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-rw-r--r--mm/shmem.c385
1 files changed, 248 insertions, 137 deletions
diff --git a/mm/shmem.c b/mm/shmem.c
index 2bed4761f279..0f7fd4a85db6 100644
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -37,6 +37,7 @@
#include <linux/khugepaged.h>
#include <linux/hugetlb.h>
#include <linux/frontswap.h>
+#include <linux/fs_parser.h>
#include <asm/tlbflush.h> /* for arch/microblaze update_mmu_cache() */
@@ -107,6 +108,20 @@ struct shmem_falloc {
pgoff_t nr_unswapped; /* how often writepage refused to swap out */
};
+struct shmem_options {
+ unsigned long long blocks;
+ unsigned long long inodes;
+ struct mempolicy *mpol;
+ kuid_t uid;
+ kgid_t gid;
+ umode_t mode;
+ int huge;
+ int seen;
+#define SHMEM_SEEN_BLOCKS 1
+#define SHMEM_SEEN_INODES 2
+#define SHMEM_SEEN_HUGE 4
+};
+
#ifdef CONFIG_TMPFS
static unsigned long shmem_default_max_blocks(void)
{
@@ -3349,16 +3364,126 @@ static const struct export_operations shmem_export_ops = {
.fh_to_dentry = shmem_fh_to_dentry,
};
-static int shmem_parse_options(char *options, struct shmem_sb_info *sbinfo,
- bool remount)
+enum shmem_param {
+ Opt_gid,
+ Opt_huge,
+ Opt_mode,
+ Opt_mpol,
+ Opt_nr_blocks,
+ Opt_nr_inodes,
+ Opt_size,
+ Opt_uid,
+};
+
+static const struct fs_parameter_spec shmem_param_specs[] = {
+ fsparam_u32 ("gid", Opt_gid),
+ fsparam_enum ("huge", Opt_huge),
+ fsparam_u32oct("mode", Opt_mode),
+ fsparam_string("mpol", Opt_mpol),
+ fsparam_string("nr_blocks", Opt_nr_blocks),
+ fsparam_string("nr_inodes", Opt_nr_inodes),
+ fsparam_string("size", Opt_size),
+ fsparam_u32 ("uid", Opt_uid),
+ {}
+};
+
+static const struct fs_parameter_enum shmem_param_enums[] = {
+ { Opt_huge, "never", SHMEM_HUGE_NEVER },
+ { Opt_huge, "always", SHMEM_HUGE_ALWAYS },
+ { Opt_huge, "within_size", SHMEM_HUGE_WITHIN_SIZE },
+ { Opt_huge, "advise", SHMEM_HUGE_ADVISE },
+ {}
+};
+
+const struct fs_parameter_description shmem_fs_parameters = {
+ .name = "tmpfs",
+ .specs = shmem_param_specs,
+ .enums = shmem_param_enums,
+};
+
+static int shmem_parse_one(struct fs_context *fc, struct fs_parameter *param)
{
- char *this_char, *value, *rest;
- struct mempolicy *mpol = NULL;
- uid_t uid;
- gid_t gid;
+ struct shmem_options *ctx = fc->fs_private;
+ struct fs_parse_result result;
+ unsigned long long size;
+ char *rest;
+ int opt;
+
+ opt = fs_parse(fc, &shmem_fs_parameters, param, &result);
+ if (opt < 0)
+ return opt;
+
+ switch (opt) {
+ case Opt_size:
+ size = memparse(param->string, &rest);
+ if (*rest == '%') {
+ size <<= PAGE_SHIFT;
+ size *= totalram_pages();
+ do_div(size, 100);
+ rest++;
+ }
+ if (*rest)
+ goto bad_value;
+ ctx->blocks = DIV_ROUND_UP(size, PAGE_SIZE);
+ ctx->seen |= SHMEM_SEEN_BLOCKS;
+ break;
+ case Opt_nr_blocks:
+ ctx->blocks = memparse(param->string, &rest);
+ if (*rest)
+ goto bad_value;
+ ctx->seen |= SHMEM_SEEN_BLOCKS;
+ break;
+ case Opt_nr_inodes:
+ ctx->inodes = memparse(param->string, &rest);
+ if (*rest)
+ goto bad_value;
+ ctx->seen |= SHMEM_SEEN_INODES;
+ break;
+ case Opt_mode:
+ ctx->mode = result.uint_32 & 07777;
+ break;
+ case Opt_uid:
+ ctx->uid = make_kuid(current_user_ns(), result.uint_32);
+ if (!uid_valid(ctx->uid))
+ goto bad_value;
+ break;
+ case Opt_gid:
+ ctx->gid = make_kgid(current_user_ns(), result.uint_32);
+ if (!gid_valid(ctx->gid))
+ goto bad_value;
+ break;
+ case Opt_huge:
+ ctx->huge = result.uint_32;
+ if (ctx->huge != SHMEM_HUGE_NEVER &&
+ !(IS_ENABLED(CONFIG_TRANSPARENT_HUGE_PAGECACHE) &&
+ has_transparent_hugepage()))
+ goto unsupported_parameter;
+ ctx->seen |= SHMEM_SEEN_HUGE;
+ break;
+ case Opt_mpol:
+ if (IS_ENABLED(CONFIG_NUMA)) {
+ mpol_put(ctx->mpol);
+ ctx->mpol = NULL;
+ if (mpol_parse_str(param->string, &ctx->mpol))
+ goto bad_value;
+ break;
+ }
+ goto unsupported_parameter;
+ }
+ return 0;
+
+unsupported_parameter:
+ return invalf(fc, "tmpfs: Unsupported parameter '%s'", param->key);
+bad_value:
+ return invalf(fc, "tmpfs: Bad value for '%s'", param->key);
+}
+
+static int shmem_parse_options(struct fs_context *fc, void *data)
+{
+ char *options = data;
while (options != NULL) {
- this_char = options;
+ char *this_char = options;
for (;;) {
/*
* NUL-terminate this option: unfortunately,
@@ -3374,139 +3499,83 @@ static int shmem_parse_options(char *options, struct shmem_sb_info *sbinfo,
break;
}
}
- if (!*this_char)
- continue;
- if ((value = strchr(this_char,'=')) != NULL) {
- *value++ = 0;
- } else {
- pr_err("tmpfs: No value for mount option '%s'\n",
- this_char);
- goto error;
- }
-
- if (!strcmp(this_char,"size")) {
- unsigned long long size;
- size = memparse(value,&rest);
- if (*rest == '%') {
- size <<= PAGE_SHIFT;
- size *= totalram_pages();
- do_div(size, 100);
- rest++;
+ if (*this_char) {
+ char *value = strchr(this_char,'=');
+ size_t len = 0;
+ int err;
+
+ if (value) {
+ *value++ = '\0';
+ len = strlen(value);
}
- if (*rest)
- goto bad_val;
- sbinfo->max_blocks =
- DIV_ROUND_UP(size, PAGE_SIZE);
- } else if (!strcmp(this_char,"nr_blocks")) {
- sbinfo->max_blocks = memparse(value, &rest);
- if (*rest)
- goto bad_val;
- } else if (!strcmp(this_char,"nr_inodes")) {
- sbinfo->max_inodes = memparse(value, &rest);
- if (*rest)
- goto bad_val;
- } else if (!strcmp(this_char,"mode")) {
- if (remount)
- continue;
- sbinfo->mode = simple_strtoul(value, &rest, 8) & 07777;
- if (*rest)
- goto bad_val;
- } else if (!strcmp(this_char,"uid")) {
- if (remount)
- continue;
- uid = simple_strtoul(value, &rest, 0);
- if (*rest)
- goto bad_val;
- sbinfo->uid = make_kuid(current_user_ns(), uid);
- if (!uid_valid(sbinfo->uid))
- goto bad_val;
- } else if (!strcmp(this_char,"gid")) {
- if (remount)
- continue;
- gid = simple_strtoul(value, &rest, 0);
- if (*rest)
- goto bad_val;
- sbinfo->gid = make_kgid(current_user_ns(), gid);
- if (!gid_valid(sbinfo->gid))
- goto bad_val;
-#ifdef CONFIG_TRANSPARENT_HUGE_PAGECACHE
- } else if (!strcmp(this_char, "huge")) {
- int huge;
- huge = shmem_parse_huge(value);
- if (huge < 0)
- goto bad_val;
- if (!has_transparent_hugepage() &&
- huge != SHMEM_HUGE_NEVER)
- goto bad_val;
- sbinfo->huge = huge;
-#endif
-#ifdef CONFIG_NUMA
- } else if (!strcmp(this_char,"mpol")) {
- mpol_put(mpol);
- mpol = NULL;
- if (mpol_parse_str(value, &mpol))
- goto bad_val;
-#endif
- } else {
- pr_err("tmpfs: Bad mount option %s\n", this_char);
- goto error;
+ err = vfs_parse_fs_string(fc, this_char, value, len);
+ if (err < 0)
+ return err;
}
}
- sbinfo->mpol = mpol;
return 0;
-
-bad_val:
- pr_err("tmpfs: Bad value '%s' for mount option '%s'\n",
- value, this_char);
-error:
- mpol_put(mpol);
- return 1;
-
}
-static int shmem_remount_fs(struct super_block *sb, int *flags, char *data)
+/*
+ * Reconfigure a shmem filesystem.
+ *
+ * Note that we disallow change from limited->unlimited blocks/inodes while any
+ * are in use; but we must separately disallow unlimited->limited, because in
+ * that case we have no record of how much is already in use.
+ */
+static int shmem_reconfigure(struct fs_context *fc)
{
- struct shmem_sb_info *sbinfo = SHMEM_SB(sb);
- struct shmem_sb_info config = *sbinfo;
+ struct shmem_options *ctx = fc->fs_private;
+ struct shmem_sb_info *sbinfo = SHMEM_SB(fc->root->d_sb);
unsigned long inodes;
- int error = -EINVAL;
-
- config.mpol = NULL;
- if (shmem_parse_options(data, &config, true))
- return error;
+ const char *err;
spin_lock(&sbinfo->stat_lock);
inodes = sbinfo->max_inodes - sbinfo->free_inodes;
- if (percpu_counter_compare(&sbinfo->used_blocks, config.max_blocks) > 0)
- goto out;
- if (config.max_inodes < inodes)
- goto out;
- /*
- * Those tests disallow limited->unlimited while any are in use;
- * but we must separately disallow unlimited->limited, because
- * in that case we have no record of how much is already in use.
- */
- if (config.max_blocks && !sbinfo->max_blocks)
- goto out;
- if (config.max_inodes && !sbinfo->max_inodes)
- goto out;
+ if ((ctx->seen & SHMEM_SEEN_BLOCKS) && ctx->blocks) {
+ if (!sbinfo->max_blocks) {
+ err = "Cannot retroactively limit size";
+ goto out;
+ }
+ if (percpu_counter_compare(&sbinfo->used_blocks,
+ ctx->blocks) > 0) {
+ err = "Too small a size for current use";
+ goto out;
+ }
+ }
+ if ((ctx->seen & SHMEM_SEEN_INODES) && ctx->inodes) {
+ if (!sbinfo->max_inodes) {
+ err = "Cannot retroactively limit inodes";
+ goto out;
+ }
+ if (ctx->inodes < inodes) {
+ err = "Too few inodes for current use";
+ goto out;
+ }
+ }
- error = 0;
- sbinfo->huge = config.huge;
- sbinfo->max_blocks = config.max_blocks;
- sbinfo->max_inodes = config.max_inodes;
- sbinfo->free_inodes = config.max_inodes - inodes;
+ if (ctx->seen & SHMEM_SEEN_HUGE)
+ sbinfo->huge = ctx->huge;
+ if (ctx->seen & SHMEM_SEEN_BLOCKS)
+ sbinfo->max_blocks = ctx->blocks;
+ if (ctx->seen & SHMEM_SEEN_INODES) {
+ sbinfo->max_inodes = ctx->inodes;
+ sbinfo->free_inodes = ctx->inodes - inodes;
+ }
/*
* Preserve previous mempolicy unless mpol remount option was specified.
*/
- if (config.mpol) {
+ if (ctx->mpol) {
mpol_put(sbinfo->mpol);
- sbinfo->mpol = config.mpol; /* transfers initial ref */
+ sbinfo->mpol = ctx->mpol; /* transfers initial ref */
+ ctx->mpol = NULL;
}
+ spin_unlock(&sbinfo->stat_lock);
+ return 0;
out:
spin_unlock(&sbinfo->stat_lock);
- return error;
+ return invalf(fc, "tmpfs: %s", err);
}
static int shmem_show_options(struct seq_file *seq, struct dentry *root)
@@ -3547,8 +3616,9 @@ static void shmem_put_super(struct super_block *sb)
sb->s_fs_info = NULL;
}
-int shmem_fill_super(struct super_block *sb, void *data, int silent)
+static int shmem_fill_super(struct super_block *sb, struct fs_context *fc)
{
+ struct shmem_options *ctx = fc->fs_private;
struct inode *inode;
struct shmem_sb_info *sbinfo;
int err = -ENOMEM;
@@ -3559,9 +3629,6 @@ int shmem_fill_super(struct super_block *sb, void *data, int silent)
if (!sbinfo)
return -ENOMEM;
- sbinfo->mode = 0777 | S_ISVTX;
- sbinfo->uid = current_fsuid();
- sbinfo->gid = current_fsgid();
sb->s_fs_info = sbinfo;
#ifdef CONFIG_TMPFS
@@ -3571,12 +3638,10 @@ int shmem_fill_super(struct super_block *sb, void *data, int silent)
* but the internal instance is left unlimited.
*/
if (!(sb->s_flags & SB_KERNMOUNT)) {
- sbinfo->max_blocks = shmem_default_max_blocks();
- sbinfo->max_inodes = shmem_default_max_inodes();
- if (shmem_parse_options(data, sbinfo, false)) {
- err = -EINVAL;
- goto failed;
- }
+ if (!(ctx->seen & SHMEM_SEEN_BLOCKS))
+ ctx->blocks = shmem_default_max_blocks();
+ if (!(ctx->seen & SHMEM_SEEN_INODES))
+ ctx->inodes = shmem_default_max_inodes();
} else {
sb->s_flags |= SB_NOUSER;
}
@@ -3585,11 +3650,18 @@ int shmem_fill_super(struct super_block *sb, void *data, int silent)
#else
sb->s_flags |= SB_NOUSER;
#endif
+ sbinfo->max_blocks = ctx->blocks;
+ sbinfo->free_inodes = sbinfo->max_inodes = ctx->inodes;
+ sbinfo->uid = ctx->uid;
+ sbinfo->gid = ctx->gid;
+ sbinfo->mode = ctx->mode;
+ sbinfo->huge = ctx->huge;
+ sbinfo->mpol = ctx->mpol;
+ ctx->mpol = NULL;
spin_lock_init(&sbinfo->stat_lock);
if (percpu_counter_init(&sbinfo->used_blocks, 0, GFP_KERNEL))
goto failed;
- sbinfo->free_inodes = sbinfo->max_inodes;
spin_lock_init(&sbinfo->shrinklist_lock);
INIT_LIST_HEAD(&sbinfo->shrinklist);
@@ -3622,6 +3694,31 @@ failed:
return err;
}
+static int shmem_get_tree(struct fs_context *fc)
+{
+ return get_tree_nodev(fc, shmem_fill_super);
+}
+
+static void shmem_free_fc(struct fs_context *fc)
+{
+ struct shmem_options *ctx = fc->fs_private;
+
+ if (ctx) {
+ mpol_put(ctx->mpol);
+ kfree(ctx);
+ }
+}
+
+static const struct fs_context_operations shmem_fs_context_ops = {
+ .free = shmem_free_fc,
+ .get_tree = shmem_get_tree,
+#ifdef CONFIG_TMPFS
+ .parse_monolithic = shmem_parse_options,
+ .parse_param = shmem_parse_one,
+ .reconfigure = shmem_reconfigure,
+#endif
+};
+
static struct kmem_cache *shmem_inode_cachep;
static struct inode *shmem_alloc_inode(struct super_block *sb)
@@ -3738,7 +3835,6 @@ static const struct super_operations shmem_ops = {
.destroy_inode = shmem_destroy_inode,
#ifdef CONFIG_TMPFS
.statfs = shmem_statfs,
- .remount_fs = shmem_remount_fs,
.show_options = shmem_show_options,
#endif
.evict_inode = shmem_evict_inode,
@@ -3759,16 +3855,30 @@ static const struct vm_operations_struct shmem_vm_ops = {
#endif
};
-static struct dentry *shmem_mount(struct file_system_type *fs_type,
- int flags, const char *dev_name, void *data)
+int shmem_init_fs_context(struct fs_context *fc)
{
- return mount_nodev(fs_type, flags, data, shmem_fill_super);
+ struct shmem_options *ctx;
+
+ ctx = kzalloc(sizeof(struct shmem_options), GFP_KERNEL);
+ if (!ctx)
+ return -ENOMEM;
+
+ ctx->mode = 0777 | S_ISVTX;
+ ctx->uid = current_fsuid();
+ ctx->gid = current_fsgid();
+
+ fc->fs_private = ctx;
+ fc->ops = &shmem_fs_context_ops;
+ return 0;
}
static struct file_system_type shmem_fs_type = {
.owner = THIS_MODULE,
.name = "tmpfs",
- .mount = shmem_mount,
+ .init_fs_context = shmem_init_fs_context,
+#ifdef CONFIG_TMPFS
+ .parameters = &shmem_fs_parameters,
+#endif
.kill_sb = kill_litter_super,
.fs_flags = FS_USERNS_MOUNT,
};
@@ -3912,7 +4022,8 @@ bool shmem_huge_enabled(struct vm_area_struct *vma)
static struct file_system_type shmem_fs_type = {
.name = "tmpfs",
- .mount = ramfs_mount,
+ .init_fs_context = ramfs_init_fs_context,
+ .parameters = &ramfs_fs_parameters,
.kill_sb = kill_litter_super,
.fs_flags = FS_USERNS_MOUNT,
};