diff options
Diffstat (limited to 'fs/hugetlbfs/inode.c')
| -rw-r--r-- | fs/hugetlbfs/inode.c | 1441 |
1 files changed, 1441 insertions, 0 deletions
diff --git a/fs/hugetlbfs/inode.c b/fs/hugetlbfs/inode.c new file mode 100644 index 000000000..b313627b1 --- /dev/null +++ b/fs/hugetlbfs/inode.c @@ -0,0 +1,1441 @@ +/* + * hugetlbpage-backed filesystem. Based on ramfs. + * + * Nadia Yvette Chambers, 2002 + * + * Copyright (C) 2002 Linus Torvalds. + * License: GPL + */ + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include <linux/thread_info.h> +#include <asm/current.h> +#include <linux/sched/signal.h> /* remove ASAP */ +#include <linux/falloc.h> +#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 <linux/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 { + struct hstate *hstate; + long max_hpages; + long nr_inodes; + long min_hpages; + kuid_t uid; + kgid_t gid; + umode_t mode; +}; + +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}, +}; + +#ifdef CONFIG_NUMA +static inline void hugetlb_set_vma_policy(struct vm_area_struct *vma, + struct inode *inode, pgoff_t index) +{ + vma->vm_policy = mpol_shared_policy_lookup(&HUGETLBFS_I(inode)->policy, + index); +} + +static inline void hugetlb_drop_vma_policy(struct vm_area_struct *vma) +{ + mpol_cond_put(vma->vm_policy); +} +#else +static inline void hugetlb_set_vma_policy(struct vm_area_struct *vma, + struct inode *inode, pgoff_t index) +{ +} + +static inline void hugetlb_drop_vma_policy(struct vm_area_struct *vma) +{ +} +#endif + +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); +} + +/* + * Mask used when checking the page offset value passed in via system + * calls. This value will be converted to a loff_t which is signed. + * Therefore, we want to check the upper PAGE_SHIFT + 1 bits of the + * value. The extra bit (- 1 in the shift value) is to take the sign + * bit into account. + */ +#define PGOFF_LOFFT_MAX \ + (((1UL << (PAGE_SHIFT + 1)) - 1) << (BITS_PER_LONG - (PAGE_SHIFT + 1))) + +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; + + /* + * page based offset in vm_pgoff could be sufficiently large to + * overflow a loff_t when converted to byte offset. This can + * only happen on architectures where sizeof(loff_t) == + * sizeof(unsigned long). So, only check in those instances. + */ + if (sizeof(unsigned long) == sizeof(loff_t)) { + if (vma->vm_pgoff & PGOFF_LOFFT_MAX) + return -EINVAL; + } + + /* must be huge page aligned */ + if (vma->vm_pgoff & (~huge_page_mask(h) >> PAGE_SHIFT)) + return -EINVAL; + + vma_len = (loff_t)(vma->vm_end - vma->vm_start); + len = vma_len + ((loff_t)vma->vm_pgoff << PAGE_SHIFT); + /* check for overflow */ + if (len < vma_len) + return -EINVAL; + + inode_lock(inode); + file_accessed(file); + + ret = -ENOMEM; + 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; + if (vma->vm_flags & VM_WRITE && inode->i_size < len) + i_size_write(inode, len); +out: + inode_unlock(inode); + + 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 <= vm_start_gap(vma))) + 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_SHIFT; + offset = offset & ~PAGE_MASK; + + while (size) { + size_t n; + chunksize = PAGE_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_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); + put_page(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 remove_huge_page(struct page *page) +{ + ClearPageDirty(page); + ClearPageUptodate(page); + delete_from_page_cache(page); +} + +static void +hugetlb_vmdelete_list(struct rb_root_cached *root, pgoff_t start, pgoff_t end) +{ + struct vm_area_struct *vma; + + /* + * end == 0 indicates that the entire range after + * start should be unmapped. + */ + vma_interval_tree_foreach(vma, root, start, end ? end : ULONG_MAX) { + unsigned long v_offset; + unsigned long v_end; + + /* + * 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 < start) + v_offset = (start - vma->vm_pgoff) << PAGE_SHIFT; + else + v_offset = 0; + + if (!end) + v_end = vma->vm_end; + else { + v_end = ((end - vma->vm_pgoff) << PAGE_SHIFT) + + vma->vm_start; + if (v_end > vma->vm_end) + v_end = vma->vm_end; + } + + unmap_hugepage_range(vma, vma->vm_start + v_offset, v_end, + NULL); + } +} + +/* + * remove_inode_hugepages handles two distinct cases: truncation and hole + * punch. There are subtle differences in operation for each case. + * + * truncation is indicated by end of range being LLONG_MAX + * In this case, we first scan the range and release found pages. + * After releasing pages, hugetlb_unreserve_pages cleans up region/reserv + * maps and global counts. Page faults can not race with truncation + * in this routine. hugetlb_no_page() prevents page faults in the + * truncated range. It checks i_size before allocation, and again after + * with the page table lock for the page held. The same lock must be + * acquired to unmap a page. + * hole punch is indicated if end is not LLONG_MAX + * In the hole punch case we scan the range and release found pages. + * Only when releasing a page is the associated region/reserv map + * deleted. The region/reserv map for ranges without associated + * pages are not modified. Page faults can race with hole punch. + * This is indicated if we find a mapped page. + * Note: If the passed end of range value is beyond the end of file, but + * not LLONG_MAX this routine still performs a hole punch operation. + */ +static void remove_inode_hugepages(struct inode *inode, loff_t lstart, + loff_t lend) +{ + struct hstate *h = hstate_inode(inode); + struct address_space *mapping = &inode->i_data; + const pgoff_t start = lstart >> huge_page_shift(h); + const pgoff_t end = lend >> huge_page_shift(h); + struct vm_area_struct pseudo_vma; + struct pagevec pvec; + pgoff_t next, index; + int i, freed = 0; + bool truncate_op = (lend == LLONG_MAX); + + vma_init(&pseudo_vma, current->mm); + pseudo_vma.vm_flags = (VM_HUGETLB | VM_MAYSHARE | VM_SHARED); + pagevec_init(&pvec); + next = start; + while (next < end) { + /* + * When no more pages are found, we are done. + */ + if (!pagevec_lookup_range(&pvec, mapping, &next, end - 1)) + break; + + for (i = 0; i < pagevec_count(&pvec); ++i) { + struct page *page = pvec.pages[i]; + u32 hash; + + index = page->index; + hash = hugetlb_fault_mutex_hash(h, mapping, index); + mutex_lock(&hugetlb_fault_mutex_table[hash]); + + /* + * If page is mapped, it was faulted in after being + * unmapped in caller. Unmap (again) now after taking + * the fault mutex. The mutex will prevent faults + * until we finish removing the page. + * + * This race can only happen in the hole punch case. + * Getting here in a truncate operation is a bug. + */ + if (unlikely(page_mapped(page))) { + BUG_ON(truncate_op); + + i_mmap_lock_write(mapping); + hugetlb_vmdelete_list(&mapping->i_mmap, + index * pages_per_huge_page(h), + (index + 1) * pages_per_huge_page(h)); + i_mmap_unlock_write(mapping); + } + + lock_page(page); + /* + * We must free the huge page and remove from page + * cache (remove_huge_page) BEFORE removing the + * region/reserve map (hugetlb_unreserve_pages). In + * rare out of memory conditions, removal of the + * region/reserve map could fail. Correspondingly, + * the subpool and global reserve usage count can need + * to be adjusted. + */ + VM_BUG_ON(PagePrivate(page)); + remove_huge_page(page); + freed++; + if (!truncate_op) { + if (unlikely(hugetlb_unreserve_pages(inode, + index, index + 1, 1))) + hugetlb_fix_reserve_counts(inode); + } + + unlock_page(page); + mutex_unlock(&hugetlb_fault_mutex_table[hash]); + } + huge_pagevec_release(&pvec); + cond_resched(); + } + + if (truncate_op) + (void)hugetlb_unreserve_pages(inode, start, LONG_MAX, freed); +} + +static void hugetlbfs_evict_inode(struct inode *inode) +{ + struct resv_map *resv_map; + + remove_inode_hugepages(inode, 0, LLONG_MAX); + 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 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.rb_root)) + hugetlb_vmdelete_list(&mapping->i_mmap, pgoff, 0); + i_mmap_unlock_write(mapping); + remove_inode_hugepages(inode, offset, LLONG_MAX); + return 0; +} + +static long hugetlbfs_punch_hole(struct inode *inode, loff_t offset, loff_t len) +{ + struct hstate *h = hstate_inode(inode); + loff_t hpage_size = huge_page_size(h); + loff_t hole_start, hole_end; + + /* + * For hole punch round up the beginning offset of the hole and + * round down the end. + */ + hole_start = round_up(offset, hpage_size); + hole_end = round_down(offset + len, hpage_size); + + if (hole_end > hole_start) { + struct address_space *mapping = inode->i_mapping; + struct hugetlbfs_inode_info *info = HUGETLBFS_I(inode); + + inode_lock(inode); + + /* protected by i_mutex */ + if (info->seals & F_SEAL_WRITE) { + inode_unlock(inode); + return -EPERM; + } + + i_mmap_lock_write(mapping); + if (!RB_EMPTY_ROOT(&mapping->i_mmap.rb_root)) + hugetlb_vmdelete_list(&mapping->i_mmap, + hole_start >> PAGE_SHIFT, + hole_end >> PAGE_SHIFT); + i_mmap_unlock_write(mapping); + remove_inode_hugepages(inode, hole_start, hole_end); + inode_unlock(inode); + } + + return 0; +} + +static long hugetlbfs_fallocate(struct file *file, int mode, loff_t offset, + loff_t len) +{ + struct inode *inode = file_inode(file); + struct hugetlbfs_inode_info *info = HUGETLBFS_I(inode); + struct address_space *mapping = inode->i_mapping; + struct hstate *h = hstate_inode(inode); + struct vm_area_struct pseudo_vma; + struct mm_struct *mm = current->mm; + loff_t hpage_size = huge_page_size(h); + unsigned long hpage_shift = huge_page_shift(h); + pgoff_t start, index, end; + int error; + u32 hash; + + if (mode & ~(FALLOC_FL_KEEP_SIZE | FALLOC_FL_PUNCH_HOLE)) + return -EOPNOTSUPP; + + if (mode & FALLOC_FL_PUNCH_HOLE) + return hugetlbfs_punch_hole(inode, offset, len); + + /* + * Default preallocate case. + * For this range, start is rounded down and end is rounded up + * as well as being converted to page offsets. + */ + start = offset >> hpage_shift; + end = (offset + len + hpage_size - 1) >> hpage_shift; + + inode_lock(inode); + + /* We need to check rlimit even when FALLOC_FL_KEEP_SIZE */ + error = inode_newsize_ok(inode, offset + len); + if (error) + goto out; + + if ((info->seals & F_SEAL_GROW) && offset + len > inode->i_size) { + error = -EPERM; + goto out; + } + + /* + * Initialize a pseudo vma as this is required by the huge page + * allocation routines. If NUMA is configured, use page index + * as input to create an allocation policy. + */ + vma_init(&pseudo_vma, mm); + pseudo_vma.vm_flags = (VM_HUGETLB | VM_MAYSHARE | VM_SHARED); + pseudo_vma.vm_file = file; + + for (index = start; index < end; index++) { + /* + * This is supposed to be the vaddr where the page is being + * faulted in, but we have no vaddr here. + */ + struct page *page; + unsigned long addr; + int avoid_reserve = 0; + + cond_resched(); + + /* + * fallocate(2) manpage permits EINTR; we may have been + * interrupted because we are using up too much memory. + */ + if (signal_pending(current)) { + error = -EINTR; + break; + } + + /* Set numa allocation policy based on index */ + hugetlb_set_vma_policy(&pseudo_vma, inode, index); + + /* addr is the offset within the file (zero based) */ + addr = index * hpage_size; + + /* mutex taken here, fault path and hole punch */ + hash = hugetlb_fault_mutex_hash(h, mapping, index); + mutex_lock(&hugetlb_fault_mutex_table[hash]); + + /* See if already present in mapping to avoid alloc/free */ + page = find_get_page(mapping, index); + if (page) { + put_page(page); + mutex_unlock(&hugetlb_fault_mutex_table[hash]); + hugetlb_drop_vma_policy(&pseudo_vma); + continue; + } + + /* Allocate page and add to page cache */ + page = alloc_huge_page(&pseudo_vma, addr, avoid_reserve); + hugetlb_drop_vma_policy(&pseudo_vma); + if (IS_ERR(page)) { + mutex_unlock(&hugetlb_fault_mutex_table[hash]); + error = PTR_ERR(page); + goto out; + } + clear_huge_page(page, addr, pages_per_huge_page(h)); + __SetPageUptodate(page); + error = huge_add_to_page_cache(page, mapping, index); + if (unlikely(error)) { + put_page(page); + mutex_unlock(&hugetlb_fault_mutex_table[hash]); + goto out; + } + + mutex_unlock(&hugetlb_fault_mutex_table[hash]); + + set_page_huge_active(page); + /* + * unlock_page because locked by add_to_page_cache() + * put_page() due to reference from alloc_huge_page() + */ + unlock_page(page); + put_page(page); + } + + if (!(mode & FALLOC_FL_KEEP_SIZE) && offset + len > inode->i_size) + i_size_write(inode, offset + len); + inode->i_ctime = current_time(inode); +out: + inode_unlock(inode); + return error; +} + +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; + struct hugetlbfs_inode_info *info = HUGETLBFS_I(inode); + + BUG_ON(!inode); + + error = setattr_prepare(dentry, attr); + if (error) + return error; + + if (ia_valid & ATTR_SIZE) { + loff_t oldsize = inode->i_size; + loff_t newsize = attr->ia_size; + + if (newsize & ~huge_page_mask(h)) + return -EINVAL; + /* protected by i_mutex */ + if ((newsize < oldsize && (info->seals & F_SEAL_SHRINK)) || + (newsize > oldsize && (info->seals & F_SEAL_GROW))) + return -EPERM; + error = hugetlb_vmtruncate(inode, newsize); + 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) { + 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(inode); + 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 hugetlb's + * 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 = NULL; + + /* + * Reserve maps are only needed for inodes that can have associated + * page allocations. + */ + if (S_ISREG(mode) || S_ISLNK(mode)) { + resv_map = resv_map_alloc(); + if (!resv_map) + return NULL; + } + + inode = new_inode(sb); + if (inode) { + struct hugetlbfs_inode_info *info = HUGETLBFS_I(inode); + + 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); + inode->i_mapping->private_data = resv_map; + info->seals = F_SEAL_SEAL; + 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; + inode_nohighmem(inode); + break; + } + lockdep_annotate_inode_mutex_key(inode); + } else { + if (resv_map) + 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(dir); + 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(dir); + + 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; + + /* + * page_private is subpool pointer in hugetlb pages. Transfer to + * new page. PagePrivate is not associated with page_private for + * hugetlb pages and can not be set here as only page_huge_active + * pages can be migrated. + */ + if (page_private(page)) { + set_page_private(newpage, page_private(page)); + set_page_private(page, 0); + } + + if (mode != MIGRATE_SYNC_NO_COPY) + migrate_page_copy(newpage, page); + else + migrate_page_states(newpage, page); + + return MIGRATEPAGE_SUCCESS; +} + +static int hugetlbfs_error_remove_page(struct address_space *mapping, + struct page *page) +{ + struct inode *inode = mapping->host; + pgoff_t index = page->index; + + remove_huge_page(page); + if (unlikely(hugetlb_unreserve_pages(inode, index, index + 1, 1))) + hugetlb_fix_reserve_counts(inode); + + return 0; +} + +/* + * 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); + 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; + } + + /* + * Any time after allocation, hugetlbfs_destroy_inode can be called + * for the inode. mpol_free_shared_policy is unconditionally called + * as part of hugetlbfs_destroy_inode. So, initialize policy here + * in case of a quick call to destroy. + * + * Note that the policy is initialized even if we are creating a + * private inode. This simplifies hugetlbfs_destroy_inode. + */ + mpol_shared_policy_init(&p->policy, 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, + .error_remove_page = hugetlbfs_error_remove_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, + .fallocate = hugetlbfs_fallocate, +}; + +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 = 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 + * (val_type == SIZE_STD) or percentage of the pool (val_type == SIZE_PERCENT). + */ +static long +hugetlbfs_size_to_hpages(struct hstate *h, unsigned long long size_opt, + enum hugetlbfs_size_type 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; + enum hugetlbfs_size_type 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; + + 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; + + /* + * 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, +}; + +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; +} + +/* + * 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 inode *inode; + struct vfsmount *mnt; + int hstate_idx; + struct file *file; + + hstate_idx = get_hstate_idx(page_size_log); + if (hstate_idx < 0) + return ERR_PTR(-ENODEV); + + *user = NULL; + mnt = hugetlbfs_vfsmount[hstate_idx]; + if (!mnt) + 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); + } + } + + file = ERR_PTR(-ENOSPC); + inode = hugetlbfs_get_inode(mnt->mnt_sb, NULL, S_IFREG | S_IRWXUGO, 0); + if (!inode) + goto out; + if (creat_flags == HUGETLB_SHMFS_INODE) + inode->i_flags |= S_PRIVATE; + + inode->i_size = size; + clear_nlink(inode); + + if (hugetlb_reserve_pages(inode, 0, + size >> huge_page_shift(hstate_inode(inode)), NULL, + acctflag)) + file = ERR_PTR(-ENOMEM); + else + file = alloc_file_pseudo(inode, mnt, name, O_RDWR, + &hugetlbfs_file_operations); + if (!IS_ERR(file)) + return file; + + iput(inode); +out: + 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, SLAB_ACCOUNT, 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; +} +fs_initcall(init_hugetlbfs_fs) |