843 lines
19 KiB
C
843 lines
19 KiB
C
/*
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* hugetlbpage-backed filesystem. Based on ramfs.
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*
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* William Irwin, 2002
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*
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* Copyright (C) 2002 Linus Torvalds.
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*/
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#include <linux/module.h>
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#include <linux/thread_info.h>
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#include <asm/current.h>
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#include <linux/sched.h> /* remove ASAP */
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#include <linux/fs.h>
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#include <linux/mount.h>
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#include <linux/file.h>
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#include <linux/writeback.h>
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#include <linux/pagemap.h>
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#include <linux/highmem.h>
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#include <linux/init.h>
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#include <linux/string.h>
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#include <linux/capability.h>
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#include <linux/backing-dev.h>
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#include <linux/hugetlb.h>
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#include <linux/pagevec.h>
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#include <linux/quotaops.h>
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#include <linux/slab.h>
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#include <linux/dnotify.h>
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#include <linux/statfs.h>
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#include <linux/security.h>
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#include <asm/uaccess.h>
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/* some random number */
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#define HUGETLBFS_MAGIC 0x958458f6
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static struct super_operations hugetlbfs_ops;
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static const struct address_space_operations hugetlbfs_aops;
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const struct file_operations hugetlbfs_file_operations;
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static struct inode_operations hugetlbfs_dir_inode_operations;
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static struct inode_operations hugetlbfs_inode_operations;
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static struct backing_dev_info hugetlbfs_backing_dev_info = {
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.ra_pages = 0, /* No readahead */
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.capabilities = BDI_CAP_NO_ACCT_DIRTY | BDI_CAP_NO_WRITEBACK,
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};
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int sysctl_hugetlb_shm_group;
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static void huge_pagevec_release(struct pagevec *pvec)
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{
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int i;
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for (i = 0; i < pagevec_count(pvec); ++i)
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put_page(pvec->pages[i]);
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pagevec_reinit(pvec);
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}
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static int hugetlbfs_file_mmap(struct file *file, struct vm_area_struct *vma)
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{
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struct inode *inode = file->f_dentry->d_inode;
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loff_t len, vma_len;
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int ret;
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if (vma->vm_pgoff & (HPAGE_SIZE / PAGE_SIZE - 1))
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return -EINVAL;
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if (vma->vm_start & ~HPAGE_MASK)
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return -EINVAL;
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if (vma->vm_end & ~HPAGE_MASK)
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return -EINVAL;
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if (vma->vm_end - vma->vm_start < HPAGE_SIZE)
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return -EINVAL;
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vma_len = (loff_t)(vma->vm_end - vma->vm_start);
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mutex_lock(&inode->i_mutex);
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file_accessed(file);
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vma->vm_flags |= VM_HUGETLB | VM_RESERVED;
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vma->vm_ops = &hugetlb_vm_ops;
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ret = -ENOMEM;
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len = vma_len + ((loff_t)vma->vm_pgoff << PAGE_SHIFT);
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if (vma->vm_flags & VM_MAYSHARE &&
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hugetlb_reserve_pages(inode, vma->vm_pgoff >> (HPAGE_SHIFT-PAGE_SHIFT),
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len >> HPAGE_SHIFT))
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goto out;
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ret = 0;
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hugetlb_prefault_arch_hook(vma->vm_mm);
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if (vma->vm_flags & VM_WRITE && inode->i_size < len)
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inode->i_size = len;
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out:
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mutex_unlock(&inode->i_mutex);
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return ret;
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}
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/*
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* Called under down_write(mmap_sem).
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*/
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#ifdef HAVE_ARCH_HUGETLB_UNMAPPED_AREA
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unsigned long hugetlb_get_unmapped_area(struct file *file, unsigned long addr,
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unsigned long len, unsigned long pgoff, unsigned long flags);
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#else
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static unsigned long
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hugetlb_get_unmapped_area(struct file *file, unsigned long addr,
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unsigned long len, unsigned long pgoff, unsigned long flags)
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{
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struct mm_struct *mm = current->mm;
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struct vm_area_struct *vma;
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unsigned long start_addr;
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if (len & ~HPAGE_MASK)
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return -EINVAL;
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if (len > TASK_SIZE)
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return -ENOMEM;
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if (addr) {
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addr = ALIGN(addr, HPAGE_SIZE);
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vma = find_vma(mm, addr);
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if (TASK_SIZE - len >= addr &&
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(!vma || addr + len <= vma->vm_start))
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return addr;
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}
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start_addr = mm->free_area_cache;
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if (len <= mm->cached_hole_size)
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start_addr = TASK_UNMAPPED_BASE;
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full_search:
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addr = ALIGN(start_addr, HPAGE_SIZE);
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for (vma = find_vma(mm, addr); ; vma = vma->vm_next) {
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/* At this point: (!vma || addr < vma->vm_end). */
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if (TASK_SIZE - len < addr) {
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/*
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* Start a new search - just in case we missed
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* some holes.
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*/
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if (start_addr != TASK_UNMAPPED_BASE) {
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start_addr = TASK_UNMAPPED_BASE;
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goto full_search;
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}
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return -ENOMEM;
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}
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if (!vma || addr + len <= vma->vm_start)
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return addr;
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addr = ALIGN(vma->vm_end, HPAGE_SIZE);
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}
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}
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#endif
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/*
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* Read a page. Again trivial. If it didn't already exist
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* in the page cache, it is zero-filled.
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*/
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static int hugetlbfs_readpage(struct file *file, struct page * page)
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{
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unlock_page(page);
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return -EINVAL;
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}
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static int hugetlbfs_prepare_write(struct file *file,
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struct page *page, unsigned offset, unsigned to)
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{
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return -EINVAL;
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}
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static int hugetlbfs_commit_write(struct file *file,
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struct page *page, unsigned offset, unsigned to)
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{
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return -EINVAL;
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}
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static void truncate_huge_page(struct page *page)
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{
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clear_page_dirty(page);
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ClearPageUptodate(page);
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remove_from_page_cache(page);
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put_page(page);
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}
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static void truncate_hugepages(struct inode *inode, loff_t lstart)
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{
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struct address_space *mapping = &inode->i_data;
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const pgoff_t start = lstart >> HPAGE_SHIFT;
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struct pagevec pvec;
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pgoff_t next;
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int i, freed = 0;
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pagevec_init(&pvec, 0);
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next = start;
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while (1) {
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if (!pagevec_lookup(&pvec, mapping, next, PAGEVEC_SIZE)) {
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if (next == start)
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break;
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next = start;
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continue;
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}
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for (i = 0; i < pagevec_count(&pvec); ++i) {
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struct page *page = pvec.pages[i];
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lock_page(page);
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if (page->index > next)
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next = page->index;
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++next;
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truncate_huge_page(page);
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unlock_page(page);
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hugetlb_put_quota(mapping);
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freed++;
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}
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huge_pagevec_release(&pvec);
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}
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BUG_ON(!lstart && mapping->nrpages);
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hugetlb_unreserve_pages(inode, start, freed);
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}
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static void hugetlbfs_delete_inode(struct inode *inode)
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{
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truncate_hugepages(inode, 0);
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clear_inode(inode);
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}
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static void hugetlbfs_forget_inode(struct inode *inode)
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{
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struct super_block *sb = inode->i_sb;
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if (!hlist_unhashed(&inode->i_hash)) {
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if (!(inode->i_state & (I_DIRTY|I_LOCK)))
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list_move(&inode->i_list, &inode_unused);
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inodes_stat.nr_unused++;
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if (!sb || (sb->s_flags & MS_ACTIVE)) {
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spin_unlock(&inode_lock);
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return;
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}
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inode->i_state |= I_WILL_FREE;
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spin_unlock(&inode_lock);
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/*
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* write_inode_now is a noop as we set BDI_CAP_NO_WRITEBACK
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* in our backing_dev_info.
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*/
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write_inode_now(inode, 1);
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spin_lock(&inode_lock);
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inode->i_state &= ~I_WILL_FREE;
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inodes_stat.nr_unused--;
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hlist_del_init(&inode->i_hash);
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}
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list_del_init(&inode->i_list);
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list_del_init(&inode->i_sb_list);
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inode->i_state |= I_FREEING;
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inodes_stat.nr_inodes--;
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spin_unlock(&inode_lock);
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truncate_hugepages(inode, 0);
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clear_inode(inode);
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destroy_inode(inode);
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}
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static void hugetlbfs_drop_inode(struct inode *inode)
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{
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if (!inode->i_nlink)
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generic_delete_inode(inode);
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else
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hugetlbfs_forget_inode(inode);
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}
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/*
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* h_pgoff is in HPAGE_SIZE units.
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* vma->vm_pgoff is in PAGE_SIZE units.
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*/
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static inline void
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hugetlb_vmtruncate_list(struct prio_tree_root *root, unsigned long h_pgoff)
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{
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struct vm_area_struct *vma;
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struct prio_tree_iter iter;
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vma_prio_tree_foreach(vma, &iter, root, h_pgoff, ULONG_MAX) {
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unsigned long h_vm_pgoff;
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unsigned long v_offset;
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h_vm_pgoff = vma->vm_pgoff >> (HPAGE_SHIFT - PAGE_SHIFT);
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v_offset = (h_pgoff - h_vm_pgoff) << HPAGE_SHIFT;
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/*
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* Is this VMA fully outside the truncation point?
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*/
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if (h_vm_pgoff >= h_pgoff)
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v_offset = 0;
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unmap_hugepage_range(vma,
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vma->vm_start + v_offset, vma->vm_end);
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}
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}
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/*
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* Expanding truncates are not allowed.
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*/
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static int hugetlb_vmtruncate(struct inode *inode, loff_t offset)
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{
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unsigned long pgoff;
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struct address_space *mapping = inode->i_mapping;
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if (offset > inode->i_size)
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return -EINVAL;
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BUG_ON(offset & ~HPAGE_MASK);
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pgoff = offset >> HPAGE_SHIFT;
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inode->i_size = offset;
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spin_lock(&mapping->i_mmap_lock);
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if (!prio_tree_empty(&mapping->i_mmap))
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hugetlb_vmtruncate_list(&mapping->i_mmap, pgoff);
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spin_unlock(&mapping->i_mmap_lock);
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truncate_hugepages(inode, offset);
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return 0;
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}
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static int hugetlbfs_setattr(struct dentry *dentry, struct iattr *attr)
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{
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struct inode *inode = dentry->d_inode;
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int error;
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unsigned int ia_valid = attr->ia_valid;
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BUG_ON(!inode);
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error = inode_change_ok(inode, attr);
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if (error)
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goto out;
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if (ia_valid & ATTR_SIZE) {
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error = -EINVAL;
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if (!(attr->ia_size & ~HPAGE_MASK))
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error = hugetlb_vmtruncate(inode, attr->ia_size);
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if (error)
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goto out;
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attr->ia_valid &= ~ATTR_SIZE;
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}
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error = inode_setattr(inode, attr);
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out:
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return error;
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}
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static struct inode *hugetlbfs_get_inode(struct super_block *sb, uid_t uid,
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gid_t gid, int mode, dev_t dev)
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{
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struct inode *inode;
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inode = new_inode(sb);
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if (inode) {
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struct hugetlbfs_inode_info *info;
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inode->i_mode = mode;
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inode->i_uid = uid;
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inode->i_gid = gid;
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inode->i_blocks = 0;
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inode->i_mapping->a_ops = &hugetlbfs_aops;
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inode->i_mapping->backing_dev_info =&hugetlbfs_backing_dev_info;
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inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
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INIT_LIST_HEAD(&inode->i_mapping->private_list);
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info = HUGETLBFS_I(inode);
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mpol_shared_policy_init(&info->policy, MPOL_DEFAULT, NULL);
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switch (mode & S_IFMT) {
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default:
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init_special_inode(inode, mode, dev);
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break;
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case S_IFREG:
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inode->i_op = &hugetlbfs_inode_operations;
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inode->i_fop = &hugetlbfs_file_operations;
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break;
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case S_IFDIR:
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inode->i_op = &hugetlbfs_dir_inode_operations;
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inode->i_fop = &simple_dir_operations;
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/* directory inodes start off with i_nlink == 2 (for "." entry) */
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inode->i_nlink++;
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break;
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case S_IFLNK:
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inode->i_op = &page_symlink_inode_operations;
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break;
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}
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}
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return inode;
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}
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/*
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* File creation. Allocate an inode, and we're done..
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*/
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static int hugetlbfs_mknod(struct inode *dir,
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struct dentry *dentry, int mode, dev_t dev)
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{
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struct inode *inode;
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int error = -ENOSPC;
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gid_t gid;
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if (dir->i_mode & S_ISGID) {
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gid = dir->i_gid;
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if (S_ISDIR(mode))
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mode |= S_ISGID;
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} else {
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gid = current->fsgid;
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}
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inode = hugetlbfs_get_inode(dir->i_sb, current->fsuid, gid, mode, dev);
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if (inode) {
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dir->i_ctime = dir->i_mtime = CURRENT_TIME;
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d_instantiate(dentry, inode);
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dget(dentry); /* Extra count - pin the dentry in core */
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error = 0;
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}
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return error;
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}
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static int hugetlbfs_mkdir(struct inode *dir, struct dentry *dentry, int mode)
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{
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int retval = hugetlbfs_mknod(dir, dentry, mode | S_IFDIR, 0);
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if (!retval)
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dir->i_nlink++;
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return retval;
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}
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static int hugetlbfs_create(struct inode *dir, struct dentry *dentry, int mode, struct nameidata *nd)
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{
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return hugetlbfs_mknod(dir, dentry, mode | S_IFREG, 0);
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}
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static int hugetlbfs_symlink(struct inode *dir,
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struct dentry *dentry, const char *symname)
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{
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struct inode *inode;
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int error = -ENOSPC;
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gid_t gid;
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if (dir->i_mode & S_ISGID)
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gid = dir->i_gid;
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else
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gid = current->fsgid;
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inode = hugetlbfs_get_inode(dir->i_sb, current->fsuid,
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gid, S_IFLNK|S_IRWXUGO, 0);
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if (inode) {
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int l = strlen(symname)+1;
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error = page_symlink(inode, symname, l);
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if (!error) {
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d_instantiate(dentry, inode);
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dget(dentry);
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} else
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iput(inode);
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}
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dir->i_ctime = dir->i_mtime = CURRENT_TIME;
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return error;
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}
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/*
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* For direct-IO reads into hugetlb pages
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*/
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static int hugetlbfs_set_page_dirty(struct page *page)
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{
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return 0;
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}
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static int hugetlbfs_statfs(struct dentry *dentry, struct kstatfs *buf)
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{
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struct hugetlbfs_sb_info *sbinfo = HUGETLBFS_SB(dentry->d_sb);
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buf->f_type = HUGETLBFS_MAGIC;
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buf->f_bsize = HPAGE_SIZE;
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if (sbinfo) {
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spin_lock(&sbinfo->stat_lock);
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/* If no limits set, just report 0 for max/free/used
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* blocks, like simple_statfs() */
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if (sbinfo->max_blocks >= 0) {
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buf->f_blocks = sbinfo->max_blocks;
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buf->f_bavail = buf->f_bfree = sbinfo->free_blocks;
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buf->f_files = sbinfo->max_inodes;
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buf->f_ffree = sbinfo->free_inodes;
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}
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spin_unlock(&sbinfo->stat_lock);
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}
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buf->f_namelen = NAME_MAX;
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return 0;
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}
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static void hugetlbfs_put_super(struct super_block *sb)
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{
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struct hugetlbfs_sb_info *sbi = HUGETLBFS_SB(sb);
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if (sbi) {
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sb->s_fs_info = NULL;
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kfree(sbi);
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}
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}
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static inline int hugetlbfs_dec_free_inodes(struct hugetlbfs_sb_info *sbinfo)
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{
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if (sbinfo->free_inodes >= 0) {
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spin_lock(&sbinfo->stat_lock);
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if (unlikely(!sbinfo->free_inodes)) {
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spin_unlock(&sbinfo->stat_lock);
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return 0;
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}
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sbinfo->free_inodes--;
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spin_unlock(&sbinfo->stat_lock);
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}
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return 1;
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}
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static void hugetlbfs_inc_free_inodes(struct hugetlbfs_sb_info *sbinfo)
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{
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if (sbinfo->free_inodes >= 0) {
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spin_lock(&sbinfo->stat_lock);
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sbinfo->free_inodes++;
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spin_unlock(&sbinfo->stat_lock);
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}
|
|
}
|
|
|
|
|
|
static kmem_cache_t *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, SLAB_KERNEL);
|
|
if (unlikely(!p)) {
|
|
hugetlbfs_inc_free_inodes(sbinfo);
|
|
return NULL;
|
|
}
|
|
return &p->vfs_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);
|
|
kmem_cache_free(hugetlbfs_inode_cachep, HUGETLBFS_I(inode));
|
|
}
|
|
|
|
static const struct address_space_operations hugetlbfs_aops = {
|
|
.readpage = hugetlbfs_readpage,
|
|
.prepare_write = hugetlbfs_prepare_write,
|
|
.commit_write = hugetlbfs_commit_write,
|
|
.set_page_dirty = hugetlbfs_set_page_dirty,
|
|
};
|
|
|
|
|
|
static void init_once(void *foo, kmem_cache_t *cachep, unsigned long flags)
|
|
{
|
|
struct hugetlbfs_inode_info *ei = (struct hugetlbfs_inode_info *)foo;
|
|
|
|
if ((flags & (SLAB_CTOR_VERIFY|SLAB_CTOR_CONSTRUCTOR)) ==
|
|
SLAB_CTOR_CONSTRUCTOR)
|
|
inode_init_once(&ei->vfs_inode);
|
|
}
|
|
|
|
const struct file_operations hugetlbfs_file_operations = {
|
|
.mmap = hugetlbfs_file_mmap,
|
|
.fsync = simple_sync_file,
|
|
.get_unmapped_area = hugetlb_get_unmapped_area,
|
|
};
|
|
|
|
static 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 struct inode_operations hugetlbfs_inode_operations = {
|
|
.setattr = hugetlbfs_setattr,
|
|
};
|
|
|
|
static struct super_operations hugetlbfs_ops = {
|
|
.alloc_inode = hugetlbfs_alloc_inode,
|
|
.destroy_inode = hugetlbfs_destroy_inode,
|
|
.statfs = hugetlbfs_statfs,
|
|
.delete_inode = hugetlbfs_delete_inode,
|
|
.drop_inode = hugetlbfs_drop_inode,
|
|
.put_super = hugetlbfs_put_super,
|
|
};
|
|
|
|
static int
|
|
hugetlbfs_parse_options(char *options, struct hugetlbfs_config *pconfig)
|
|
{
|
|
char *opt, *value, *rest;
|
|
|
|
if (!options)
|
|
return 0;
|
|
while ((opt = strsep(&options, ",")) != NULL) {
|
|
if (!*opt)
|
|
continue;
|
|
|
|
value = strchr(opt, '=');
|
|
if (!value || !*value)
|
|
return -EINVAL;
|
|
else
|
|
*value++ = '\0';
|
|
|
|
if (!strcmp(opt, "uid"))
|
|
pconfig->uid = simple_strtoul(value, &value, 0);
|
|
else if (!strcmp(opt, "gid"))
|
|
pconfig->gid = simple_strtoul(value, &value, 0);
|
|
else if (!strcmp(opt, "mode"))
|
|
pconfig->mode = simple_strtoul(value,&value,0) & 0777U;
|
|
else if (!strcmp(opt, "size")) {
|
|
unsigned long long size = memparse(value, &rest);
|
|
if (*rest == '%') {
|
|
size <<= HPAGE_SHIFT;
|
|
size *= max_huge_pages;
|
|
do_div(size, 100);
|
|
rest++;
|
|
}
|
|
size &= HPAGE_MASK;
|
|
pconfig->nr_blocks = (size >> HPAGE_SHIFT);
|
|
value = rest;
|
|
} else if (!strcmp(opt,"nr_inodes")) {
|
|
pconfig->nr_inodes = memparse(value, &rest);
|
|
value = rest;
|
|
} else
|
|
return -EINVAL;
|
|
|
|
if (*value)
|
|
return -EINVAL;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
static int
|
|
hugetlbfs_fill_super(struct super_block *sb, void *data, int silent)
|
|
{
|
|
struct inode * inode;
|
|
struct dentry * root;
|
|
int ret;
|
|
struct hugetlbfs_config config;
|
|
struct hugetlbfs_sb_info *sbinfo;
|
|
|
|
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;
|
|
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;
|
|
spin_lock_init(&sbinfo->stat_lock);
|
|
sbinfo->max_blocks = config.nr_blocks;
|
|
sbinfo->free_blocks = config.nr_blocks;
|
|
sbinfo->max_inodes = config.nr_inodes;
|
|
sbinfo->free_inodes = config.nr_inodes;
|
|
sb->s_maxbytes = MAX_LFS_FILESIZE;
|
|
sb->s_blocksize = HPAGE_SIZE;
|
|
sb->s_blocksize_bits = HPAGE_SHIFT;
|
|
sb->s_magic = HUGETLBFS_MAGIC;
|
|
sb->s_op = &hugetlbfs_ops;
|
|
sb->s_time_gran = 1;
|
|
inode = hugetlbfs_get_inode(sb, config.uid, config.gid,
|
|
S_IFDIR | config.mode, 0);
|
|
if (!inode)
|
|
goto out_free;
|
|
|
|
root = d_alloc_root(inode);
|
|
if (!root) {
|
|
iput(inode);
|
|
goto out_free;
|
|
}
|
|
sb->s_root = root;
|
|
return 0;
|
|
out_free:
|
|
kfree(sbinfo);
|
|
return -ENOMEM;
|
|
}
|
|
|
|
int hugetlb_get_quota(struct address_space *mapping)
|
|
{
|
|
int ret = 0;
|
|
struct hugetlbfs_sb_info *sbinfo = HUGETLBFS_SB(mapping->host->i_sb);
|
|
|
|
if (sbinfo->free_blocks > -1) {
|
|
spin_lock(&sbinfo->stat_lock);
|
|
if (sbinfo->free_blocks > 0)
|
|
sbinfo->free_blocks--;
|
|
else
|
|
ret = -ENOMEM;
|
|
spin_unlock(&sbinfo->stat_lock);
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
void hugetlb_put_quota(struct address_space *mapping)
|
|
{
|
|
struct hugetlbfs_sb_info *sbinfo = HUGETLBFS_SB(mapping->host->i_sb);
|
|
|
|
if (sbinfo->free_blocks > -1) {
|
|
spin_lock(&sbinfo->stat_lock);
|
|
sbinfo->free_blocks++;
|
|
spin_unlock(&sbinfo->stat_lock);
|
|
}
|
|
}
|
|
|
|
static int hugetlbfs_get_sb(struct file_system_type *fs_type,
|
|
int flags, const char *dev_name, void *data, struct vfsmount *mnt)
|
|
{
|
|
return get_sb_nodev(fs_type, flags, data, hugetlbfs_fill_super, mnt);
|
|
}
|
|
|
|
static struct file_system_type hugetlbfs_fs_type = {
|
|
.name = "hugetlbfs",
|
|
.get_sb = hugetlbfs_get_sb,
|
|
.kill_sb = kill_litter_super,
|
|
};
|
|
|
|
static struct vfsmount *hugetlbfs_vfsmount;
|
|
|
|
static int can_do_hugetlb_shm(void)
|
|
{
|
|
return likely(capable(CAP_IPC_LOCK) ||
|
|
in_group_p(sysctl_hugetlb_shm_group) ||
|
|
can_do_mlock());
|
|
}
|
|
|
|
struct file *hugetlb_zero_setup(size_t size)
|
|
{
|
|
int error = -ENOMEM;
|
|
struct file *file;
|
|
struct inode *inode;
|
|
struct dentry *dentry, *root;
|
|
struct qstr quick_string;
|
|
char buf[16];
|
|
static atomic_t counter;
|
|
|
|
if (!can_do_hugetlb_shm())
|
|
return ERR_PTR(-EPERM);
|
|
|
|
if (!user_shm_lock(size, current->user))
|
|
return ERR_PTR(-ENOMEM);
|
|
|
|
root = hugetlbfs_vfsmount->mnt_root;
|
|
snprintf(buf, 16, "%u", atomic_inc_return(&counter));
|
|
quick_string.name = buf;
|
|
quick_string.len = strlen(quick_string.name);
|
|
quick_string.hash = 0;
|
|
dentry = d_alloc(root, &quick_string);
|
|
if (!dentry)
|
|
goto out_shm_unlock;
|
|
|
|
error = -ENFILE;
|
|
file = get_empty_filp();
|
|
if (!file)
|
|
goto out_dentry;
|
|
|
|
error = -ENOSPC;
|
|
inode = hugetlbfs_get_inode(root->d_sb, current->fsuid,
|
|
current->fsgid, S_IFREG | S_IRWXUGO, 0);
|
|
if (!inode)
|
|
goto out_file;
|
|
|
|
error = -ENOMEM;
|
|
if (hugetlb_reserve_pages(inode, 0, size >> HPAGE_SHIFT))
|
|
goto out_inode;
|
|
|
|
d_instantiate(dentry, inode);
|
|
inode->i_size = size;
|
|
inode->i_nlink = 0;
|
|
file->f_vfsmnt = mntget(hugetlbfs_vfsmount);
|
|
file->f_dentry = dentry;
|
|
file->f_mapping = inode->i_mapping;
|
|
file->f_op = &hugetlbfs_file_operations;
|
|
file->f_mode = FMODE_WRITE | FMODE_READ;
|
|
return file;
|
|
|
|
out_inode:
|
|
iput(inode);
|
|
out_file:
|
|
put_filp(file);
|
|
out_dentry:
|
|
dput(dentry);
|
|
out_shm_unlock:
|
|
user_shm_unlock(size, current->user);
|
|
return ERR_PTR(error);
|
|
}
|
|
|
|
static int __init init_hugetlbfs_fs(void)
|
|
{
|
|
int error;
|
|
struct vfsmount *vfsmount;
|
|
|
|
hugetlbfs_inode_cachep = kmem_cache_create("hugetlbfs_inode_cache",
|
|
sizeof(struct hugetlbfs_inode_info),
|
|
0, 0, init_once, NULL);
|
|
if (hugetlbfs_inode_cachep == NULL)
|
|
return -ENOMEM;
|
|
|
|
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:
|
|
if (error)
|
|
kmem_cache_destroy(hugetlbfs_inode_cachep);
|
|
return error;
|
|
}
|
|
|
|
static void __exit exit_hugetlbfs_fs(void)
|
|
{
|
|
kmem_cache_destroy(hugetlbfs_inode_cachep);
|
|
unregister_filesystem(&hugetlbfs_fs_type);
|
|
}
|
|
|
|
module_init(init_hugetlbfs_fs)
|
|
module_exit(exit_hugetlbfs_fs)
|
|
|
|
MODULE_LICENSE("GPL");
|