spool->min_hpages != -1)
+ seq_printf(m, ",min_size=%llu",
+ (unsigned long long)spool->min_hpages << hpage_shift);
+ }
+ return 0;
+}
+
static int hugetlbfs_statfs(struct dentry *dentry, struct kstatfs *buf)
{
struct hugetlbfs_sb_info *sbinfo = HUGETLBFS_SB(dentry->d_sb);
@@ -1008,19 +1048,19 @@ static const struct super_operations hugetlbfs_ops = {
.evict_inode = hugetlbfs_evict_inode,
.statfs = hugetlbfs_statfs,
.put_super = hugetlbfs_put_super,
- .show_options = generic_show_options,
+ .show_options = hugetlbfs_show_options,
};
-enum { NO_SIZE, SIZE_STD, SIZE_PERCENT };
+enum hugetlbfs_size_type { NO_SIZE, SIZE_STD, SIZE_PERCENT };
/*
* Convert size option passed from command line to number of huge pages
* in the pool specified by hstate. Size option could be in bytes
* (val_type == SIZE_STD) or percentage of the pool (val_type == SIZE_PERCENT).
*/
-static long long
+static long
hugetlbfs_size_to_hpages(struct hstate *h, unsigned long long size_opt,
- int val_type)
+ enum hugetlbfs_size_type val_type)
{
if (val_type == NO_SIZE)
return -1;
@@ -1042,7 +1082,7 @@ hugetlbfs_parse_options(char *options, struct hugetlbfs_config *pconfig)
substring_t args[MAX_OPT_ARGS];
int option;
unsigned long long max_size_opt = 0, min_size_opt = 0;
- int max_val_type = NO_SIZE, min_val_type = NO_SIZE;
+ enum hugetlbfs_size_type max_val_type = NO_SIZE, min_val_type = NO_SIZE;
if (!options)
return 0;
@@ -1156,8 +1196,6 @@ hugetlbfs_fill_super(struct super_block *sb, void *data, int silent)
struct hugetlbfs_config config;
struct hugetlbfs_sb_info *sbinfo;
- save_mount_options(sb, data);
-
config.max_hpages = -1; /* No limit on size by default */
config.nr_inodes = -1; /* No limit on number of inodes by default */
config.uid = current_fsuid();
@@ -1178,6 +1216,10 @@ hugetlbfs_fill_super(struct super_block *sb, void *data, int silent)
sbinfo->max_inodes = config.nr_inodes;
sbinfo->free_inodes = config.nr_inodes;
sbinfo->spool = NULL;
+ sbinfo->uid = config.uid;
+ sbinfo->gid = config.gid;
+ sbinfo->mode = config.mode;
+
/*
* Allocate and initialize subpool if maximum or minimum size is
* specified. Any needed reservations (for minimim size) are taken
diff --git a/include/linux/hugetlb.h b/include/linux/hugetlb.h
index b857fc8cc2ec..3b6eeaad2f77 100644
--- a/include/linux/hugetlb.h
+++ b/include/linux/hugetlb.h
@@ -262,6 +262,9 @@ struct hugetlbfs_sb_info {
spinlock_t stat_lock;
struct hstate *hstate;
struct hugepage_subpool *spool;
+ kuid_t uid;
+ kgid_t gid;
+ umode_t mode;
};
static inline struct hugetlbfs_sb_info *HUGETLBFS_SB(struct super_block *sb)
