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Registered in England and Wales under Company Registration No. 3798903 Subject: [PATCH 02/14] hugetlbfs: Implement show_options From: David Howells To: viro@zeniv.linux.org.uk Cc: dhowells@redhat.com, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, Nadia Yvette Chambers Date: Wed, 05 Jul 2017 16:24:18 +0100 Message-ID: <149926825832.20611.919443766042161206.stgit@warthog.procyon.org.uk> In-Reply-To: <149926824154.20611.6104595541055328700.stgit@warthog.procyon.org.uk> References: <149926824154.20611.6104595541055328700.stgit@warthog.procyon.org.uk> User-Agent: StGit/0.17.1-dirty MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.27]); Wed, 05 Jul 2017 15:24:22 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 5166 Lines: 155 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 cc: Nadia Yvette Chambers --- 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)