linux/fs/hugetlbfs/inode.c
Mike Kravetz 70c3547e36 hugetlbfs: add hugetlbfs_fallocate()
This is based on the shmem version, but it has diverged quite a bit.  We
have no swap to worry about, nor the new file sealing.  Add
synchronication via the fault mutex table to coordinate page faults,
fallocate allocation and fallocate hole punch.

What this allows us to do is move physical memory in and out of a
hugetlbfs file without having it mapped.  This also gives us the ability
to support MADV_REMOVE since it is currently implemented using
fallocate().  MADV_REMOVE lets madvise() remove pages from the middle of
a hugetlbfs file, which wasn't possible before.

hugetlbfs fallocate only operates on whole huge pages.

Based on code by Dave Hansen.

Signed-off-by: Mike Kravetz <mike.kravetz@oracle.com>
Reviewed-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Acked-by: Hillf Danton <hillf.zj@alibaba-inc.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Aneesh Kumar <aneesh.kumar@linux.vnet.ibm.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Michal Hocko <mhocko@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-09-08 15:35:28 -07:00

1382 lines
34 KiB
C

/*
* 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/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 <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},
};
#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);
}
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;
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 remove_huge_page(struct page *page)
{
ClearPageDirty(page);
ClearPageUptodate(page);
delete_from_page_cache(page);
}
/*
* 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.
* 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.
* 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;
int i, freed = 0;
long lookup_nr = PAGEVEC_SIZE;
bool truncate_op = (lend == LLONG_MAX);
memset(&pseudo_vma, 0, sizeof(struct vm_area_struct));
pseudo_vma.vm_flags = (VM_HUGETLB | VM_MAYSHARE | VM_SHARED);
pagevec_init(&pvec, 0);
next = start;
while (next < end) {
/*
* Make sure to never grab more pages that we
* might possibly need.
*/
if (end - next < lookup_nr)
lookup_nr = end - next;
/*
* This pagevec_lookup() may return pages past 'end',
* so we must check for page->index > end.
*/
if (!pagevec_lookup(&pvec, mapping, next, lookup_nr)) {
if (next == start)
break;
next = start;
continue;
}
for (i = 0; i < pagevec_count(&pvec); ++i) {
struct page *page = pvec.pages[i];
u32 hash;
hash = hugetlb_fault_mutex_hash(h, current->mm,
&pseudo_vma,
mapping, next, 0);
mutex_lock(&hugetlb_fault_mutex_table[hash]);
lock_page(page);
if (page->index >= end) {
unlock_page(page);
mutex_unlock(&hugetlb_fault_mutex_table[hash]);
next = end; /* we are done */
break;
}
/*
* If page is mapped, it was faulted in after being
* unmapped. Do nothing in this race case. In the
* normal case page is not mapped.
*/
if (!page_mapped(page)) {
bool rsv_on_error = !PagePrivate(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. Before
* free'ing the page, note PagePrivate which
* is used in case of error.
*/
remove_huge_page(page);
freed++;
if (!truncate_op) {
if (unlikely(hugetlb_unreserve_pages(
inode, next,
next + 1, 1)))
hugetlb_fix_reserve_counts(
inode, rsv_on_error);
}
}
if (page->index > next)
next = page->index;
++next;
unlock_page(page);
mutex_unlock(&hugetlb_fault_mutex_table[hash]);
}
huge_pagevec_release(&pvec);
}
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 inline void
hugetlb_vmdelete_list(struct rb_root *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;
/*
* 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) {
end = ((end - start) << PAGE_SHIFT) +
vma->vm_start + v_offset;
if (end > vma->vm_end)
end = vma->vm_end;
} else
end = vma->vm_end;
unmap_hugepage_range(vma, vma->vm_start + v_offset, 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_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;
mutex_lock(&inode->i_mutex);
i_mmap_lock_write(mapping);
if (!RB_EMPTY_ROOT(&mapping->i_mmap))
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);
mutex_unlock(&inode->i_mutex);
}
return 0;
}
static long hugetlbfs_fallocate(struct file *file, int mode, loff_t offset,
loff_t len)
{
struct inode *inode = file_inode(file);
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;
mutex_lock(&inode->i_mutex);
/* We need to check rlimit even when FALLOC_FL_KEEP_SIZE */
error = inode_newsize_ok(inode, offset + len);
if (error)
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.
*/
memset(&pseudo_vma, 0, sizeof(struct vm_area_struct));
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, mm, &pseudo_vma, mapping,
index, addr);
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]);
/*
* page_put due to reference from alloc_huge_page()
* unlock_page because locked by add_to_page_cache()
*/
put_page(page);
unlock_page(page);
}
if (!(mode & FALLOC_FL_KEEP_SIZE) && offset + len > inode->i_size)
i_size_write(inode, offset + len);
inode->i_ctime = CURRENT_TIME;
spin_lock(&inode->i_lock);
inode->i_private = NULL;
spin_unlock(&inode->i_lock);
out:
mutex_unlock(&inode->i_mutex);
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;
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,
.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 = 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;
if (creat_flags == HUGETLB_SHMFS_INODE)
inode->i_flags |= S_PRIVATE;
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");