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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
commit2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch)
tree848558de17fb3008cdf4d861b01ac7781903ce39 /fs/hugetlbfs
parentInitial commit. (diff)
downloadlinux-2c3c1048746a4622d8c89a29670120dc8fab93c4.tar.xz
linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.zip
Adding upstream version 6.1.76.upstream/6.1.76
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'fs/hugetlbfs')
-rw-r--r--fs/hugetlbfs/Makefile8
-rw-r--r--fs/hugetlbfs/inode.c1705
2 files changed, 1713 insertions, 0 deletions
diff --git a/fs/hugetlbfs/Makefile b/fs/hugetlbfs/Makefile
new file mode 100644
index 000000000..d876ecfbe
--- /dev/null
+++ b/fs/hugetlbfs/Makefile
@@ -0,0 +1,8 @@
+# SPDX-License-Identifier: GPL-2.0-only
+#
+# Makefile for the linux ramfs routines.
+#
+
+obj-$(CONFIG_HUGETLBFS) += hugetlbfs.o
+
+hugetlbfs-objs := inode.o
diff --git a/fs/hugetlbfs/inode.c b/fs/hugetlbfs/inode.c
new file mode 100644
index 000000000..8eea709e3
--- /dev/null
+++ b/fs/hugetlbfs/inode.c
@@ -0,0 +1,1705 @@
+/*
+ * 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/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/fs_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>
+#include <linux/sched/mm.h>
+
+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;
+
+enum hugetlbfs_size_type { NO_SIZE, SIZE_STD, SIZE_PERCENT };
+
+struct hugetlbfs_fs_context {
+ struct hstate *hstate;
+ unsigned long long max_size_opt;
+ unsigned long long min_size_opt;
+ long max_hpages;
+ long nr_inodes;
+ long min_hpages;
+ enum hugetlbfs_size_type max_val_type;
+ enum hugetlbfs_size_type min_val_type;
+ kuid_t uid;
+ kgid_t gid;
+ umode_t mode;
+};
+
+int sysctl_hugetlb_shm_group;
+
+enum hugetlb_param {
+ Opt_gid,
+ Opt_min_size,
+ Opt_mode,
+ Opt_nr_inodes,
+ Opt_pagesize,
+ Opt_size,
+ Opt_uid,
+};
+
+static const struct fs_parameter_spec hugetlb_fs_parameters[] = {
+ fsparam_u32 ("gid", Opt_gid),
+ fsparam_string("min_size", Opt_min_size),
+ fsparam_u32oct("mode", Opt_mode),
+ fsparam_string("nr_inodes", Opt_nr_inodes),
+ fsparam_string("pagesize", Opt_pagesize),
+ fsparam_string("size", Opt_size),
+ fsparam_u32 ("uid", Opt_uid),
+ {}
+};
+
+#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
+
+/*
+ * 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);
+ struct hugetlbfs_inode_info *info = HUGETLBFS_I(inode);
+ 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 unwinds (may be important on powerpc
+ * and ia64).
+ */
+ vma->vm_flags |= VM_HUGETLB | VM_DONTEXPAND;
+ vma->vm_ops = &hugetlb_vm_ops;
+
+ ret = seal_check_future_write(info->seals, vma);
+ if (ret)
+ return ret;
+
+ /*
+ * 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 mmap_write_lock(mm).
+ */
+
+static unsigned long
+hugetlb_get_unmapped_area_bottomup(struct file *file, unsigned long addr,
+ unsigned long len, unsigned long pgoff, unsigned long flags)
+{
+ struct hstate *h = hstate_file(file);
+ struct vm_unmapped_area_info info;
+
+ info.flags = 0;
+ info.length = len;
+ info.low_limit = current->mm->mmap_base;
+ info.high_limit = arch_get_mmap_end(addr, len, flags);
+ info.align_mask = PAGE_MASK & ~huge_page_mask(h);
+ info.align_offset = 0;
+ return vm_unmapped_area(&info);
+}
+
+static unsigned long
+hugetlb_get_unmapped_area_topdown(struct file *file, unsigned long addr,
+ unsigned long len, unsigned long pgoff, unsigned long flags)
+{
+ struct hstate *h = hstate_file(file);
+ struct vm_unmapped_area_info info;
+
+ info.flags = VM_UNMAPPED_AREA_TOPDOWN;
+ info.length = len;
+ info.low_limit = max(PAGE_SIZE, mmap_min_addr);
+ info.high_limit = arch_get_mmap_base(addr, current->mm->mmap_base);
+ info.align_mask = PAGE_MASK & ~huge_page_mask(h);
+ info.align_offset = 0;
+ addr = vm_unmapped_area(&info);
+
+ /*
+ * A failed mmap() very likely causes application failure,
+ * so fall back to the bottom-up function here. This scenario
+ * can happen with large stack limits and large mmap()
+ * allocations.
+ */
+ if (unlikely(offset_in_page(addr))) {
+ VM_BUG_ON(addr != -ENOMEM);
+ info.flags = 0;
+ info.low_limit = current->mm->mmap_base;
+ info.high_limit = arch_get_mmap_end(addr, len, flags);
+ addr = vm_unmapped_area(&info);
+ }
+
+ return addr;
+}
+
+unsigned long
+generic_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);
+ const unsigned long mmap_end = arch_get_mmap_end(addr, len, flags);
+
+ 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 (mmap_end - len >= addr &&
+ (!vma || addr + len <= vm_start_gap(vma)))
+ return addr;
+ }
+
+ /*
+ * Use mm->get_unmapped_area value as a hint to use topdown routine.
+ * If architectures have special needs, they should define their own
+ * version of hugetlb_get_unmapped_area.
+ */
+ if (mm->get_unmapped_area == arch_get_unmapped_area_topdown)
+ return hugetlb_get_unmapped_area_topdown(file, addr, len,
+ pgoff, flags);
+ return hugetlb_get_unmapped_area_bottomup(file, addr, len,
+ pgoff, flags);
+}
+
+#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)
+{
+ return generic_hugetlb_get_unmapped_area(file, addr, len, pgoff, flags);
+}
+#endif
+
+/*
+ * Support for read() - Find the page attached to f_mapping and copy out the
+ * data. This provides functionality similar to filemap_read().
+ */
+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);
+
+ if (PageHWPoison(page)) {
+ put_page(page);
+ retval = -EIO;
+ break;
+ }
+
+ /*
+ * We have the page, copy it to user space buffer.
+ */
+ copied = copy_page_to_iter(page, offset, nr, to);
+ 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,
+ 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 hugetlb_delete_from_page_cache(struct page *page)
+{
+ ClearPageDirty(page);
+ ClearPageUptodate(page);
+ delete_from_page_cache(page);
+}
+
+/*
+ * Called with i_mmap_rwsem held for inode based vma maps. This makes
+ * sure vma (and vm_mm) will not go away. We also hold the hugetlb fault
+ * mutex for the page in the mapping. So, we can not race with page being
+ * faulted into the vma.
+ */
+static bool hugetlb_vma_maps_page(struct vm_area_struct *vma,
+ unsigned long addr, struct page *page)
+{
+ pte_t *ptep, pte;
+
+ ptep = huge_pte_offset(vma->vm_mm, addr,
+ huge_page_size(hstate_vma(vma)));
+
+ if (!ptep)
+ return false;
+
+ pte = huge_ptep_get(ptep);
+ if (huge_pte_none(pte) || !pte_present(pte))
+ return false;
+
+ if (pte_page(pte) == page)
+ return true;
+
+ return false;
+}
+
+/*
+ * Can vma_offset_start/vma_offset_end 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.
+ */
+static unsigned long vma_offset_start(struct vm_area_struct *vma, pgoff_t start)
+{
+ if (vma->vm_pgoff < start)
+ return (start - vma->vm_pgoff) << PAGE_SHIFT;
+ else
+ return 0;
+}
+
+static unsigned long vma_offset_end(struct vm_area_struct *vma, pgoff_t end)
+{
+ unsigned long t_end;
+
+ if (!end)
+ return vma->vm_end;
+
+ t_end = ((end - vma->vm_pgoff) << PAGE_SHIFT) + vma->vm_start;
+ if (t_end > vma->vm_end)
+ t_end = vma->vm_end;
+ return t_end;
+}
+
+/*
+ * Called with hugetlb fault mutex held. Therefore, no more mappings to
+ * this folio can be created while executing the routine.
+ */
+static void hugetlb_unmap_file_folio(struct hstate *h,
+ struct address_space *mapping,
+ struct folio *folio, pgoff_t index)
+{
+ struct rb_root_cached *root = &mapping->i_mmap;
+ struct hugetlb_vma_lock *vma_lock;
+ struct page *page = &folio->page;
+ struct vm_area_struct *vma;
+ unsigned long v_start;
+ unsigned long v_end;
+ pgoff_t start, end;
+
+ start = index * pages_per_huge_page(h);
+ end = (index + 1) * pages_per_huge_page(h);
+
+ i_mmap_lock_write(mapping);
+retry:
+ vma_lock = NULL;
+ vma_interval_tree_foreach(vma, root, start, end - 1) {
+ v_start = vma_offset_start(vma, start);
+ v_end = vma_offset_end(vma, end);
+
+ if (!hugetlb_vma_maps_page(vma, vma->vm_start + v_start, page))
+ continue;
+
+ if (!hugetlb_vma_trylock_write(vma)) {
+ vma_lock = vma->vm_private_data;
+ /*
+ * If we can not get vma lock, we need to drop
+ * immap_sema and take locks in order. First,
+ * take a ref on the vma_lock structure so that
+ * we can be guaranteed it will not go away when
+ * dropping immap_sema.
+ */
+ kref_get(&vma_lock->refs);
+ break;
+ }
+
+ unmap_hugepage_range(vma, vma->vm_start + v_start, v_end,
+ NULL, ZAP_FLAG_DROP_MARKER);
+ hugetlb_vma_unlock_write(vma);
+ }
+
+ i_mmap_unlock_write(mapping);
+
+ if (vma_lock) {
+ /*
+ * Wait on vma_lock. We know it is still valid as we have
+ * a reference. We must 'open code' vma locking as we do
+ * not know if vma_lock is still attached to vma.
+ */
+ down_write(&vma_lock->rw_sema);
+ i_mmap_lock_write(mapping);
+
+ vma = vma_lock->vma;
+ if (!vma) {
+ /*
+ * If lock is no longer attached to vma, then just
+ * unlock, drop our reference and retry looking for
+ * other vmas.
+ */
+ up_write(&vma_lock->rw_sema);
+ kref_put(&vma_lock->refs, hugetlb_vma_lock_release);
+ goto retry;
+ }
+
+ /*
+ * vma_lock is still attached to vma. Check to see if vma
+ * still maps page and if so, unmap.
+ */
+ v_start = vma_offset_start(vma, start);
+ v_end = vma_offset_end(vma, end);
+ if (hugetlb_vma_maps_page(vma, vma->vm_start + v_start, page))
+ unmap_hugepage_range(vma, vma->vm_start + v_start,
+ v_end, NULL,
+ ZAP_FLAG_DROP_MARKER);
+
+ kref_put(&vma_lock->refs, hugetlb_vma_lock_release);
+ hugetlb_vma_unlock_write(vma);
+
+ goto retry;
+ }
+}
+
+static void
+hugetlb_vmdelete_list(struct rb_root_cached *root, pgoff_t start, pgoff_t end,
+ zap_flags_t zap_flags)
+{
+ struct vm_area_struct *vma;
+
+ /*
+ * end == 0 indicates that the entire range after start should be
+ * unmapped. Note, end is exclusive, whereas the interval tree takes
+ * an inclusive "last".
+ */
+ vma_interval_tree_foreach(vma, root, start, end ? end - 1 : ULONG_MAX) {
+ unsigned long v_start;
+ unsigned long v_end;
+
+ if (!hugetlb_vma_trylock_write(vma))
+ continue;
+
+ v_start = vma_offset_start(vma, start);
+ v_end = vma_offset_end(vma, end);
+
+ unmap_hugepage_range(vma, vma->vm_start + v_start, v_end,
+ NULL, zap_flags);
+
+ /*
+ * Note that vma lock only exists for shared/non-private
+ * vmas. Therefore, lock is not held when calling
+ * unmap_hugepage_range for private vmas.
+ */
+ hugetlb_vma_unlock_write(vma);
+ }
+}
+
+/*
+ * Called with hugetlb fault mutex held.
+ * Returns true if page was actually removed, false otherwise.
+ */
+static bool remove_inode_single_folio(struct hstate *h, struct inode *inode,
+ struct address_space *mapping,
+ struct folio *folio, pgoff_t index,
+ bool truncate_op)
+{
+ bool ret = false;
+
+ /*
+ * If folio is mapped, it was faulted in after being
+ * unmapped in caller. Unmap (again) while holding
+ * the fault mutex. The mutex will prevent faults
+ * until we finish removing the folio.
+ */
+ if (unlikely(folio_mapped(folio)))
+ hugetlb_unmap_file_folio(h, mapping, folio, index);
+
+ folio_lock(folio);
+ /*
+ * We must remove the folio from page cache 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(HPageRestoreReserve(&folio->page));
+ hugetlb_delete_from_page_cache(&folio->page);
+ ret = true;
+ if (!truncate_op) {
+ if (unlikely(hugetlb_unreserve_pages(inode, index,
+ index + 1, 1)))
+ hugetlb_fix_reserve_counts(inode);
+ }
+
+ folio_unlock(folio);
+ return ret;
+}
+
+/*
+ * 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/reserve
+ * maps and global counts. Page faults can race with truncation.
+ * During faults, hugetlb_no_page() checks i_size before page allocation,
+ * and again after obtaining page table lock. It will 'back out'
+ * allocations in the truncated range.
+ * 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/reserve map
+ * deleted. The region/reserve 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 folio_batch fbatch;
+ pgoff_t next, index;
+ int i, freed = 0;
+ bool truncate_op = (lend == LLONG_MAX);
+
+ folio_batch_init(&fbatch);
+ next = start;
+ while (filemap_get_folios(mapping, &next, end - 1, &fbatch)) {
+ for (i = 0; i < folio_batch_count(&fbatch); ++i) {
+ struct folio *folio = fbatch.folios[i];
+ u32 hash = 0;
+
+ index = folio->index;
+ hash = hugetlb_fault_mutex_hash(mapping, index);
+ mutex_lock(&hugetlb_fault_mutex_table[hash]);
+
+ /*
+ * Remove folio that was part of folio_batch.
+ */
+ if (remove_inode_single_folio(h, inode, mapping, folio,
+ index, truncate_op))
+ freed++;
+
+ mutex_unlock(&hugetlb_fault_mutex_table[hash]);
+ }
+ folio_batch_release(&fbatch);
+ 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);
+
+ /*
+ * Get the resv_map from the address space embedded in the inode.
+ * This is the address space which points to any resv_map allocated
+ * at inode creation time. If this is a device special inode,
+ * i_mapping may not point to the original address space.
+ */
+ resv_map = (struct resv_map *)(&inode->i_data)->private_data;
+ /* Only regular and link inodes have associated reserve maps */
+ if (resv_map)
+ resv_map_release(&resv_map->refs);
+ clear_inode(inode);
+}
+
+static void 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,
+ ZAP_FLAG_DROP_MARKER);
+ i_mmap_unlock_write(mapping);
+ remove_inode_hugepages(inode, offset, LLONG_MAX);
+}
+
+static void hugetlbfs_zero_partial_page(struct hstate *h,
+ struct address_space *mapping,
+ loff_t start,
+ loff_t end)
+{
+ pgoff_t idx = start >> huge_page_shift(h);
+ struct folio *folio;
+
+ folio = filemap_lock_folio(mapping, idx);
+ if (!folio)
+ return;
+
+ start = start & ~huge_page_mask(h);
+ end = end & ~huge_page_mask(h);
+ if (!end)
+ end = huge_page_size(h);
+
+ folio_zero_segment(folio, (size_t)start, (size_t)end);
+
+ folio_unlock(folio);
+ folio_put(folio);
+}
+
+static long hugetlbfs_punch_hole(struct inode *inode, loff_t offset, loff_t len)
+{
+ struct hugetlbfs_inode_info *info = HUGETLBFS_I(inode);
+ struct address_space *mapping = inode->i_mapping;
+ struct hstate *h = hstate_inode(inode);
+ loff_t hpage_size = huge_page_size(h);
+ loff_t hole_start, hole_end;
+
+ /*
+ * hole_start and hole_end indicate the full pages within the hole.
+ */
+ hole_start = round_up(offset, hpage_size);
+ hole_end = round_down(offset + len, hpage_size);
+
+ inode_lock(inode);
+
+ /* protected by i_rwsem */
+ if (info->seals & (F_SEAL_WRITE | F_SEAL_FUTURE_WRITE)) {
+ inode_unlock(inode);
+ return -EPERM;
+ }
+
+ i_mmap_lock_write(mapping);
+
+ /* If range starts before first full page, zero partial page. */
+ if (offset < hole_start)
+ hugetlbfs_zero_partial_page(h, mapping,
+ offset, min(offset + len, hole_start));
+
+ /* Unmap users of full pages in the hole. */
+ if (hole_end > hole_start) {
+ if (!RB_EMPTY_ROOT(&mapping->i_mmap.rb_root))
+ hugetlb_vmdelete_list(&mapping->i_mmap,
+ hole_start >> PAGE_SHIFT,
+ hole_end >> PAGE_SHIFT, 0);
+ }
+
+ /* If range extends beyond last full page, zero partial page. */
+ if ((offset + len) > hole_end && (offset + len) > hole_start)
+ hugetlbfs_zero_partial_page(h, mapping,
+ hole_end, offset + len);
+
+ i_mmap_unlock_write(mapping);
+
+ /* Remove full pages from the file. */
+ if (hole_end > hole_start)
+ 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;
+
+ 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(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 without setting the avoid_reserve argument.
+ * There certainly are no reserves associated with the
+ * pseudo_vma. However, there could be shared mappings with
+ * reserves for the file at the inode level. If we fallocate
+ * pages in these areas, we need to consume the reserves
+ * to keep reservation accounting consistent.
+ */
+ page = alloc_huge_page(&pseudo_vma, addr, 0);
+ 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 = hugetlb_add_to_page_cache(page, mapping, index);
+ if (unlikely(error)) {
+ restore_reserve_on_error(h, &pseudo_vma, addr, page);
+ put_page(page);
+ mutex_unlock(&hugetlb_fault_mutex_table[hash]);
+ goto out;
+ }
+
+ mutex_unlock(&hugetlb_fault_mutex_table[hash]);
+
+ SetHPageMigratable(page);
+ /*
+ * unlock_page because locked by hugetlb_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 user_namespace *mnt_userns,
+ 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);
+
+ error = setattr_prepare(&init_user_ns, 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_rwsem */
+ if ((newsize < oldsize && (info->seals & F_SEAL_SHRINK)) ||
+ (newsize > oldsize && (info->seals & F_SEAL_GROW)))
+ return -EPERM;
+ hugetlb_vmtruncate(inode, newsize);
+ }
+
+ setattr_copy(&init_user_ns, inode, attr);
+ mark_inode_dirty(inode);
+ return 0;
+}
+
+static struct inode *hugetlbfs_get_root(struct super_block *sb,
+ struct hugetlbfs_fs_context *ctx)
+{
+ struct inode *inode;
+
+ inode = new_inode(sb);
+ if (inode) {
+ inode->i_ino = get_next_ino();
+ inode->i_mode = S_IFDIR | ctx->mode;
+ inode->i_uid = ctx->uid;
+ inode->i_gid = ctx->gid;
+ inode->i_atime = inode->i_mtime = inode->i_ctime = current_time(inode);
+ inode->i_op = &hugetlbfs_dir_inode_operations;
+ inode->i_fop = &simple_dir_operations;
+ /* 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(&init_user_ns, 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 user_namespace *mnt_userns, struct inode *dir,
+ struct dentry *dentry, umode_t mode, dev_t dev)
+{
+ struct inode *inode;
+
+ inode = hugetlbfs_get_inode(dir->i_sb, dir, mode, dev);
+ if (!inode)
+ return -ENOSPC;
+ dir->i_ctime = dir->i_mtime = current_time(dir);
+ d_instantiate(dentry, inode);
+ dget(dentry);/* Extra count - pin the dentry in core */
+ return 0;
+}
+
+static int hugetlbfs_mkdir(struct user_namespace *mnt_userns, struct inode *dir,
+ struct dentry *dentry, umode_t mode)
+{
+ int retval = hugetlbfs_mknod(&init_user_ns, dir, dentry,
+ mode | S_IFDIR, 0);
+ if (!retval)
+ inc_nlink(dir);
+ return retval;
+}
+
+static int hugetlbfs_create(struct user_namespace *mnt_userns,
+ struct inode *dir, struct dentry *dentry,
+ umode_t mode, bool excl)
+{
+ return hugetlbfs_mknod(&init_user_ns, dir, dentry, mode | S_IFREG, 0);
+}
+
+static int hugetlbfs_tmpfile(struct user_namespace *mnt_userns,
+ struct inode *dir, struct file *file,
+ umode_t mode)
+{
+ struct inode *inode;
+
+ inode = hugetlbfs_get_inode(dir->i_sb, dir, mode | S_IFREG, 0);
+ if (!inode)
+ return -ENOSPC;
+ dir->i_ctime = dir->i_mtime = current_time(dir);
+ d_tmpfile(file, inode);
+ return finish_open_simple(file, 0);
+}
+
+static int hugetlbfs_symlink(struct user_namespace *mnt_userns,
+ 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;
+}
+
+#ifdef CONFIG_MIGRATION
+static int hugetlbfs_migrate_folio(struct address_space *mapping,
+ struct folio *dst, struct folio *src,
+ enum migrate_mode mode)
+{
+ int rc;
+
+ rc = migrate_huge_page_move_mapping(mapping, dst, src);
+ if (rc != MIGRATEPAGE_SUCCESS)
+ return rc;
+
+ if (hugetlb_page_subpool(&src->page)) {
+ hugetlb_set_page_subpool(&dst->page,
+ hugetlb_page_subpool(&src->page));
+ hugetlb_set_page_subpool(&src->page, NULL);
+ }
+
+ if (mode != MIGRATE_SYNC_NO_COPY)
+ folio_migrate_copy(dst, src);
+ else
+ folio_migrate_flags(dst, src);
+
+ return MIGRATEPAGE_SUCCESS;
+}
+#else
+#define hugetlbfs_migrate_folio NULL
+#endif
+
+static int hugetlbfs_error_remove_page(struct address_space *mapping,
+ struct page *page)
+{
+ 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 or -1 for max/free/used
+ * blocks, like simple_statfs() */
+ if (sbinfo->spool) {
+ long free_pages;
+
+ spin_lock_irq(&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_irq(&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 = alloc_inode_sb(sb, 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_free_inode(struct inode *inode)
+{
+ 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);
+}
+
+static const struct address_space_operations hugetlbfs_aops = {
+ .write_begin = hugetlbfs_write_begin,
+ .write_end = hugetlbfs_write_end,
+ .dirty_folio = noop_dirty_folio,
+ .migrate_folio = hugetlbfs_migrate_folio,
+ .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,
+ .tmpfile = hugetlbfs_tmpfile,
+};
+
+static const struct inode_operations hugetlbfs_inode_operations = {
+ .setattr = hugetlbfs_setattr,
+};
+
+static const struct super_operations hugetlbfs_ops = {
+ .alloc_inode = hugetlbfs_alloc_inode,
+ .free_inode = hugetlbfs_free_inode,
+ .destroy_inode = hugetlbfs_destroy_inode,
+ .evict_inode = hugetlbfs_evict_inode,
+ .statfs = hugetlbfs_statfs,
+ .put_super = hugetlbfs_put_super,
+ .show_options = hugetlbfs_show_options,
+};
+
+/*
+ * 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;
+}
+
+/*
+ * Parse one mount parameter.
+ */
+static int hugetlbfs_parse_param(struct fs_context *fc, struct fs_parameter *param)
+{
+ struct hugetlbfs_fs_context *ctx = fc->fs_private;
+ struct fs_parse_result result;
+ char *rest;
+ unsigned long ps;
+ int opt;
+
+ opt = fs_parse(fc, hugetlb_fs_parameters, param, &result);
+ if (opt < 0)
+ return opt;
+
+ switch (opt) {
+ case Opt_uid:
+ ctx->uid = make_kuid(current_user_ns(), result.uint_32);
+ if (!uid_valid(ctx->uid))
+ goto bad_val;
+ return 0;
+
+ case Opt_gid:
+ ctx->gid = make_kgid(current_user_ns(), result.uint_32);
+ if (!gid_valid(ctx->gid))
+ goto bad_val;
+ return 0;
+
+ case Opt_mode:
+ ctx->mode = result.uint_32 & 01777U;
+ return 0;
+
+ case Opt_size:
+ /* memparse() will accept a K/M/G without a digit */
+ if (!param->string || !isdigit(param->string[0]))
+ goto bad_val;
+ ctx->max_size_opt = memparse(param->string, &rest);
+ ctx->max_val_type = SIZE_STD;
+ if (*rest == '%')
+ ctx->max_val_type = SIZE_PERCENT;
+ return 0;
+
+ case Opt_nr_inodes:
+ /* memparse() will accept a K/M/G without a digit */
+ if (!param->string || !isdigit(param->string[0]))
+ goto bad_val;
+ ctx->nr_inodes = memparse(param->string, &rest);
+ return 0;
+
+ case Opt_pagesize:
+ ps = memparse(param->string, &rest);
+ ctx->hstate = size_to_hstate(ps);
+ if (!ctx->hstate) {
+ pr_err("Unsupported page size %lu MB\n", ps / SZ_1M);
+ return -EINVAL;
+ }
+ return 0;
+
+ case Opt_min_size:
+ /* memparse() will accept a K/M/G without a digit */
+ if (!param->string || !isdigit(param->string[0]))
+ goto bad_val;
+ ctx->min_size_opt = memparse(param->string, &rest);
+ ctx->min_val_type = SIZE_STD;
+ if (*rest == '%')
+ ctx->min_val_type = SIZE_PERCENT;
+ return 0;
+
+ default:
+ return -EINVAL;
+ }
+
+bad_val:
+ return invalfc(fc, "Bad value '%s' for mount option '%s'\n",
+ param->string, param->key);
+}
+
+/*
+ * Validate the parsed options.
+ */
+static int hugetlbfs_validate(struct fs_context *fc)
+{
+ struct hugetlbfs_fs_context *ctx = fc->fs_private;
+
+ /*
+ * Use huge page pool size (in hstate) to convert the size
+ * options to number of huge pages. If NO_SIZE, -1 is returned.
+ */
+ ctx->max_hpages = hugetlbfs_size_to_hpages(ctx->hstate,
+ ctx->max_size_opt,
+ ctx->max_val_type);
+ ctx->min_hpages = hugetlbfs_size_to_hpages(ctx->hstate,
+ ctx->min_size_opt,
+ ctx->min_val_type);
+
+ /*
+ * If max_size was specified, then min_size must be smaller
+ */
+ if (ctx->max_val_type > NO_SIZE &&
+ ctx->min_hpages > ctx->max_hpages) {
+ pr_err("Minimum size can not be greater than maximum size\n");
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+static int
+hugetlbfs_fill_super(struct super_block *sb, struct fs_context *fc)
+{
+ struct hugetlbfs_fs_context *ctx = fc->fs_private;
+ struct hugetlbfs_sb_info *sbinfo;
+
+ sbinfo = kmalloc(sizeof(struct hugetlbfs_sb_info), GFP_KERNEL);
+ if (!sbinfo)
+ return -ENOMEM;
+ sb->s_fs_info = sbinfo;
+ spin_lock_init(&sbinfo->stat_lock);
+ sbinfo->hstate = ctx->hstate;
+ sbinfo->max_inodes = ctx->nr_inodes;
+ sbinfo->free_inodes = ctx->nr_inodes;
+ sbinfo->spool = NULL;
+ sbinfo->uid = ctx->uid;
+ sbinfo->gid = ctx->gid;
+ sbinfo->mode = ctx->mode;
+
+ /*
+ * Allocate and initialize subpool if maximum or minimum size is
+ * specified. Any needed reservations (for minimum size) are taken
+ * when the subpool is created.
+ */
+ if (ctx->max_hpages != -1 || ctx->min_hpages != -1) {
+ sbinfo->spool = hugepage_new_subpool(ctx->hstate,
+ ctx->max_hpages,
+ ctx->min_hpages);
+ if (!sbinfo->spool)
+ goto out_free;
+ }
+ sb->s_maxbytes = MAX_LFS_FILESIZE;
+ sb->s_blocksize = huge_page_size(ctx->hstate);
+ sb->s_blocksize_bits = huge_page_shift(ctx->hstate);
+ sb->s_magic = HUGETLBFS_MAGIC;
+ sb->s_op = &hugetlbfs_ops;
+ sb->s_time_gran = 1;
+
+ /*
+ * Due to the special and limited functionality of hugetlbfs, it does
+ * not work well as a stacking filesystem.
+ */
+ sb->s_stack_depth = FILESYSTEM_MAX_STACK_DEPTH;
+ sb->s_root = d_make_root(hugetlbfs_get_root(sb, ctx));
+ if (!sb->s_root)
+ goto out_free;
+ return 0;
+out_free:
+ kfree(sbinfo->spool);
+ kfree(sbinfo);
+ return -ENOMEM;
+}
+
+static int hugetlbfs_get_tree(struct fs_context *fc)
+{
+ int err = hugetlbfs_validate(fc);
+ if (err)
+ return err;
+ return get_tree_nodev(fc, hugetlbfs_fill_super);
+}
+
+static void hugetlbfs_fs_context_free(struct fs_context *fc)
+{
+ kfree(fc->fs_private);
+}
+
+static const struct fs_context_operations hugetlbfs_fs_context_ops = {
+ .free = hugetlbfs_fs_context_free,
+ .parse_param = hugetlbfs_parse_param,
+ .get_tree = hugetlbfs_get_tree,
+};
+
+static int hugetlbfs_init_fs_context(struct fs_context *fc)
+{
+ struct hugetlbfs_fs_context *ctx;
+
+ ctx = kzalloc(sizeof(struct hugetlbfs_fs_context), GFP_KERNEL);
+ if (!ctx)
+ return -ENOMEM;
+
+ ctx->max_hpages = -1; /* No limit on size by default */
+ ctx->nr_inodes = -1; /* No limit on number of inodes by default */
+ ctx->uid = current_fsuid();
+ ctx->gid = current_fsgid();
+ ctx->mode = 0755;
+ ctx->hstate = &default_hstate;
+ ctx->min_hpages = -1; /* No default minimum size */
+ ctx->max_val_type = NO_SIZE;
+ ctx->min_val_type = NO_SIZE;
+ fc->fs_private = ctx;
+ fc->ops = &hugetlbfs_fs_context_ops;
+ return 0;
+}
+
+static struct file_system_type hugetlbfs_fs_type = {
+ .name = "hugetlbfs",
+ .init_fs_context = hugetlbfs_init_fs_context,
+ .parameters = hugetlb_fs_parameters,
+ .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 hstate_index(h);
+}
+
+/*
+ * 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, 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);
+
+ mnt = hugetlbfs_vfsmount[hstate_idx];
+ if (!mnt)
+ return ERR_PTR(-ENOENT);
+
+ if (creat_flags == HUGETLB_SHMFS_INODE && !can_do_hugetlb_shm()) {
+ struct ucounts *ucounts = current_ucounts();
+
+ if (user_shm_lock(size, ucounts)) {
+ pr_warn_once("%s (%d): Using mlock ulimits for SHM_HUGETLB is obsolete\n",
+ current->comm, current->pid);
+ user_shm_unlock(size, ucounts);
+ }
+ 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:
+ return file;
+}
+
+static struct vfsmount *__init mount_one_hugetlbfs(struct hstate *h)
+{
+ struct fs_context *fc;
+ struct vfsmount *mnt;
+
+ fc = fs_context_for_mount(&hugetlbfs_fs_type, SB_KERNMOUNT);
+ if (IS_ERR(fc)) {
+ mnt = ERR_CAST(fc);
+ } else {
+ struct hugetlbfs_fs_context *ctx = fc->fs_private;
+ ctx->hstate = h;
+ mnt = fc_mount(fc);
+ put_fs_context(fc);
+ }
+ if (IS_ERR(mnt))
+ pr_err("Cannot mount internal hugetlbfs for page size %luK",
+ huge_page_size(h) / SZ_1K);
+ return mnt;
+}
+
+static int __init init_hugetlbfs_fs(void)
+{
+ struct vfsmount *mnt;
+ 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 out;
+
+ error = register_filesystem(&hugetlbfs_fs_type);
+ if (error)
+ goto out_free;
+
+ /* default hstate mount is required */
+ mnt = mount_one_hugetlbfs(&default_hstate);
+ if (IS_ERR(mnt)) {
+ error = PTR_ERR(mnt);
+ goto out_unreg;
+ }
+ hugetlbfs_vfsmount[default_hstate_idx] = mnt;
+
+ /* other hstates are optional */
+ i = 0;
+ for_each_hstate(h) {
+ if (i == default_hstate_idx) {
+ i++;
+ continue;
+ }
+
+ mnt = mount_one_hugetlbfs(h);
+ if (IS_ERR(mnt))
+ hugetlbfs_vfsmount[i] = NULL;
+ else
+ hugetlbfs_vfsmount[i] = mnt;
+ i++;
+ }
+
+ return 0;
+
+ out_unreg:
+ (void)unregister_filesystem(&hugetlbfs_fs_type);
+ out_free:
+ kmem_cache_destroy(hugetlbfs_inode_cachep);
+ out:
+ return error;
+}
+fs_initcall(init_hugetlbfs_fs)