diff options
Diffstat (limited to 'fs/hugetlbfs/inode.c')
| -rw-r--r-- | fs/hugetlbfs/inode.c | 1114 |
1 files changed, 1114 insertions, 0 deletions
diff --git a/fs/hugetlbfs/inode.c b/fs/hugetlbfs/inode.c new file mode 100644 index 000000000..87724c1d7 --- /dev/null +++ b/fs/hugetlbfs/inode.c @@ -0,0 +1,1114 @@ +/* + * 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"); |