--- /dev/null
+/*
+ * hugetlbpage-backed filesystem. Based on ramfs.
+ *
+ * Nadia Yvette Chambers, 2002
+ *
+ * Copyright (C) 2002 Linus Torvalds.
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/module.h>
+#include <linux/thread_info.h>
+#include <asm/current.h>
+#include <linux/sched.h> /* remove ASAP */
+#include <linux/fs.h>
+#include <linux/mount.h>
+#include <linux/file.h>
+#include <linux/kernel.h>
+#include <linux/writeback.h>
+#include <linux/pagemap.h>
+#include <linux/highmem.h>
+#include <linux/init.h>
+#include <linux/string.h>
+#include <linux/capability.h>
+#include <linux/ctype.h>
+#include <linux/backing-dev.h>
+#include <linux/hugetlb.h>
+#include <linux/pagevec.h>
+#include <linux/parser.h>
+#include <linux/mman.h>
+#include <linux/slab.h>
+#include <linux/dnotify.h>
+#include <linux/statfs.h>
+#include <linux/security.h>
+#include <linux/magic.h>
+#include <linux/migrate.h>
+#include <linux/uio.h>
+
+#include <asm/uaccess.h>
+
+static const struct super_operations hugetlbfs_ops;
+static const struct address_space_operations hugetlbfs_aops;
+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 {
+ kuid_t uid;
+ kgid_t gid;
+ umode_t mode;
+ long max_hpages;
+ long nr_inodes;
+ struct hstate *hstate;
+ long min_hpages;
+};
+
+struct hugetlbfs_inode_info {
+ struct shared_policy policy;
+ struct inode vfs_inode;
+};
+
+static inline struct hugetlbfs_inode_info *HUGETLBFS_I(struct inode *inode)
+{
+ return container_of(inode, struct hugetlbfs_inode_info, vfs_inode);
+}
+
+int sysctl_hugetlb_shm_group;
+
+enum {
+ Opt_size, Opt_nr_inodes,
+ Opt_mode, Opt_uid, Opt_gid,
+ Opt_pagesize, Opt_min_size,
+ Opt_err,
+};
+
+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 void huge_pagevec_release(struct pagevec *pvec)
+{
+ int i;
+
+ for (i = 0; i < pagevec_count(pvec); ++i)
+ put_page(pvec->pages[i]);
+
+ pagevec_reinit(pvec);
+}
+
+static int hugetlbfs_file_mmap(struct file *file, struct vm_area_struct *vma)
+{
+ struct inode *inode = file_inode(file);
+ loff_t len, vma_len;
+ int ret;
+ struct hstate *h = hstate_file(file);
+
+ /*
+ * vma address alignment (but not the pgoff alignment) has
+ * already been checked by prepare_hugepage_range. If you add
+ * any error returns here, do so after setting VM_HUGETLB, so
+ * is_vm_hugetlb_page tests below unmap_region go the right
+ * way when do_mmap_pgoff unwinds (may be important on powerpc
+ * and ia64).
+ */
+ vma->vm_flags |= VM_HUGETLB | VM_DONTEXPAND;
+ vma->vm_ops = &hugetlb_vm_ops;
+
+ if (vma->vm_pgoff & (~huge_page_mask(h) >> PAGE_SHIFT))
+ return -EINVAL;
+
+ vma_len = (loff_t)(vma->vm_end - vma->vm_start);
+
+ mutex_lock(&inode->i_mutex);
+ file_accessed(file);
+
+ ret = -ENOMEM;
+ len = vma_len + ((loff_t)vma->vm_pgoff << PAGE_SHIFT);
+
+ if (hugetlb_reserve_pages(inode,
+ vma->vm_pgoff >> huge_page_order(h),
+ len >> huge_page_shift(h), vma,
+ vma->vm_flags))
+ goto out;
+
+ ret = 0;
+ hugetlb_prefault_arch_hook(vma->vm_mm);
+ if (vma->vm_flags & VM_WRITE && inode->i_size < len)
+ inode->i_size = len;
+out:
+ mutex_unlock(&inode->i_mutex);
+
+ return ret;
+}
+
+/*
+ * Called under down_write(mmap_sem).
+ */
+
+#ifndef HAVE_ARCH_HUGETLB_UNMAPPED_AREA
+static unsigned long
+hugetlb_get_unmapped_area(struct file *file, unsigned long addr,
+ unsigned long len, unsigned long pgoff, unsigned long flags)
+{
+ struct mm_struct *mm = current->mm;
+ struct vm_area_struct *vma;
+ struct hstate *h = hstate_file(file);
+ struct vm_unmapped_area_info info;
+
+ if (len & ~huge_page_mask(h))
+ return -EINVAL;
+ if (len > TASK_SIZE)
+ return -ENOMEM;
+
+ if (flags & MAP_FIXED) {
+ if (prepare_hugepage_range(file, addr, len))
+ return -EINVAL;
+ return addr;
+ }
+
+ if (addr) {
+ addr = ALIGN(addr, huge_page_size(h));
+ vma = find_vma(mm, addr);
+ if (TASK_SIZE - len >= addr &&
+ (!vma || addr + len <= vma->vm_start))
+ return addr;
+ }
+
+ info.flags = 0;
+ info.length = len;
+ info.low_limit = TASK_UNMAPPED_BASE;
+ info.high_limit = TASK_SIZE;
+ info.align_mask = PAGE_MASK & ~huge_page_mask(h);
+ info.align_offset = 0;
+ return vm_unmapped_area(&info);
+}
+#endif
+
+static size_t
+hugetlbfs_read_actor(struct page *page, unsigned long offset,
+ struct iov_iter *to, unsigned long size)
+{
+ size_t copied = 0;
+ int i, chunksize;
+
+ /* Find which 4k chunk and offset with in that chunk */
+ i = offset >> PAGE_CACHE_SHIFT;
+ offset = offset & ~PAGE_CACHE_MASK;
+
+ while (size) {
+ size_t n;
+ chunksize = PAGE_CACHE_SIZE;
+ if (offset)
+ chunksize -= offset;
+ if (chunksize > size)
+ chunksize = size;
+ n = copy_page_to_iter(&page[i], offset, chunksize, to);
+ copied += n;
+ if (n != chunksize)
+ return copied;
+ offset = 0;
+ size -= chunksize;
+ i++;
+ }
+ return copied;
+}
+
+/*
+ * Support for read() - Find the page attached to f_mapping and copy out the
+ * data. Its *very* similar to do_generic_mapping_read(), we can't use that
+ * since it has PAGE_CACHE_SIZE assumptions.
+ */
+static ssize_t hugetlbfs_read_iter(struct kiocb *iocb, struct iov_iter *to)
+{
+ struct file *file = iocb->ki_filp;
+ struct hstate *h = hstate_file(file);
+ struct address_space *mapping = file->f_mapping;
+ struct inode *inode = mapping->host;
+ unsigned long index = iocb->ki_pos >> huge_page_shift(h);
+ unsigned long offset = iocb->ki_pos & ~huge_page_mask(h);
+ unsigned long end_index;
+ loff_t isize;
+ ssize_t retval = 0;
+
+ while (iov_iter_count(to)) {
+ struct page *page;
+ size_t nr, copied;
+
+ /* nr is the maximum number of bytes to copy from this page */
+ nr = huge_page_size(h);
+ isize = i_size_read(inode);
+ if (!isize)
+ break;
+ end_index = (isize - 1) >> huge_page_shift(h);
+ if (index > end_index)
+ break;
+ if (index == end_index) {
+ nr = ((isize - 1) & ~huge_page_mask(h)) + 1;
+ if (nr <= offset)
+ break;
+ }
+ nr = nr - offset;
+
+ /* Find the page */
+ page = find_lock_page(mapping, index);
+ if (unlikely(page == NULL)) {
+ /*
+ * We have a HOLE, zero out the user-buffer for the
+ * length of the hole or request.
+ */
+ copied = iov_iter_zero(nr, to);
+ } else {
+ unlock_page(page);
+
+ /*
+ * We have the page, copy it to user space buffer.
+ */
+ copied = hugetlbfs_read_actor(page, offset, to, nr);
+ page_cache_release(page);
+ }
+ offset += copied;
+ retval += copied;
+ if (copied != nr && iov_iter_count(to)) {
+ if (!retval)
+ retval = -EFAULT;
+ break;
+ }
+ index += offset >> huge_page_shift(h);
+ offset &= ~huge_page_mask(h);
+ }
+ iocb->ki_pos = ((loff_t)index << huge_page_shift(h)) + offset;
+ return retval;
+}
+
+static int hugetlbfs_write_begin(struct file *file,
+ struct address_space *mapping,
+ loff_t pos, unsigned len, unsigned flags,
+ struct page **pagep, void **fsdata)
+{
+ return -EINVAL;
+}
+
+static int hugetlbfs_write_end(struct file *file, struct address_space *mapping,
+ loff_t pos, unsigned len, unsigned copied,
+ struct page *page, void *fsdata)
+{
+ BUG();
+ return -EINVAL;
+}
+
+static void truncate_huge_page(struct page *page)
+{
+ ClearPageDirty(page);
+ ClearPageUptodate(page);
+ delete_from_page_cache(page);
+}
+
+static void truncate_hugepages(struct inode *inode, loff_t lstart)
+{
+ struct hstate *h = hstate_inode(inode);
+ struct address_space *mapping = &inode->i_data;
+ const pgoff_t start = lstart >> huge_page_shift(h);
+ struct pagevec pvec;
+ pgoff_t next;
+ int i, freed = 0;
+
+ pagevec_init(&pvec, 0);
+ next = start;
+ while (1) {
+ if (!pagevec_lookup(&pvec, mapping, next, PAGEVEC_SIZE)) {
+ if (next == start)
+ break;
+ next = start;
+ continue;
+ }
+
+ for (i = 0; i < pagevec_count(&pvec); ++i) {
+ struct page *page = pvec.pages[i];
+
+ lock_page(page);
+ if (page->index > next)
+ next = page->index;
+ ++next;
+ truncate_huge_page(page);
+ unlock_page(page);
+ freed++;
+ }
+ huge_pagevec_release(&pvec);
+ }
+ BUG_ON(!lstart && mapping->nrpages);
+ hugetlb_unreserve_pages(inode, start, freed);
+}
+
+static void hugetlbfs_evict_inode(struct inode *inode)
+{
+ struct resv_map *resv_map;
+
+ truncate_hugepages(inode, 0);
+ resv_map = (struct resv_map *)inode->i_mapping->private_data;
+ /* root inode doesn't have the resv_map, so we should check it */
+ if (resv_map)
+ resv_map_release(&resv_map->refs);
+ clear_inode(inode);
+}
+
+static inline void
+hugetlb_vmtruncate_list(struct rb_root *root, pgoff_t pgoff)
+{
+ struct vm_area_struct *vma;
+
+ vma_interval_tree_foreach(vma, root, pgoff, ULONG_MAX) {
+ unsigned long v_offset;
+
+ /*
+ * Can the expression below overflow on 32-bit arches?
+ * No, because the interval tree returns us only those vmas
+ * which overlap the truncated area starting at pgoff,
+ * and no vma on a 32-bit arch can span beyond the 4GB.
+ */
+ if (vma->vm_pgoff < pgoff)
+ v_offset = (pgoff - vma->vm_pgoff) << PAGE_SHIFT;
+ else
+ v_offset = 0;
+
+ unmap_hugepage_range(vma, vma->vm_start + v_offset,
+ vma->vm_end, NULL);
+ }
+}
+
+static int hugetlb_vmtruncate(struct inode *inode, loff_t offset)
+{
+ pgoff_t pgoff;
+ struct address_space *mapping = inode->i_mapping;
+ struct hstate *h = hstate_inode(inode);
+
+ BUG_ON(offset & ~huge_page_mask(h));
+ pgoff = offset >> PAGE_SHIFT;
+
+ i_size_write(inode, offset);
+ i_mmap_lock_write(mapping);
+ if (!RB_EMPTY_ROOT(&mapping->i_mmap))
+ hugetlb_vmtruncate_list(&mapping->i_mmap, pgoff);
+ i_mmap_unlock_write(mapping);
+ truncate_hugepages(inode, offset);
+ return 0;
+}
+
+static int hugetlbfs_setattr(struct dentry *dentry, struct iattr *attr)
+{
+ struct inode *inode = d_inode(dentry);
+ struct hstate *h = hstate_inode(inode);
+ int error;
+ unsigned int ia_valid = attr->ia_valid;
+
+ BUG_ON(!inode);
+
+ error = inode_change_ok(inode, attr);
+ if (error)
+ return error;
+
+ if (ia_valid & ATTR_SIZE) {
+ error = -EINVAL;
+ if (attr->ia_size & ~huge_page_mask(h))
+ return -EINVAL;
+ error = hugetlb_vmtruncate(inode, attr->ia_size);
+ if (error)
+ return error;
+ }
+
+ setattr_copy(inode, attr);
+ mark_inode_dirty(inode);
+ return 0;
+}
+
+static struct inode *hugetlbfs_get_root(struct super_block *sb,
+ struct hugetlbfs_config *config)
+{
+ struct inode *inode;
+
+ inode = new_inode(sb);
+ if (inode) {
+ struct hugetlbfs_inode_info *info;
+ 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_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
+ info = HUGETLBFS_I(inode);
+ mpol_shared_policy_init(&info->policy, NULL);
+ inode->i_op = &hugetlbfs_dir_inode_operations;
+ inode->i_fop = &simple_dir_operations;
+ /* directory inodes start off with i_nlink == 2 (for "." entry) */
+ inc_nlink(inode);
+ lockdep_annotate_inode_mutex_key(inode);
+ }
+ return inode;
+}
+
+/*
+ * Hugetlbfs is not reclaimable; therefore its i_mmap_rwsem will never
+ * be taken from reclaim -- unlike regular filesystems. This needs an
+ * annotation because huge_pmd_share() does an allocation under
+ * i_mmap_rwsem.
+ */
+static struct lock_class_key hugetlbfs_i_mmap_rwsem_key;
+
+static struct inode *hugetlbfs_get_inode(struct super_block *sb,
+ struct inode *dir,
+ umode_t mode, dev_t dev)
+{
+ struct inode *inode;
+ struct resv_map *resv_map;
+
+ resv_map = resv_map_alloc();
+ if (!resv_map)
+ return NULL;
+
+ inode = new_inode(sb);
+ if (inode) {
+ struct hugetlbfs_inode_info *info;
+ inode->i_ino = get_next_ino();
+ inode_init_owner(inode, dir, mode);
+ lockdep_set_class(&inode->i_mapping->i_mmap_rwsem,
+ &hugetlbfs_i_mmap_rwsem_key);
+ inode->i_mapping->a_ops = &hugetlbfs_aops;
+ inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
+ inode->i_mapping->private_data = resv_map;
+ info = HUGETLBFS_I(inode);
+ /*
+ * The policy is initialized here even if we are creating a
+ * private inode because initialization simply creates an
+ * an empty rb tree and calls spin_lock_init(), later when we
+ * call mpol_free_shared_policy() it will just return because
+ * the rb tree will still be empty.
+ */
+ mpol_shared_policy_init(&info->policy, NULL);
+ switch (mode & S_IFMT) {
+ default:
+ init_special_inode(inode, mode, dev);
+ break;
+ case S_IFREG:
+ inode->i_op = &hugetlbfs_inode_operations;
+ inode->i_fop = &hugetlbfs_file_operations;
+ break;
+ case S_IFDIR:
+ inode->i_op = &hugetlbfs_dir_inode_operations;
+ inode->i_fop = &simple_dir_operations;
+
+ /* directory inodes start off with i_nlink == 2 (for "." entry) */
+ inc_nlink(inode);
+ break;
+ case S_IFLNK:
+ inode->i_op = &page_symlink_inode_operations;
+ break;
+ }
+ lockdep_annotate_inode_mutex_key(inode);
+ } else
+ kref_put(&resv_map->refs, resv_map_release);
+
+ return inode;
+}
+
+/*
+ * File creation. Allocate an inode, and we're done..
+ */
+static int hugetlbfs_mknod(struct inode *dir,
+ struct dentry *dentry, umode_t mode, dev_t dev)
+{
+ struct inode *inode;
+ int error = -ENOSPC;
+
+ inode = hugetlbfs_get_inode(dir->i_sb, dir, mode, dev);
+ if (inode) {
+ dir->i_ctime = dir->i_mtime = CURRENT_TIME;
+ d_instantiate(dentry, inode);
+ dget(dentry); /* Extra count - pin the dentry in core */
+ error = 0;
+ }
+ return error;
+}
+
+static int hugetlbfs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
+{
+ int retval = hugetlbfs_mknod(dir, dentry, mode | S_IFDIR, 0);
+ if (!retval)
+ inc_nlink(dir);
+ return retval;
+}
+
+static int hugetlbfs_create(struct inode *dir, struct dentry *dentry, umode_t mode, bool excl)
+{
+ return hugetlbfs_mknod(dir, dentry, mode | S_IFREG, 0);
+}
+
+static int hugetlbfs_symlink(struct inode *dir,
+ struct dentry *dentry, const char *symname)
+{
+ struct inode *inode;
+ int error = -ENOSPC;
+
+ inode = hugetlbfs_get_inode(dir->i_sb, dir, S_IFLNK|S_IRWXUGO, 0);
+ if (inode) {
+ int l = strlen(symname)+1;
+ error = page_symlink(inode, symname, l);
+ if (!error) {
+ d_instantiate(dentry, inode);
+ dget(dentry);
+ } else
+ iput(inode);
+ }
+ dir->i_ctime = dir->i_mtime = CURRENT_TIME;
+
+ return error;
+}
+
+/*
+ * mark the head page dirty
+ */
+static int hugetlbfs_set_page_dirty(struct page *page)
+{
+ struct page *head = compound_head(page);
+
+ SetPageDirty(head);
+ return 0;
+}
+
+static int hugetlbfs_migrate_page(struct address_space *mapping,
+ struct page *newpage, struct page *page,
+ enum migrate_mode mode)
+{
+ int rc;
+
+ rc = migrate_huge_page_move_mapping(mapping, newpage, page);
+ if (rc != MIGRATEPAGE_SUCCESS)
+ return rc;
+ migrate_page_copy(newpage, page);
+
+ return MIGRATEPAGE_SUCCESS;
+}
+
+static int hugetlbfs_statfs(struct dentry *dentry, struct kstatfs *buf)
+{
+ struct hugetlbfs_sb_info *sbinfo = HUGETLBFS_SB(dentry->d_sb);
+ struct hstate *h = hstate_inode(d_inode(dentry));
+
+ buf->f_type = HUGETLBFS_MAGIC;
+ buf->f_bsize = huge_page_size(h);
+ if (sbinfo) {
+ spin_lock(&sbinfo->stat_lock);
+ /* If no limits set, just report 0 for max/free/used
+ * blocks, like simple_statfs() */
+ if (sbinfo->spool) {
+ long free_pages;
+
+ spin_lock(&sbinfo->spool->lock);
+ buf->f_blocks = sbinfo->spool->max_hpages;
+ free_pages = sbinfo->spool->max_hpages
+ - sbinfo->spool->used_hpages;
+ buf->f_bavail = buf->f_bfree = free_pages;
+ spin_unlock(&sbinfo->spool->lock);
+ buf->f_files = sbinfo->max_inodes;
+ buf->f_ffree = sbinfo->free_inodes;
+ }
+ spin_unlock(&sbinfo->stat_lock);
+ }
+ buf->f_namelen = NAME_MAX;
+ return 0;
+}
+
+static void hugetlbfs_put_super(struct super_block *sb)
+{
+ struct hugetlbfs_sb_info *sbi = HUGETLBFS_SB(sb);
+
+ if (sbi) {
+ sb->s_fs_info = NULL;
+
+ if (sbi->spool)
+ hugepage_put_subpool(sbi->spool);
+
+ kfree(sbi);
+ }
+}
+
+static inline int hugetlbfs_dec_free_inodes(struct hugetlbfs_sb_info *sbinfo)
+{
+ if (sbinfo->free_inodes >= 0) {
+ spin_lock(&sbinfo->stat_lock);
+ if (unlikely(!sbinfo->free_inodes)) {
+ spin_unlock(&sbinfo->stat_lock);
+ return 0;
+ }
+ sbinfo->free_inodes--;
+ spin_unlock(&sbinfo->stat_lock);
+ }
+
+ return 1;
+}
+
+static void hugetlbfs_inc_free_inodes(struct hugetlbfs_sb_info *sbinfo)
+{
+ if (sbinfo->free_inodes >= 0) {
+ spin_lock(&sbinfo->stat_lock);
+ sbinfo->free_inodes++;
+ spin_unlock(&sbinfo->stat_lock);
+ }
+}
+
+
+static struct kmem_cache *hugetlbfs_inode_cachep;
+
+static struct inode *hugetlbfs_alloc_inode(struct super_block *sb)
+{
+ struct hugetlbfs_sb_info *sbinfo = HUGETLBFS_SB(sb);
+ struct hugetlbfs_inode_info *p;
+
+ if (unlikely(!hugetlbfs_dec_free_inodes(sbinfo)))
+ return NULL;
+ p = kmem_cache_alloc(hugetlbfs_inode_cachep, GFP_KERNEL);
+ if (unlikely(!p)) {
+ hugetlbfs_inc_free_inodes(sbinfo);
+ return NULL;
+ }
+ return &p->vfs_inode;
+}
+
+static void hugetlbfs_i_callback(struct rcu_head *head)
+{
+ struct inode *inode = container_of(head, struct inode, i_rcu);
+ kmem_cache_free(hugetlbfs_inode_cachep, HUGETLBFS_I(inode));
+}
+
+static void hugetlbfs_destroy_inode(struct inode *inode)
+{
+ hugetlbfs_inc_free_inodes(HUGETLBFS_SB(inode->i_sb));
+ mpol_free_shared_policy(&HUGETLBFS_I(inode)->policy);
+ call_rcu(&inode->i_rcu, hugetlbfs_i_callback);
+}
+
+static const struct address_space_operations hugetlbfs_aops = {
+ .write_begin = hugetlbfs_write_begin,
+ .write_end = hugetlbfs_write_end,
+ .set_page_dirty = hugetlbfs_set_page_dirty,
+ .migratepage = hugetlbfs_migrate_page,
+};
+
+
+static void init_once(void *foo)
+{
+ struct hugetlbfs_inode_info *ei = (struct hugetlbfs_inode_info *)foo;
+
+ inode_init_once(&ei->vfs_inode);
+}
+
+const struct file_operations hugetlbfs_file_operations = {
+ .read_iter = hugetlbfs_read_iter,
+ .mmap = hugetlbfs_file_mmap,
+ .fsync = noop_fsync,
+ .get_unmapped_area = hugetlb_get_unmapped_area,
+ .llseek = default_llseek,
+};
+
+static const struct inode_operations hugetlbfs_dir_inode_operations = {
+ .create = hugetlbfs_create,
+ .lookup = simple_lookup,
+ .link = simple_link,
+ .unlink = simple_unlink,
+ .symlink = hugetlbfs_symlink,
+ .mkdir = hugetlbfs_mkdir,
+ .rmdir = simple_rmdir,
+ .mknod = hugetlbfs_mknod,
+ .rename = simple_rename,
+ .setattr = hugetlbfs_setattr,
+};
+
+static const struct inode_operations hugetlbfs_inode_operations = {
+ .setattr = hugetlbfs_setattr,
+};
+
+static const struct super_operations hugetlbfs_ops = {
+ .alloc_inode = hugetlbfs_alloc_inode,
+ .destroy_inode = hugetlbfs_destroy_inode,
+ .evict_inode = hugetlbfs_evict_inode,
+ .statfs = hugetlbfs_statfs,
+ .put_super = hugetlbfs_put_super,
+ .show_options = generic_show_options,
+};
+
+enum { 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
+hugetlbfs_size_to_hpages(struct hstate *h, unsigned long long size_opt,
+ int val_type)
+{
+ if (val_type == NO_SIZE)
+ return -1;
+
+ if (val_type == SIZE_PERCENT) {
+ size_opt <<= huge_page_shift(h);
+ size_opt *= h->max_huge_pages;
+ do_div(size_opt, 100);
+ }
+
+ size_opt >>= huge_page_shift(h);
+ return size_opt;
+}
+
+static int
+hugetlbfs_parse_options(char *options, struct hugetlbfs_config *pconfig)
+{
+ char *p, *rest;
+ 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;
+
+ if (!options)
+ return 0;
+
+ while ((p = strsep(&options, ",")) != NULL) {
+ int token;
+ if (!*p)
+ continue;
+
+ 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_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_mode:
+ if (match_octal(&args[0], &option))
+ goto bad_val;
+ pconfig->mode = option & 01777U;
+ break;
+
+ 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_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_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;
+ }
+
+ 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;
+ }
+
+ default:
+ pr_err("Bad mount option: \"%s\"\n", p);
+ return -EINVAL;
+ break;
+ }
+ }
+
+ /*
+ * 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);
+
+ /*
+ * 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");
+ 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, int silent)
+{
+ int ret;
+ 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();
+ 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;
+ /*
+ * 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 (!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_magic = HUGETLBFS_MAGIC;
+ sb->s_op = &hugetlbfs_ops;
+ sb->s_time_gran = 1;
+ sb->s_root = d_make_root(hugetlbfs_get_root(sb, &config));
+ if (!sb->s_root)
+ goto out_free;
+ return 0;
+out_free:
+ kfree(sbinfo->spool);
+ kfree(sbinfo);
+ return -ENOMEM;
+}
+
+static struct dentry *hugetlbfs_mount(struct file_system_type *fs_type,
+ int flags, const char *dev_name, void *data)
+{
+ return mount_nodev(fs_type, flags, data, hugetlbfs_fill_super);
+}
+
+static struct file_system_type hugetlbfs_fs_type = {
+ .name = "hugetlbfs",
+ .mount = hugetlbfs_mount,
+ .kill_sb = kill_litter_super,
+};
+MODULE_ALIAS_FS("hugetlbfs");
+
+static struct vfsmount *hugetlbfs_vfsmount[HUGE_MAX_HSTATE];
+
+static int can_do_hugetlb_shm(void)
+{
+ kgid_t shm_group;
+ shm_group = make_kgid(&init_user_ns, sysctl_hugetlb_shm_group);
+ return capable(CAP_IPC_LOCK) || in_group_p(shm_group);
+}
+
+static int get_hstate_idx(int page_size_log)
+{
+ struct hstate *h = hstate_sizelog(page_size_log);
+
+ if (!h)
+ return -1;
+ return h - hstates;
+}
+
+static const struct dentry_operations anon_ops = {
+ .d_dname = simple_dname
+};
+
+/*
+ * Note that size should be aligned to proper hugepage size in caller side,
+ * otherwise hugetlb_reserve_pages reserves one less hugepages than intended.
+ */
+struct file *hugetlb_file_setup(const char *name, size_t size,
+ vm_flags_t acctflag, struct user_struct **user,
+ int creat_flags, int page_size_log)
+{
+ struct file *file = ERR_PTR(-ENOMEM);
+ struct inode *inode;
+ struct path path;
+ struct super_block *sb;
+ struct qstr quick_string;
+ int hstate_idx;
+
+ hstate_idx = get_hstate_idx(page_size_log);
+ if (hstate_idx < 0)
+ return ERR_PTR(-ENODEV);
+
+ *user = NULL;
+ if (!hugetlbfs_vfsmount[hstate_idx])
+ return ERR_PTR(-ENOENT);
+
+ if (creat_flags == HUGETLB_SHMFS_INODE && !can_do_hugetlb_shm()) {
+ *user = current_user();
+ if (user_shm_lock(size, *user)) {
+ task_lock(current);
+ pr_warn_once("%s (%d): Using mlock ulimits for SHM_HUGETLB is deprecated\n",
+ current->comm, current->pid);
+ task_unlock(current);
+ } else {
+ *user = NULL;
+ return ERR_PTR(-EPERM);
+ }
+ }
+
+ sb = hugetlbfs_vfsmount[hstate_idx]->mnt_sb;
+ quick_string.name = name;
+ quick_string.len = strlen(quick_string.name);
+ quick_string.hash = 0;
+ path.dentry = d_alloc_pseudo(sb, &quick_string);
+ if (!path.dentry)
+ goto out_shm_unlock;
+
+ d_set_d_op(path.dentry, &anon_ops);
+ path.mnt = mntget(hugetlbfs_vfsmount[hstate_idx]);
+ file = ERR_PTR(-ENOSPC);
+ inode = hugetlbfs_get_inode(sb, NULL, S_IFREG | S_IRWXUGO, 0);
+ if (!inode)
+ goto out_dentry;
+
+ file = ERR_PTR(-ENOMEM);
+ if (hugetlb_reserve_pages(inode, 0,
+ size >> huge_page_shift(hstate_inode(inode)), NULL,
+ acctflag))
+ goto out_inode;
+
+ d_instantiate(path.dentry, inode);
+ inode->i_size = size;
+ clear_nlink(inode);
+
+ file = alloc_file(&path, FMODE_WRITE | FMODE_READ,
+ &hugetlbfs_file_operations);
+ if (IS_ERR(file))
+ goto out_dentry; /* inode is already attached */
+
+ return file;
+
+out_inode:
+ iput(inode);
+out_dentry:
+ path_put(&path);
+out_shm_unlock:
+ if (*user) {
+ user_shm_unlock(size, *user);
+ *user = NULL;
+ }
+ return file;
+}
+
+static int __init init_hugetlbfs_fs(void)
+{
+ struct hstate *h;
+ int error;
+ int i;
+
+ if (!hugepages_supported()) {
+ pr_info("disabling because there are no supported hugepage sizes\n");
+ return -ENOTSUPP;
+ }
+
+ error = -ENOMEM;
+ hugetlbfs_inode_cachep = kmem_cache_create("hugetlbfs_inode_cache",
+ sizeof(struct hugetlbfs_inode_info),
+ 0, 0, init_once);
+ if (hugetlbfs_inode_cachep == NULL)
+ goto out2;
+
+ error = register_filesystem(&hugetlbfs_fs_type);
+ if (error)
+ goto out;
+
+ i = 0;
+ for_each_hstate(h) {
+ char buf[50];
+ unsigned ps_kb = 1U << (h->order + PAGE_SHIFT - 10);
+
+ snprintf(buf, sizeof(buf), "pagesize=%uK", ps_kb);
+ hugetlbfs_vfsmount[i] = kern_mount_data(&hugetlbfs_fs_type,
+ buf);
+
+ 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;
+ }
+ i++;
+ }
+ /* Non default hstates are optional */
+ if (!IS_ERR_OR_NULL(hugetlbfs_vfsmount[default_hstate_idx]))
+ return 0;
+
+ out:
+ kmem_cache_destroy(hugetlbfs_inode_cachep);
+ out2:
+ return error;
+}
+
+static void __exit exit_hugetlbfs_fs(void)
+{
+ struct hstate *h;
+ int i;
+
+
+ /*
+ * Make sure all delayed rcu free inodes are flushed before we
+ * destroy cache.
+ */
+ rcu_barrier();
+ kmem_cache_destroy(hugetlbfs_inode_cachep);
+ i = 0;
+ for_each_hstate(h)
+ kern_unmount(hugetlbfs_vfsmount[i++]);
+ unregister_filesystem(&hugetlbfs_fs_type);
+}
+
+module_init(init_hugetlbfs_fs)
+module_exit(exit_hugetlbfs_fs)
+
+MODULE_LICENSE("GPL");
Code Review / kvmfornfv.git / blobdiff