[PATCH 22/38] hugetlbfs: Convert to fs_context [ver #10]

David Howells
2018-07-27T17:33:57Z

Convert the hugetlbfs to use the fs_context during mount.

Signed-off-by: David Howells <dhowells@redhat.com>
---

fs/hugetlbfs/inode.c | 392 ++++++++++++++++++++++++++++++--------------------
1 file changed, 232 insertions(+), 160 deletions(-)

diff --git a/fs/hugetlbfs/inode.c b/fs/hugetlbfs/inode.c
index 76fb8eb2bea8..d1fb9311d18a 100644
--- a/fs/hugetlbfs/inode.c
+++ b/fs/hugetlbfs/inode.c
@@ -27,7 +27,7 @@
#include <linux/backing-dev.h>
#include <linux/hugetlb.h>
#include <linux/pagevec.h>
-#include <linux/parser.h>
+#include <linux/fs_parser.h>
#include <linux/mman.h>
#include <linux/slab.h>
#include <linux/dnotify.h>
@@ -45,11 +45,17 @@ const struct file_operations hugetlbfs_file_operations;
static const struct inode_operations hugetlbfs_dir_inode_operations;
static const struct inode_operations hugetlbfs_inode_operations;

-struct hugetlbfs_config {
+enum hugetlbfs_size_type { NO_SIZE, SIZE_STD, SIZE_PERCENT };
+
+struct hugetlbfs_fs_context {
struct hstate *hstate;
+ unsigned long long max_size_opt;
+ unsigned long long min_size_opt;
long max_hpages;
long nr_inodes;
long min_hpages;
+ enum hugetlbfs_size_type max_val_type;
+ enum hugetlbfs_size_type min_val_type;
kuid_t uid;
kgid_t gid;
umode_t mode;
@@ -57,22 +63,44 @@ struct hugetlbfs_config {

int sysctl_hugetlb_shm_group;

-enum {
- Opt_size, Opt_nr_inodes,
- Opt_mode, Opt_uid, Opt_gid,
- Opt_pagesize, Opt_min_size,
- Opt_err,
+enum hugetlb_param {
+ Opt_gid,
+ Opt_min_size,
+ Opt_mode,
+ Opt_nr_inodes,
+ Opt_pagesize,
+ Opt_size,
+ Opt_uid,
+ nr__hugetlb_params
+};
+
+static const struct fs_parameter_spec hugetlb_param_specs[nr__hugetlb_params] = {
+ [Opt_gid] = { fs_param_is_u32 },
+ [Opt_min_size] = { fs_param_is_string },
+ [Opt_mode] = { fs_param_is_u32 },
+ [Opt_nr_inodes] = { fs_param_is_string },
+ [Opt_pagesize] = { fs_param_is_string },
+ [Opt_size] = { fs_param_is_string },
+ [Opt_uid] = { fs_param_is_u32 },
+};
+
+static const struct constant_table hugetlb_param_keys[] = {
+ { "gid", Opt_gid },
+ { "min_size", Opt_min_size },
+ { "mode", Opt_mode },
+ { "nr_inodes", Opt_nr_inodes },
+ { "pagesize", Opt_pagesize },
+ { "size", Opt_size },
+ { "uid", Opt_uid },
};

-static const match_table_t tokens = {
- {Opt_size, "size=%s"},
- {Opt_nr_inodes, "nr_inodes=%s"},
- {Opt_mode, "mode=%o"},
- {Opt_uid, "uid=%u"},
- {Opt_gid, "gid=%u"},
- {Opt_pagesize, "pagesize=%s"},
- {Opt_min_size, "min_size=%s"},
- {Opt_err, NULL},
+static const struct fs_parameter_description hugetlb_fs_parameters = {
+ .name = "hugetlbfs",
+ .nr_params = nr__hugetlb_params,
+ .nr_keys = ARRAY_SIZE(hugetlb_param_keys),
+ .keys = hugetlb_param_keys,
+ .specs = hugetlb_param_specs,
+ .no_source = true,
};

#ifdef CONFIG_NUMA
@@ -708,16 +736,16 @@ static int hugetlbfs_setattr(struct dentry *dentry, struct iattr *attr)
}

static struct inode *hugetlbfs_get_root(struct super_block *sb,
- struct hugetlbfs_config *config)
+ struct hugetlbfs_fs_context *ctx)
{
struct inode *inode;

inode = new_inode(sb);
if (inode) {
inode->i_ino = get_next_ino();
- inode->i_mode = S_IFDIR | config->mode;
- inode->i_uid = config->uid;
- inode->i_gid = config->gid;
+ inode->i_mode = S_IFDIR | ctx->mode;
+ inode->i_uid = ctx->uid;
+ inode->i_gid = ctx->gid;
inode->i_atime = inode->i_mtime = inode->i_ctime = current_time(inode);
inode->i_op = &hugetlbfs_dir_inode_operations;
inode->i_fop = &simple_dir_operations;
@@ -1081,8 +1109,6 @@ static const struct super_operations hugetlbfs_ops = {
.show_options = hugetlbfs_show_options,
};

-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
@@ -1105,171 +1131,153 @@ hugetlbfs_size_to_hpages(struct hstate *h, unsigned long long size_opt,
return size_opt;
}

-static int
-hugetlbfs_parse_options(char *options, struct hugetlbfs_config *pconfig)
+/*
+ * Parse one mount parameter.
+ */
+static int hugetlbfs_parse_param(struct fs_context *fc, struct fs_parameter *param)
{
- char *p, *rest;
- substring_t args[MAX_OPT_ARGS];
- int option;
- unsigned long long max_size_opt = 0, min_size_opt = 0;
- enum hugetlbfs_size_type max_val_type = NO_SIZE, min_val_type = NO_SIZE;
+ struct hugetlbfs_fs_context *ctx = fc->fs_private;
+ struct fs_parse_result result;
+ char *rest;
+ unsigned long ps;
+ int ret;
+
+ ret = fs_parse(fc, &hugetlb_fs_parameters, param, &result);
+ if (ret < 0)
+ return ret;

- if (!options)
+ switch (result.key) {
+ case Opt_uid:
+ ctx->uid = make_kuid(current_user_ns(), result.uint_32);
+ if (!uid_valid(ctx->uid))
+ goto bad_val;
return 0;

- while ((p = strsep(&options, ",")) != NULL) {
- int token;
- if (!*p)
- continue;
+ case Opt_gid:
+ ctx->gid = make_kgid(current_user_ns(), result.uint_32);
+ if (!gid_valid(ctx->gid))
+ goto bad_val;
+ return 0;

- token = match_token(p, tokens, args);
- switch (token) {
- case Opt_uid:
- if (match_int(&args[0], &option))
- goto bad_val;
- pconfig->uid = make_kuid(current_user_ns(), option);
- if (!uid_valid(pconfig->uid))
- goto bad_val;
- break;
+ case Opt_mode:
+ ctx->mode = result.uint_32 & 01777U;
+ return 0;

- case Opt_gid:
- if (match_int(&args[0], &option))
- goto bad_val;
- pconfig->gid = make_kgid(current_user_ns(), option);
- if (!gid_valid(pconfig->gid))
- goto bad_val;
- break;
+ case Opt_size:
+ /* memparse() will accept a K/M/G without a digit */
+ if (!isdigit(param->string[0]))
+ goto bad_val;
+ ctx->max_size_opt = memparse(param->string, &rest);
+ ctx->max_val_type = SIZE_STD;
+ if (*rest == '%')
+ ctx->max_val_type = SIZE_PERCENT;
+ return 0;

- case Opt_mode:
- if (match_octal(&args[0], &option))
- goto bad_val;
- pconfig->mode = option & 01777U;
- break;
+ case Opt_nr_inodes:
+ /* memparse() will accept a K/M/G without a digit */
+ if (!isdigit(param->string[0]))
+ goto bad_val;
+ ctx->nr_inodes = memparse(param->string, &rest);
+ return 0;

- case Opt_size: {
- /* memparse() will accept a K/M/G without a digit */
- if (!isdigit(*args[0].from))
- goto bad_val;
- max_size_opt = memparse(args[0].from, &rest);
- max_val_type = SIZE_STD;
- if (*rest == '%')
- max_val_type = SIZE_PERCENT;
- break;
+ case Opt_pagesize:
+ ps = memparse(param->string, &rest);
+ ctx->hstate = size_to_hstate(ps);
+ if (!ctx->hstate) {
+ pr_err("Unsupported page size %lu MB\n", ps >> 20);
+ return -EINVAL;
}
+ return 0;

- case Opt_nr_inodes:
- /* memparse() will accept a K/M/G without a digit */
- if (!isdigit(*args[0].from))
- goto bad_val;
- pconfig->nr_inodes = memparse(args[0].from, &rest);
- break;
+ case Opt_min_size:
+ /* memparse() will accept a K/M/G without a digit */
+ if (!isdigit(param->string[0]))
+ goto bad_val;
+ ctx->min_size_opt = memparse(param->string, &rest);
+ ctx->min_val_type = SIZE_STD;
+ if (*rest == '%')
+ ctx->min_val_type = SIZE_PERCENT;
+ return 0;

- case Opt_pagesize: {
- unsigned long ps;
- ps = memparse(args[0].from, &rest);
- pconfig->hstate = size_to_hstate(ps);
- if (!pconfig->hstate) {
- pr_err("Unsupported page size %lu MB\n",
- ps >> 20);
- return -EINVAL;
- }
- break;
- }
+ default:
+ return -EINVAL;
+ }

- case Opt_min_size: {
- /* memparse() will accept a K/M/G without a digit */
- if (!isdigit(*args[0].from))
- goto bad_val;
- min_size_opt = memparse(args[0].from, &rest);
- min_val_type = SIZE_STD;
- if (*rest == '%')
- min_val_type = SIZE_PERCENT;
- break;
- }
+bad_val:
+ invalf(fc, "hugetlbfs: Bad value '%s' for mount option '%s'\n",
+ param->string, param->key);
+ return -EINVAL;
+}

- default:
- pr_err("Bad mount option: \"%s\"\n", p);
- return -EINVAL;
- break;
- }
- }
+/*
+ * Validate the parsed options.
+ */
+static int hugetlbfs_validate(struct fs_context *fc)
+{
+ struct hugetlbfs_fs_context *ctx = fc->fs_private;

/*
* Use huge page pool size (in hstate) to convert the size
* options to number of huge pages. If NO_SIZE, -1 is returned.
*/
- pconfig->max_hpages = hugetlbfs_size_to_hpages(pconfig->hstate,
- max_size_opt, max_val_type);
- pconfig->min_hpages = hugetlbfs_size_to_hpages(pconfig->hstate,
- min_size_opt, min_val_type);
+ ctx->max_hpages = hugetlbfs_size_to_hpages(ctx->hstate,
+ ctx->max_size_opt,
+ ctx->max_val_type);
+ ctx->min_hpages = hugetlbfs_size_to_hpages(ctx->hstate,
+ ctx->min_size_opt,
+ ctx->min_val_type);

/*
* If max_size was specified, then min_size must be smaller
*/
- if (max_val_type > NO_SIZE &&
- pconfig->min_hpages > pconfig->max_hpages) {
- pr_err("minimum size can not be greater than maximum size\n");
+ if (ctx->max_val_type > NO_SIZE &&
+ ctx->min_hpages > ctx->max_hpages) {
+ pr_err("Minimum size can not be greater than maximum size\n");
return -EINVAL;
}

return 0;
-
-bad_val:
- pr_err("Bad value '%s' for mount option '%s'\n", args[0].from, p);
- return -EINVAL;
}

static int
-hugetlbfs_fill_super(struct super_block *sb, void *data, size_t data_size,
- int silent)
+hugetlbfs_fill_super(struct super_block *sb, struct fs_context *fc)
{
- int ret;
- struct hugetlbfs_config config;
+ struct hugetlbfs_fs_context *ctx =
+ fc->fs_private;
struct hugetlbfs_sb_info *sbinfo;

- 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();
- config.gid = current_fsgid();
- config.mode = 0755;
- config.hstate = &default_hstate;
- config.min_hpages = -1; /* No default minimum size */
- ret = hugetlbfs_parse_options(data, &config);
- if (ret)
- return ret;
-
sbinfo = kmalloc(sizeof(struct hugetlbfs_sb_info), GFP_KERNEL);
if (!sbinfo)
return -ENOMEM;
sb->s_fs_info = sbinfo;
- sbinfo->hstate = config.hstate;
spin_lock_init(&sbinfo->stat_lock);
- 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;
+ sbinfo->hstate = ctx->hstate;
+ sbinfo->max_inodes = ctx->nr_inodes;
+ sbinfo->free_inodes = ctx->nr_inodes;
+ sbinfo->spool = NULL;
+ sbinfo->uid = ctx->uid;
+ sbinfo->gid = ctx->gid;
+ sbinfo->mode = ctx->mode;

/*
* Allocate and initialize subpool if maximum or minimum size is
* specified. Any needed reservations (for minimim size) are taken
* taken when the subpool is created.
*/
- if (config.max_hpages != -1 || config.min_hpages != -1) {
- sbinfo->spool = hugepage_new_subpool(config.hstate,
- config.max_hpages,
- config.min_hpages);
+ if (ctx->max_hpages != -1 || ctx->min_hpages != -1) {
+ sbinfo->spool = hugepage_new_subpool(ctx->hstate,
+ ctx->max_hpages,
+ ctx->min_hpages);
if (!sbinfo->spool)
goto out_free;
}
sb->s_maxbytes = MAX_LFS_FILESIZE;
- sb->s_blocksize = huge_page_size(config.hstate);
- sb->s_blocksize_bits = huge_page_shift(config.hstate);
+ sb->s_blocksize = huge_page_size(ctx->hstate);
+ sb->s_blocksize_bits = huge_page_shift(ctx->hstate);
sb->s_magic = HUGETLBFS_MAGIC;
sb->s_op = &hugetlbfs_ops;
sb->s_time_gran = 1;
- sb->s_root = d_make_root(hugetlbfs_get_root(sb, &config));
+ sb->s_root = d_make_root(hugetlbfs_get_root(sb, ctx));
if (!sb->s_root)
goto out_free;
return 0;
@@ -1279,17 +1287,51 @@ hugetlbfs_fill_super(struct super_block *sb, void *data, size_t data_size,
return -ENOMEM;
}

-static struct dentry *hugetlbfs_mount(struct file_system_type *fs_type,
- int flags, const char *dev_name, void *data, size_t data_size)
+static int hugetlbfs_get_tree(struct fs_context *fc)
+{
+ return vfs_get_super(fc, vfs_get_independent_super, hugetlbfs_fill_super);
+}
+
+static void hugetlbfs_fs_context_free(struct fs_context *fc)
+{
+ kfree(fc->fs_private);
+}
+
+static const struct fs_context_operations hugetlbfs_fs_context_ops = {
+ .free = hugetlbfs_fs_context_free,
+ .parse_param = hugetlbfs_parse_param,
+ .validate = hugetlbfs_validate,
+ .get_tree = hugetlbfs_get_tree,
+};
+
+static int hugetlbfs_init_fs_context(struct fs_context *fc,
+ struct dentry *reference)
{
- return mount_nodev(fs_type, flags, data, data_size,
- hugetlbfs_fill_super);
+ struct hugetlbfs_fs_context *ctx;
+
+ ctx = kzalloc(sizeof(struct hugetlbfs_fs_context), GFP_KERNEL);
+ if (!ctx)
+ return -ENOMEM;
+
+ ctx->max_hpages = -1; /* No limit on size by default */
+ ctx->nr_inodes = -1; /* No limit on number of inodes by default */
+ ctx->uid = current_fsuid();
+ ctx->gid = current_fsgid();
+ ctx->mode = 0755;
+ ctx->hstate = &default_hstate;
+ ctx->min_hpages = -1; /* No default minimum size */
+ ctx->max_val_type = NO_SIZE;
+ ctx->min_val_type = NO_SIZE;
+ fc->fs_private = ctx;
+ fc->ops = &hugetlbfs_fs_context_ops;
+ return 0;
}

static struct file_system_type hugetlbfs_fs_type = {
- .name = "hugetlbfs",
- .mount = hugetlbfs_mount,
- .kill_sb = kill_litter_super,
+ .name = "hugetlbfs",
+ .init_fs_context = hugetlbfs_init_fs_context,
+ .parameters = &hugetlb_fs_parameters,
+ .kill_sb = kill_litter_super,
};

static struct vfsmount *hugetlbfs_vfsmount[HUGE_MAX_HSTATE];
@@ -1396,8 +1438,47 @@ struct file *hugetlb_file_setup(const char *name, size_t size,
return file;
}

+static struct vfsmount *__init mount_one_hugetlbfs(struct hstate *h)
+{
+ struct hugetlbfs_fs_context *ctx;
+ struct fs_context *fc;
+ struct vfsmount *mnt;
+ int ret;
+
+ fc = vfs_new_fs_context(&hugetlbfs_fs_type, NULL, 0,
+ FS_CONTEXT_FOR_KERNEL_MOUNT);
+ if (IS_ERR(fc)) {
+ ret = PTR_ERR(fc);
+ goto err;
+ }
+
+ ctx = fc->fs_private;
+ ctx->hstate = h;
+
+ ret = vfs_get_tree(fc);
+ if (ret < 0)
+ goto err_fc;
+
+ mnt = vfs_create_mount(fc, 0);
+ if (IS_ERR(mnt)) {
+ ret = PTR_ERR(mnt);
+ goto err_fc;
+ }
+
+ put_fs_context(fc);
+ return mnt;
+
+err_fc:
+ put_fs_context(fc);
+err:
+ pr_err("Cannot mount internal hugetlbfs for page size %uK",
+ 1U << (h->order + PAGE_SHIFT - 10));
+ return ERR_PTR(ret);
+}
+
static int __init init_hugetlbfs_fs(void)
{
+ struct vfsmount *mnt;
struct hstate *h;
int error;
int i;
@@ -1420,25 +1501,16 @@ static int __init init_hugetlbfs_fs(void)

i = 0;
for_each_hstate(h) {
- char buf[50];
- unsigned ps_kb = 1U << (h->order + PAGE_SHIFT - 10);
- int n;
-
- n = snprintf(buf, sizeof(buf), "pagesize=%uK", ps_kb);
- hugetlbfs_vfsmount[i] = kern_mount_data(&hugetlbfs_fs_type,
- buf, n + 1);
-
- if (IS_ERR(hugetlbfs_vfsmount[i])) {
- pr_err("Cannot mount internal hugetlbfs for "
- "page size %uK", ps_kb);
- error = PTR_ERR(hugetlbfs_vfsmount[i]);
- hugetlbfs_vfsmount[i] = NULL;
+ mnt = mount_one_hugetlbfs(h);
+ if (IS_ERR(mnt) && i == 0) {
+ error = PTR_ERR(mnt);
+ goto out;
}
+ hugetlbfs_vfsmount[i] = mnt;
i++;
}
- /* Non default hstates are optional */
- if (!IS_ERR_OR_NULL(hugetlbfs_vfsmount[default_hstate_idx]))
- return 0;
+
+ return 0;

out:
kmem_cache_destroy(hugetlbfs_inode_cachep);