linux/fs/hugetlbfs/inode.c
Nadia Yvette Chambers 6d49e352ae propagate name change to comments in kernel source
I've legally changed my name with New York State, the US Social Security
Administration, et al. This patch propagates the name change and change
in initials and login to comments in the kernel source as well.

Signed-off-by: Nadia Yvette Chambers <nyc@holomorphy.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2012-12-06 10:39:54 +01:00

1065 lines
25 KiB
C

/*
* hugetlbpage-backed filesystem. Based on ramfs.
*
* Nadia Yvette Chambers, 2002
*
* Copyright (C) 2002 Linus Torvalds.
*/
#include <linux/module.h>
#include <linux/thread_info.h>
#include <asm/current.h>
#include <linux/sched.h> /* remove ASAP */
#include <linux/fs.h>
#include <linux/mount.h>
#include <linux/file.h>
#include <linux/kernel.h>
#include <linux/writeback.h>
#include <linux/pagemap.h>
#include <linux/highmem.h>
#include <linux/init.h>
#include <linux/string.h>
#include <linux/capability.h>
#include <linux/ctype.h>
#include <linux/backing-dev.h>
#include <linux/hugetlb.h>
#include <linux/pagevec.h>
#include <linux/parser.h>
#include <linux/mman.h>
#include <linux/slab.h>
#include <linux/dnotify.h>
#include <linux/statfs.h>
#include <linux/security.h>
#include <linux/magic.h>
#include <linux/migrate.h>
#include <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 nr_blocks;
long nr_inodes;
struct hstate *hstate;
};
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);
}
static struct backing_dev_info hugetlbfs_backing_dev_info = {
.name = "hugetlbfs",
.ra_pages = 0, /* No readahead */
.capabilities = BDI_CAP_NO_ACCT_AND_WRITEBACK,
};
int sysctl_hugetlb_shm_group;
enum {
Opt_size, Opt_nr_inodes,
Opt_mode, Opt_uid, Opt_gid,
Opt_pagesize,
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_err, NULL},
};
static void huge_pagevec_release(struct pagevec *pvec)
{
int i;
for (i = 0; i < pagevec_count(pvec); ++i)
put_page(pvec->pages[i]);
pagevec_reinit(pvec);
}
static int hugetlbfs_file_mmap(struct file *file, struct vm_area_struct *vma)
{
struct inode *inode = file->f_path.dentry->d_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_pgoff unwinds (may be important on powerpc
* and ia64).
*/
vma->vm_flags |= VM_HUGETLB | VM_DONTEXPAND | VM_DONTDUMP;
vma->vm_ops = &hugetlb_vm_ops;
if (vma->vm_pgoff & (~huge_page_mask(h) >> PAGE_SHIFT))
return -EINVAL;
vma_len = (loff_t)(vma->vm_end - vma->vm_start);
mutex_lock(&inode->i_mutex);
file_accessed(file);
ret = -ENOMEM;
len = vma_len + ((loff_t)vma->vm_pgoff << PAGE_SHIFT);
if (hugetlb_reserve_pages(inode,
vma->vm_pgoff >> huge_page_order(h),
len >> huge_page_shift(h), vma,
vma->vm_flags))
goto out;
ret = 0;
hugetlb_prefault_arch_hook(vma->vm_mm);
if (vma->vm_flags & VM_WRITE && inode->i_size < len)
inode->i_size = len;
out:
mutex_unlock(&inode->i_mutex);
return ret;
}
/*
* Called under down_write(mmap_sem).
*/
#ifndef HAVE_ARCH_HUGETLB_UNMAPPED_AREA
static unsigned long
hugetlb_get_unmapped_area(struct file *file, unsigned long addr,
unsigned long len, unsigned long pgoff, unsigned long flags)
{
struct mm_struct *mm = current->mm;
struct vm_area_struct *vma;
unsigned long start_addr;
struct hstate *h = hstate_file(file);
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;
}
if (len > mm->cached_hole_size)
start_addr = mm->free_area_cache;
else {
start_addr = TASK_UNMAPPED_BASE;
mm->cached_hole_size = 0;
}
full_search:
addr = ALIGN(start_addr, huge_page_size(h));
for (vma = find_vma(mm, addr); ; vma = vma->vm_next) {
/* At this point: (!vma || addr < vma->vm_end). */
if (TASK_SIZE - len < addr) {
/*
* Start a new search - just in case we missed
* some holes.
*/
if (start_addr != TASK_UNMAPPED_BASE) {
start_addr = TASK_UNMAPPED_BASE;
mm->cached_hole_size = 0;
goto full_search;
}
return -ENOMEM;
}
if (!vma || addr + len <= vma->vm_start) {
mm->free_area_cache = addr + len;
return addr;
}
if (addr + mm->cached_hole_size < vma->vm_start)
mm->cached_hole_size = vma->vm_start - addr;
addr = ALIGN(vma->vm_end, huge_page_size(h));
}
}
#endif
static int
hugetlbfs_read_actor(struct page *page, unsigned long offset,
char __user *buf, unsigned long count,
unsigned long size)
{
char *kaddr;
unsigned long left, copied = 0;
int i, chunksize;
if (size > count)
size = count;
/* Find which 4k chunk and offset with in that chunk */
i = offset >> PAGE_CACHE_SHIFT;
offset = offset & ~PAGE_CACHE_MASK;
while (size) {
chunksize = PAGE_CACHE_SIZE;
if (offset)
chunksize -= offset;
if (chunksize > size)
chunksize = size;
kaddr = kmap(&page[i]);
left = __copy_to_user(buf, kaddr + offset, chunksize);
kunmap(&page[i]);
if (left) {
copied += (chunksize - left);
break;
}
offset = 0;
size -= chunksize;
buf += chunksize;
copied += chunksize;
i++;
}
return copied ? copied : -EFAULT;
}
/*
* 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(struct file *filp, char __user *buf,
size_t len, loff_t *ppos)
{
struct hstate *h = hstate_file(filp);
struct address_space *mapping = filp->f_mapping;
struct inode *inode = mapping->host;
unsigned long index = *ppos >> huge_page_shift(h);
unsigned long offset = *ppos & ~huge_page_mask(h);
unsigned long end_index;
loff_t isize;
ssize_t retval = 0;
/* validate length */
if (len == 0)
goto out;
for (;;) {
struct page *page;
unsigned long nr, ret;
int ra;
/* nr is the maximum number of bytes to copy from this page */
nr = huge_page_size(h);
isize = i_size_read(inode);
if (!isize)
goto out;
end_index = (isize - 1) >> huge_page_shift(h);
if (index >= end_index) {
if (index > end_index)
goto out;
nr = ((isize - 1) & ~huge_page_mask(h)) + 1;
if (nr <= offset)
goto out;
}
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.
*/
ret = len < nr ? len : nr;
if (clear_user(buf, ret))
ra = -EFAULT;
else
ra = 0;
} else {
unlock_page(page);
/*
* We have the page, copy it to user space buffer.
*/
ra = hugetlbfs_read_actor(page, offset, buf, len, nr);
ret = ra;
page_cache_release(page);
}
if (ra < 0) {
if (retval == 0)
retval = ra;
goto out;
}
offset += ret;
retval += ret;
len -= ret;
index += offset >> huge_page_shift(h);
offset &= ~huge_page_mask(h);
/* short read or no more work */
if ((ret != nr) || (len == 0))
break;
}
out:
*ppos = ((loff_t)index << huge_page_shift(h)) + offset;
return retval;
}
static int hugetlbfs_write_begin(struct file *file,
struct address_space *mapping,
loff_t pos, unsigned len, unsigned flags,
struct page **pagep, void **fsdata)
{
return -EINVAL;
}
static int hugetlbfs_write_end(struct file *file, struct address_space *mapping,
loff_t pos, unsigned len, unsigned copied,
struct page *page, void *fsdata)
{
BUG();
return -EINVAL;
}
static void truncate_huge_page(struct page *page)
{
cancel_dirty_page(page, /* No IO accounting for huge pages? */0);
ClearPageUptodate(page);
delete_from_page_cache(page);
}
static void truncate_hugepages(struct inode *inode, loff_t lstart)
{
struct hstate *h = hstate_inode(inode);
struct address_space *mapping = &inode->i_data;
const pgoff_t start = lstart >> huge_page_shift(h);
struct pagevec pvec;
pgoff_t next;
int i, freed = 0;
pagevec_init(&pvec, 0);
next = start;
while (1) {
if (!pagevec_lookup(&pvec, mapping, next, PAGEVEC_SIZE)) {
if (next == start)
break;
next = start;
continue;
}
for (i = 0; i < pagevec_count(&pvec); ++i) {
struct page *page = pvec.pages[i];
lock_page(page);
if (page->index > next)
next = page->index;
++next;
truncate_huge_page(page);
unlock_page(page);
freed++;
}
huge_pagevec_release(&pvec);
}
BUG_ON(!lstart && mapping->nrpages);
hugetlb_unreserve_pages(inode, start, freed);
}
static void hugetlbfs_evict_inode(struct inode *inode)
{
truncate_hugepages(inode, 0);
clear_inode(inode);
}
static inline void
hugetlb_vmtruncate_list(struct rb_root *root, pgoff_t pgoff)
{
struct vm_area_struct *vma;
vma_interval_tree_foreach(vma, root, pgoff, ULONG_MAX) {
unsigned long v_offset;
/*
* Can the expression below overflow on 32-bit arches?
* No, because the interval tree returns us only those vmas
* which overlap the truncated area starting at pgoff,
* and no vma on a 32-bit arch can span beyond the 4GB.
*/
if (vma->vm_pgoff < pgoff)
v_offset = (pgoff - vma->vm_pgoff) << PAGE_SHIFT;
else
v_offset = 0;
unmap_hugepage_range(vma, vma->vm_start + v_offset,
vma->vm_end, NULL);
}
}
static int hugetlb_vmtruncate(struct inode *inode, loff_t offset)
{
pgoff_t pgoff;
struct address_space *mapping = inode->i_mapping;
struct hstate *h = hstate_inode(inode);
BUG_ON(offset & ~huge_page_mask(h));
pgoff = offset >> PAGE_SHIFT;
i_size_write(inode, offset);
mutex_lock(&mapping->i_mmap_mutex);
if (!RB_EMPTY_ROOT(&mapping->i_mmap))
hugetlb_vmtruncate_list(&mapping->i_mmap, pgoff);
mutex_unlock(&mapping->i_mmap_mutex);
truncate_hugepages(inode, offset);
return 0;
}
static int hugetlbfs_setattr(struct dentry *dentry, struct iattr *attr)
{
struct inode *inode = dentry->d_inode;
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;
}
static struct inode *hugetlbfs_get_inode(struct super_block *sb,
struct inode *dir,
umode_t mode, dev_t dev)
{
struct inode *inode;
inode = new_inode(sb);
if (inode) {
struct hugetlbfs_inode_info *info;
inode->i_ino = get_next_ino();
inode_init_owner(inode, dir, mode);
inode->i_mapping->a_ops = &hugetlbfs_aops;
inode->i_mapping->backing_dev_info =&hugetlbfs_backing_dev_info;
inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
INIT_LIST_HEAD(&inode->i_mapping->private_list);
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);
}
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)
return rc;
migrate_page_copy(newpage, page);
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(dentry->d_inode);
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 = hugetlbfs_read,
.mmap = hugetlbfs_file_mmap,
.fsync = noop_fsync,
.get_unmapped_area = hugetlb_get_unmapped_area,
.llseek = default_llseek,
};
static const struct inode_operations hugetlbfs_dir_inode_operations = {
.create = hugetlbfs_create,
.lookup = simple_lookup,
.link = simple_link,
.unlink = simple_unlink,
.symlink = hugetlbfs_symlink,
.mkdir = hugetlbfs_mkdir,
.rmdir = simple_rmdir,
.mknod = hugetlbfs_mknod,
.rename = simple_rename,
.setattr = hugetlbfs_setattr,
};
static const struct inode_operations hugetlbfs_inode_operations = {
.setattr = hugetlbfs_setattr,
};
static const struct super_operations hugetlbfs_ops = {
.alloc_inode = hugetlbfs_alloc_inode,
.destroy_inode = hugetlbfs_destroy_inode,
.evict_inode = hugetlbfs_evict_inode,
.statfs = hugetlbfs_statfs,
.put_super = hugetlbfs_put_super,
.show_options = generic_show_options,
};
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 size = 0;
enum { NO_SIZE, SIZE_STD, SIZE_PERCENT } setsize = 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;
size = memparse(args[0].from, &rest);
setsize = SIZE_STD;
if (*rest == '%')
setsize = 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) {
printk(KERN_ERR
"hugetlbfs: Unsupported page size %lu MB\n",
ps >> 20);
return -EINVAL;
}
break;
}
default:
printk(KERN_ERR "hugetlbfs: Bad mount option: \"%s\"\n",
p);
return -EINVAL;
break;
}
}
/* Do size after hstate is set up */
if (setsize > NO_SIZE) {
struct hstate *h = pconfig->hstate;
if (setsize == SIZE_PERCENT) {
size <<= huge_page_shift(h);
size *= h->max_huge_pages;
do_div(size, 100);
}
pconfig->nr_blocks = (size >> huge_page_shift(h));
}
return 0;
bad_val:
printk(KERN_ERR "hugetlbfs: 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.nr_blocks = -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;
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;
if (config.nr_blocks != -1) {
sbinfo->spool = hugepage_new_subpool(config.nr_blocks);
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:
if (sbinfo->spool)
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;
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);
}
struct file *hugetlb_file_setup(const char *name, unsigned long addr,
size_t size, vm_flags_t acctflag,
struct user_struct **user, int creat_flags)
{
int error = -ENOMEM;
struct file *file;
struct inode *inode;
struct path path;
struct dentry *root;
struct qstr quick_string;
struct hstate *hstate;
unsigned long num_pages;
*user = NULL;
if (!hugetlbfs_vfsmount)
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);
printk_once(KERN_WARNING
"%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);
}
}
root = hugetlbfs_vfsmount->mnt_root;
quick_string.name = name;
quick_string.len = strlen(quick_string.name);
quick_string.hash = 0;
path.dentry = d_alloc(root, &quick_string);
if (!path.dentry)
goto out_shm_unlock;
path.mnt = mntget(hugetlbfs_vfsmount);
error = -ENOSPC;
inode = hugetlbfs_get_inode(root->d_sb, NULL, S_IFREG | S_IRWXUGO, 0);
if (!inode)
goto out_dentry;
hstate = hstate_inode(inode);
size += addr & ~huge_page_mask(hstate);
num_pages = ALIGN(size, huge_page_size(hstate)) >>
huge_page_shift(hstate);
error = -ENOMEM;
if (hugetlb_reserve_pages(inode, 0, num_pages, NULL, acctflag))
goto out_inode;
d_instantiate(path.dentry, inode);
inode->i_size = size;
clear_nlink(inode);
error = -ENFILE;
file = alloc_file(&path, FMODE_WRITE | FMODE_READ,
&hugetlbfs_file_operations);
if (!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 ERR_PTR(error);
}
static int __init init_hugetlbfs_fs(void)
{
int error;
struct vfsmount *vfsmount;
error = bdi_init(&hugetlbfs_backing_dev_info);
if (error)
return error;
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;
vfsmount = kern_mount(&hugetlbfs_fs_type);
if (!IS_ERR(vfsmount)) {
hugetlbfs_vfsmount = vfsmount;
return 0;
}
error = PTR_ERR(vfsmount);
out:
kmem_cache_destroy(hugetlbfs_inode_cachep);
out2:
bdi_destroy(&hugetlbfs_backing_dev_info);
return error;
}
static void __exit exit_hugetlbfs_fs(void)
{
/*
* Make sure all delayed rcu free inodes are flushed before we
* destroy cache.
*/
rcu_barrier();
kmem_cache_destroy(hugetlbfs_inode_cachep);
kern_unmount(hugetlbfs_vfsmount);
unregister_filesystem(&hugetlbfs_fs_type);
bdi_destroy(&hugetlbfs_backing_dev_info);
}
module_init(init_hugetlbfs_fs)
module_exit(exit_hugetlbfs_fs)
MODULE_LICENSE("GPL");