11da177e4SLinus Torvalds /* 21da177e4SLinus Torvalds * hugetlbpage-backed filesystem. Based on ramfs. 31da177e4SLinus Torvalds * 41da177e4SLinus Torvalds * William Irwin, 2002 51da177e4SLinus Torvalds * 61da177e4SLinus Torvalds * Copyright (C) 2002 Linus Torvalds. 71da177e4SLinus Torvalds */ 81da177e4SLinus Torvalds 91da177e4SLinus Torvalds #include <linux/module.h> 101da177e4SLinus Torvalds #include <linux/thread_info.h> 111da177e4SLinus Torvalds #include <asm/current.h> 121da177e4SLinus Torvalds #include <linux/sched.h> /* remove ASAP */ 131da177e4SLinus Torvalds #include <linux/fs.h> 141da177e4SLinus Torvalds #include <linux/mount.h> 151da177e4SLinus Torvalds #include <linux/file.h> 161da177e4SLinus Torvalds #include <linux/writeback.h> 171da177e4SLinus Torvalds #include <linux/pagemap.h> 181da177e4SLinus Torvalds #include <linux/highmem.h> 191da177e4SLinus Torvalds #include <linux/init.h> 201da177e4SLinus Torvalds #include <linux/string.h> 211da177e4SLinus Torvalds #include <linux/backing-dev.h> 221da177e4SLinus Torvalds #include <linux/hugetlb.h> 231da177e4SLinus Torvalds #include <linux/pagevec.h> 241da177e4SLinus Torvalds #include <linux/quotaops.h> 251da177e4SLinus Torvalds #include <linux/slab.h> 261da177e4SLinus Torvalds #include <linux/dnotify.h> 271da177e4SLinus Torvalds #include <linux/statfs.h> 281da177e4SLinus Torvalds #include <linux/security.h> 291da177e4SLinus Torvalds 301da177e4SLinus Torvalds #include <asm/uaccess.h> 311da177e4SLinus Torvalds 321da177e4SLinus Torvalds /* some random number */ 331da177e4SLinus Torvalds #define HUGETLBFS_MAGIC 0x958458f6 341da177e4SLinus Torvalds 351da177e4SLinus Torvalds static struct super_operations hugetlbfs_ops; 361da177e4SLinus Torvalds static struct address_space_operations hugetlbfs_aops; 371da177e4SLinus Torvalds struct file_operations hugetlbfs_file_operations; 381da177e4SLinus Torvalds static struct inode_operations hugetlbfs_dir_inode_operations; 391da177e4SLinus Torvalds static struct inode_operations hugetlbfs_inode_operations; 401da177e4SLinus Torvalds 411da177e4SLinus Torvalds static struct backing_dev_info hugetlbfs_backing_dev_info = { 421da177e4SLinus Torvalds .ra_pages = 0, /* No readahead */ 431da177e4SLinus Torvalds .capabilities = BDI_CAP_NO_ACCT_DIRTY | BDI_CAP_NO_WRITEBACK, 441da177e4SLinus Torvalds }; 451da177e4SLinus Torvalds 461da177e4SLinus Torvalds int sysctl_hugetlb_shm_group; 471da177e4SLinus Torvalds 481da177e4SLinus Torvalds static int hugetlbfs_file_mmap(struct file *file, struct vm_area_struct *vma) 491da177e4SLinus Torvalds { 501da177e4SLinus Torvalds struct inode *inode = file->f_dentry->d_inode; 511da177e4SLinus Torvalds loff_t len, vma_len; 521da177e4SLinus Torvalds int ret; 531da177e4SLinus Torvalds 541da177e4SLinus Torvalds if ((vma->vm_flags & (VM_MAYSHARE | VM_WRITE)) == VM_WRITE) 551da177e4SLinus Torvalds return -EINVAL; 561da177e4SLinus Torvalds 571da177e4SLinus Torvalds if (vma->vm_pgoff & (HPAGE_SIZE / PAGE_SIZE - 1)) 581da177e4SLinus Torvalds return -EINVAL; 591da177e4SLinus Torvalds 601da177e4SLinus Torvalds if (vma->vm_start & ~HPAGE_MASK) 611da177e4SLinus Torvalds return -EINVAL; 621da177e4SLinus Torvalds 631da177e4SLinus Torvalds if (vma->vm_end & ~HPAGE_MASK) 641da177e4SLinus Torvalds return -EINVAL; 651da177e4SLinus Torvalds 661da177e4SLinus Torvalds if (vma->vm_end - vma->vm_start < HPAGE_SIZE) 671da177e4SLinus Torvalds return -EINVAL; 681da177e4SLinus Torvalds 691da177e4SLinus Torvalds vma_len = (loff_t)(vma->vm_end - vma->vm_start); 701da177e4SLinus Torvalds 711da177e4SLinus Torvalds down(&inode->i_sem); 721da177e4SLinus Torvalds file_accessed(file); 731da177e4SLinus Torvalds vma->vm_flags |= VM_HUGETLB | VM_RESERVED; 741da177e4SLinus Torvalds vma->vm_ops = &hugetlb_vm_ops; 751da177e4SLinus Torvalds 761da177e4SLinus Torvalds ret = -ENOMEM; 771da177e4SLinus Torvalds len = vma_len + ((loff_t)vma->vm_pgoff << PAGE_SHIFT); 781da177e4SLinus Torvalds if (!(vma->vm_flags & VM_WRITE) && len > inode->i_size) 791da177e4SLinus Torvalds goto out; 801da177e4SLinus Torvalds 814c887265SAdam Litke ret = 0; 824c887265SAdam Litke hugetlb_prefault_arch_hook(vma->vm_mm); 831da177e4SLinus Torvalds if (inode->i_size < len) 841da177e4SLinus Torvalds inode->i_size = len; 851da177e4SLinus Torvalds out: 861da177e4SLinus Torvalds up(&inode->i_sem); 871da177e4SLinus Torvalds 881da177e4SLinus Torvalds return ret; 891da177e4SLinus Torvalds } 901da177e4SLinus Torvalds 911da177e4SLinus Torvalds /* 92508034a3SHugh Dickins * Called under down_write(mmap_sem). 931da177e4SLinus Torvalds */ 941da177e4SLinus Torvalds 951da177e4SLinus Torvalds #ifdef HAVE_ARCH_HUGETLB_UNMAPPED_AREA 961da177e4SLinus Torvalds unsigned long hugetlb_get_unmapped_area(struct file *file, unsigned long addr, 971da177e4SLinus Torvalds unsigned long len, unsigned long pgoff, unsigned long flags); 981da177e4SLinus Torvalds #else 991da177e4SLinus Torvalds static unsigned long 1001da177e4SLinus Torvalds hugetlb_get_unmapped_area(struct file *file, unsigned long addr, 1011da177e4SLinus Torvalds unsigned long len, unsigned long pgoff, unsigned long flags) 1021da177e4SLinus Torvalds { 1031da177e4SLinus Torvalds struct mm_struct *mm = current->mm; 1041da177e4SLinus Torvalds struct vm_area_struct *vma; 1051da177e4SLinus Torvalds unsigned long start_addr; 1061da177e4SLinus Torvalds 1071da177e4SLinus Torvalds if (len & ~HPAGE_MASK) 1081da177e4SLinus Torvalds return -EINVAL; 1091da177e4SLinus Torvalds if (len > TASK_SIZE) 1101da177e4SLinus Torvalds return -ENOMEM; 1111da177e4SLinus Torvalds 1121da177e4SLinus Torvalds if (addr) { 1131da177e4SLinus Torvalds addr = ALIGN(addr, HPAGE_SIZE); 1141da177e4SLinus Torvalds vma = find_vma(mm, addr); 1151da177e4SLinus Torvalds if (TASK_SIZE - len >= addr && 1161da177e4SLinus Torvalds (!vma || addr + len <= vma->vm_start)) 1171da177e4SLinus Torvalds return addr; 1181da177e4SLinus Torvalds } 1191da177e4SLinus Torvalds 1201da177e4SLinus Torvalds start_addr = mm->free_area_cache; 1211da177e4SLinus Torvalds 1221363c3cdSWolfgang Wander if (len <= mm->cached_hole_size) 1231363c3cdSWolfgang Wander start_addr = TASK_UNMAPPED_BASE; 1241363c3cdSWolfgang Wander 1251da177e4SLinus Torvalds full_search: 1261da177e4SLinus Torvalds addr = ALIGN(start_addr, HPAGE_SIZE); 1271da177e4SLinus Torvalds 1281da177e4SLinus Torvalds for (vma = find_vma(mm, addr); ; vma = vma->vm_next) { 1291da177e4SLinus Torvalds /* At this point: (!vma || addr < vma->vm_end). */ 1301da177e4SLinus Torvalds if (TASK_SIZE - len < addr) { 1311da177e4SLinus Torvalds /* 1321da177e4SLinus Torvalds * Start a new search - just in case we missed 1331da177e4SLinus Torvalds * some holes. 1341da177e4SLinus Torvalds */ 1351da177e4SLinus Torvalds if (start_addr != TASK_UNMAPPED_BASE) { 1361da177e4SLinus Torvalds start_addr = TASK_UNMAPPED_BASE; 1371da177e4SLinus Torvalds goto full_search; 1381da177e4SLinus Torvalds } 1391da177e4SLinus Torvalds return -ENOMEM; 1401da177e4SLinus Torvalds } 1411da177e4SLinus Torvalds 1421da177e4SLinus Torvalds if (!vma || addr + len <= vma->vm_start) 1431da177e4SLinus Torvalds return addr; 1441da177e4SLinus Torvalds addr = ALIGN(vma->vm_end, HPAGE_SIZE); 1451da177e4SLinus Torvalds } 1461da177e4SLinus Torvalds } 1471da177e4SLinus Torvalds #endif 1481da177e4SLinus Torvalds 1491da177e4SLinus Torvalds /* 1501da177e4SLinus Torvalds * Read a page. Again trivial. If it didn't already exist 1511da177e4SLinus Torvalds * in the page cache, it is zero-filled. 1521da177e4SLinus Torvalds */ 1531da177e4SLinus Torvalds static int hugetlbfs_readpage(struct file *file, struct page * page) 1541da177e4SLinus Torvalds { 1551da177e4SLinus Torvalds unlock_page(page); 1561da177e4SLinus Torvalds return -EINVAL; 1571da177e4SLinus Torvalds } 1581da177e4SLinus Torvalds 1591da177e4SLinus Torvalds static int hugetlbfs_prepare_write(struct file *file, 1601da177e4SLinus Torvalds struct page *page, unsigned offset, unsigned to) 1611da177e4SLinus Torvalds { 1621da177e4SLinus Torvalds return -EINVAL; 1631da177e4SLinus Torvalds } 1641da177e4SLinus Torvalds 1651da177e4SLinus Torvalds static int hugetlbfs_commit_write(struct file *file, 1661da177e4SLinus Torvalds struct page *page, unsigned offset, unsigned to) 1671da177e4SLinus Torvalds { 1681da177e4SLinus Torvalds return -EINVAL; 1691da177e4SLinus Torvalds } 1701da177e4SLinus Torvalds 1711da177e4SLinus Torvalds static void huge_pagevec_release(struct pagevec *pvec) 1721da177e4SLinus Torvalds { 1731da177e4SLinus Torvalds int i; 1741da177e4SLinus Torvalds 1751da177e4SLinus Torvalds for (i = 0; i < pagevec_count(pvec); ++i) 1761da177e4SLinus Torvalds put_page(pvec->pages[i]); 1771da177e4SLinus Torvalds 1781da177e4SLinus Torvalds pagevec_reinit(pvec); 1791da177e4SLinus Torvalds } 1801da177e4SLinus Torvalds 1811da177e4SLinus Torvalds static void truncate_huge_page(struct page *page) 1821da177e4SLinus Torvalds { 1831da177e4SLinus Torvalds clear_page_dirty(page); 1841da177e4SLinus Torvalds ClearPageUptodate(page); 1851da177e4SLinus Torvalds remove_from_page_cache(page); 1861da177e4SLinus Torvalds put_page(page); 1871da177e4SLinus Torvalds } 1881da177e4SLinus Torvalds 1891da177e4SLinus Torvalds static void truncate_hugepages(struct address_space *mapping, loff_t lstart) 1901da177e4SLinus Torvalds { 1911da177e4SLinus Torvalds const pgoff_t start = lstart >> HPAGE_SHIFT; 1921da177e4SLinus Torvalds struct pagevec pvec; 1931da177e4SLinus Torvalds pgoff_t next; 1941da177e4SLinus Torvalds int i; 1951da177e4SLinus Torvalds 1961da177e4SLinus Torvalds pagevec_init(&pvec, 0); 1971da177e4SLinus Torvalds next = start; 1981da177e4SLinus Torvalds while (1) { 1991da177e4SLinus Torvalds if (!pagevec_lookup(&pvec, mapping, next, PAGEVEC_SIZE)) { 2001da177e4SLinus Torvalds if (next == start) 2011da177e4SLinus Torvalds break; 2021da177e4SLinus Torvalds next = start; 2031da177e4SLinus Torvalds continue; 2041da177e4SLinus Torvalds } 2051da177e4SLinus Torvalds 2061da177e4SLinus Torvalds for (i = 0; i < pagevec_count(&pvec); ++i) { 2071da177e4SLinus Torvalds struct page *page = pvec.pages[i]; 2081da177e4SLinus Torvalds 2091da177e4SLinus Torvalds lock_page(page); 2101da177e4SLinus Torvalds if (page->index > next) 2111da177e4SLinus Torvalds next = page->index; 2121da177e4SLinus Torvalds ++next; 2131da177e4SLinus Torvalds truncate_huge_page(page); 2141da177e4SLinus Torvalds unlock_page(page); 2151da177e4SLinus Torvalds hugetlb_put_quota(mapping); 2161da177e4SLinus Torvalds } 2171da177e4SLinus Torvalds huge_pagevec_release(&pvec); 2181da177e4SLinus Torvalds } 2191da177e4SLinus Torvalds BUG_ON(!lstart && mapping->nrpages); 2201da177e4SLinus Torvalds } 2211da177e4SLinus Torvalds 2221da177e4SLinus Torvalds static void hugetlbfs_delete_inode(struct inode *inode) 2231da177e4SLinus Torvalds { 224149f4211SChristoph Hellwig if (inode->i_data.nrpages) 225149f4211SChristoph Hellwig truncate_hugepages(&inode->i_data, 0); 226149f4211SChristoph Hellwig clear_inode(inode); 227149f4211SChristoph Hellwig } 228149f4211SChristoph Hellwig 2291da177e4SLinus Torvalds static void hugetlbfs_forget_inode(struct inode *inode) 2301da177e4SLinus Torvalds { 2310b1533f6SChristoph Hellwig struct super_block *sb = inode->i_sb; 2321da177e4SLinus Torvalds 2330b1533f6SChristoph Hellwig if (!hlist_unhashed(&inode->i_hash)) { 2340b1533f6SChristoph Hellwig if (!(inode->i_state & (I_DIRTY|I_LOCK))) 2350b1533f6SChristoph Hellwig list_move(&inode->i_list, &inode_unused); 2361da177e4SLinus Torvalds inodes_stat.nr_unused++; 2370b1533f6SChristoph Hellwig if (!sb || (sb->s_flags & MS_ACTIVE)) { 2381da177e4SLinus Torvalds spin_unlock(&inode_lock); 2391da177e4SLinus Torvalds return; 2401da177e4SLinus Torvalds } 2410b1533f6SChristoph Hellwig inode->i_state |= I_WILL_FREE; 2420b1533f6SChristoph Hellwig spin_unlock(&inode_lock); 2430b1533f6SChristoph Hellwig /* 2440b1533f6SChristoph Hellwig * write_inode_now is a noop as we set BDI_CAP_NO_WRITEBACK 2450b1533f6SChristoph Hellwig * in our backing_dev_info. 2460b1533f6SChristoph Hellwig */ 2470b1533f6SChristoph Hellwig write_inode_now(inode, 1); 2480b1533f6SChristoph Hellwig spin_lock(&inode_lock); 2490b1533f6SChristoph Hellwig inode->i_state &= ~I_WILL_FREE; 2501da177e4SLinus Torvalds inodes_stat.nr_unused--; 2511da177e4SLinus Torvalds hlist_del_init(&inode->i_hash); 2520b1533f6SChristoph Hellwig } 2531da177e4SLinus Torvalds list_del_init(&inode->i_list); 2541da177e4SLinus Torvalds list_del_init(&inode->i_sb_list); 2551da177e4SLinus Torvalds inode->i_state |= I_FREEING; 2561da177e4SLinus Torvalds inodes_stat.nr_inodes--; 2571da177e4SLinus Torvalds spin_unlock(&inode_lock); 2581da177e4SLinus Torvalds if (inode->i_data.nrpages) 2591da177e4SLinus Torvalds truncate_hugepages(&inode->i_data, 0); 2601da177e4SLinus Torvalds clear_inode(inode); 2611da177e4SLinus Torvalds destroy_inode(inode); 2621da177e4SLinus Torvalds } 2631da177e4SLinus Torvalds 2641da177e4SLinus Torvalds static void hugetlbfs_drop_inode(struct inode *inode) 2651da177e4SLinus Torvalds { 2661da177e4SLinus Torvalds if (!inode->i_nlink) 2676b09b9dfSChristoph Hellwig generic_delete_inode(inode); 2681da177e4SLinus Torvalds else 2691da177e4SLinus Torvalds hugetlbfs_forget_inode(inode); 2701da177e4SLinus Torvalds } 2711da177e4SLinus Torvalds 2721da177e4SLinus Torvalds /* 2731da177e4SLinus Torvalds * h_pgoff is in HPAGE_SIZE units. 2741da177e4SLinus Torvalds * vma->vm_pgoff is in PAGE_SIZE units. 2751da177e4SLinus Torvalds */ 2761da177e4SLinus Torvalds static inline void 2771da177e4SLinus Torvalds hugetlb_vmtruncate_list(struct prio_tree_root *root, unsigned long h_pgoff) 2781da177e4SLinus Torvalds { 2791da177e4SLinus Torvalds struct vm_area_struct *vma; 2801da177e4SLinus Torvalds struct prio_tree_iter iter; 2811da177e4SLinus Torvalds 2821da177e4SLinus Torvalds vma_prio_tree_foreach(vma, &iter, root, h_pgoff, ULONG_MAX) { 2831da177e4SLinus Torvalds unsigned long h_vm_pgoff; 2841da177e4SLinus Torvalds unsigned long v_offset; 2851da177e4SLinus Torvalds 2861da177e4SLinus Torvalds h_vm_pgoff = vma->vm_pgoff >> (HPAGE_SHIFT - PAGE_SHIFT); 2871da177e4SLinus Torvalds v_offset = (h_pgoff - h_vm_pgoff) << HPAGE_SHIFT; 2881da177e4SLinus Torvalds /* 2891da177e4SLinus Torvalds * Is this VMA fully outside the truncation point? 2901da177e4SLinus Torvalds */ 2911da177e4SLinus Torvalds if (h_vm_pgoff >= h_pgoff) 2921da177e4SLinus Torvalds v_offset = 0; 2931da177e4SLinus Torvalds 294508034a3SHugh Dickins unmap_hugepage_range(vma, 295508034a3SHugh Dickins vma->vm_start + v_offset, vma->vm_end); 2961da177e4SLinus Torvalds } 2971da177e4SLinus Torvalds } 2981da177e4SLinus Torvalds 2991da177e4SLinus Torvalds /* 3001da177e4SLinus Torvalds * Expanding truncates are not allowed. 3011da177e4SLinus Torvalds */ 3021da177e4SLinus Torvalds static int hugetlb_vmtruncate(struct inode *inode, loff_t offset) 3031da177e4SLinus Torvalds { 3041da177e4SLinus Torvalds unsigned long pgoff; 3051da177e4SLinus Torvalds struct address_space *mapping = inode->i_mapping; 3061da177e4SLinus Torvalds 3071da177e4SLinus Torvalds if (offset > inode->i_size) 3081da177e4SLinus Torvalds return -EINVAL; 3091da177e4SLinus Torvalds 3101da177e4SLinus Torvalds BUG_ON(offset & ~HPAGE_MASK); 3111da177e4SLinus Torvalds pgoff = offset >> HPAGE_SHIFT; 3121da177e4SLinus Torvalds 3131da177e4SLinus Torvalds inode->i_size = offset; 3141da177e4SLinus Torvalds spin_lock(&mapping->i_mmap_lock); 3151da177e4SLinus Torvalds if (!prio_tree_empty(&mapping->i_mmap)) 3161da177e4SLinus Torvalds hugetlb_vmtruncate_list(&mapping->i_mmap, pgoff); 3171da177e4SLinus Torvalds spin_unlock(&mapping->i_mmap_lock); 3181da177e4SLinus Torvalds truncate_hugepages(mapping, offset); 3191da177e4SLinus Torvalds return 0; 3201da177e4SLinus Torvalds } 3211da177e4SLinus Torvalds 3221da177e4SLinus Torvalds static int hugetlbfs_setattr(struct dentry *dentry, struct iattr *attr) 3231da177e4SLinus Torvalds { 3241da177e4SLinus Torvalds struct inode *inode = dentry->d_inode; 3251da177e4SLinus Torvalds int error; 3261da177e4SLinus Torvalds unsigned int ia_valid = attr->ia_valid; 3271da177e4SLinus Torvalds 3281da177e4SLinus Torvalds BUG_ON(!inode); 3291da177e4SLinus Torvalds 3301da177e4SLinus Torvalds error = inode_change_ok(inode, attr); 3311da177e4SLinus Torvalds if (error) 3321da177e4SLinus Torvalds goto out; 3331da177e4SLinus Torvalds 3341da177e4SLinus Torvalds if (ia_valid & ATTR_SIZE) { 3351da177e4SLinus Torvalds error = -EINVAL; 3361da177e4SLinus Torvalds if (!(attr->ia_size & ~HPAGE_MASK)) 3371da177e4SLinus Torvalds error = hugetlb_vmtruncate(inode, attr->ia_size); 3381da177e4SLinus Torvalds if (error) 3391da177e4SLinus Torvalds goto out; 3401da177e4SLinus Torvalds attr->ia_valid &= ~ATTR_SIZE; 3411da177e4SLinus Torvalds } 3421da177e4SLinus Torvalds error = inode_setattr(inode, attr); 3431da177e4SLinus Torvalds out: 3441da177e4SLinus Torvalds return error; 3451da177e4SLinus Torvalds } 3461da177e4SLinus Torvalds 3471da177e4SLinus Torvalds static struct inode *hugetlbfs_get_inode(struct super_block *sb, uid_t uid, 3481da177e4SLinus Torvalds gid_t gid, int mode, dev_t dev) 3491da177e4SLinus Torvalds { 3501da177e4SLinus Torvalds struct inode *inode; 3511da177e4SLinus Torvalds 3521da177e4SLinus Torvalds inode = new_inode(sb); 3531da177e4SLinus Torvalds if (inode) { 3541da177e4SLinus Torvalds struct hugetlbfs_inode_info *info; 3551da177e4SLinus Torvalds inode->i_mode = mode; 3561da177e4SLinus Torvalds inode->i_uid = uid; 3571da177e4SLinus Torvalds inode->i_gid = gid; 3581da177e4SLinus Torvalds inode->i_blksize = HPAGE_SIZE; 3591da177e4SLinus Torvalds inode->i_blocks = 0; 3601da177e4SLinus Torvalds inode->i_mapping->a_ops = &hugetlbfs_aops; 3611da177e4SLinus Torvalds inode->i_mapping->backing_dev_info =&hugetlbfs_backing_dev_info; 3621da177e4SLinus Torvalds inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME; 3631da177e4SLinus Torvalds info = HUGETLBFS_I(inode); 3641da177e4SLinus Torvalds mpol_shared_policy_init(&info->policy); 3651da177e4SLinus Torvalds switch (mode & S_IFMT) { 3661da177e4SLinus Torvalds default: 3671da177e4SLinus Torvalds init_special_inode(inode, mode, dev); 3681da177e4SLinus Torvalds break; 3691da177e4SLinus Torvalds case S_IFREG: 3701da177e4SLinus Torvalds inode->i_op = &hugetlbfs_inode_operations; 3711da177e4SLinus Torvalds inode->i_fop = &hugetlbfs_file_operations; 3721da177e4SLinus Torvalds break; 3731da177e4SLinus Torvalds case S_IFDIR: 3741da177e4SLinus Torvalds inode->i_op = &hugetlbfs_dir_inode_operations; 3751da177e4SLinus Torvalds inode->i_fop = &simple_dir_operations; 3761da177e4SLinus Torvalds 3771da177e4SLinus Torvalds /* directory inodes start off with i_nlink == 2 (for "." entry) */ 3781da177e4SLinus Torvalds inode->i_nlink++; 3791da177e4SLinus Torvalds break; 3801da177e4SLinus Torvalds case S_IFLNK: 3811da177e4SLinus Torvalds inode->i_op = &page_symlink_inode_operations; 3821da177e4SLinus Torvalds break; 3831da177e4SLinus Torvalds } 3841da177e4SLinus Torvalds } 3851da177e4SLinus Torvalds return inode; 3861da177e4SLinus Torvalds } 3871da177e4SLinus Torvalds 3881da177e4SLinus Torvalds /* 3891da177e4SLinus Torvalds * File creation. Allocate an inode, and we're done.. 3901da177e4SLinus Torvalds */ 3911da177e4SLinus Torvalds static int hugetlbfs_mknod(struct inode *dir, 3921da177e4SLinus Torvalds struct dentry *dentry, int mode, dev_t dev) 3931da177e4SLinus Torvalds { 3941da177e4SLinus Torvalds struct inode *inode; 3951da177e4SLinus Torvalds int error = -ENOSPC; 3961da177e4SLinus Torvalds gid_t gid; 3971da177e4SLinus Torvalds 3981da177e4SLinus Torvalds if (dir->i_mode & S_ISGID) { 3991da177e4SLinus Torvalds gid = dir->i_gid; 4001da177e4SLinus Torvalds if (S_ISDIR(mode)) 4011da177e4SLinus Torvalds mode |= S_ISGID; 4021da177e4SLinus Torvalds } else { 4031da177e4SLinus Torvalds gid = current->fsgid; 4041da177e4SLinus Torvalds } 4051da177e4SLinus Torvalds inode = hugetlbfs_get_inode(dir->i_sb, current->fsuid, gid, mode, dev); 4061da177e4SLinus Torvalds if (inode) { 4071da177e4SLinus Torvalds dir->i_ctime = dir->i_mtime = CURRENT_TIME; 4081da177e4SLinus Torvalds d_instantiate(dentry, inode); 4091da177e4SLinus Torvalds dget(dentry); /* Extra count - pin the dentry in core */ 4101da177e4SLinus Torvalds error = 0; 4111da177e4SLinus Torvalds } 4121da177e4SLinus Torvalds return error; 4131da177e4SLinus Torvalds } 4141da177e4SLinus Torvalds 4151da177e4SLinus Torvalds static int hugetlbfs_mkdir(struct inode *dir, struct dentry *dentry, int mode) 4161da177e4SLinus Torvalds { 4171da177e4SLinus Torvalds int retval = hugetlbfs_mknod(dir, dentry, mode | S_IFDIR, 0); 4181da177e4SLinus Torvalds if (!retval) 4191da177e4SLinus Torvalds dir->i_nlink++; 4201da177e4SLinus Torvalds return retval; 4211da177e4SLinus Torvalds } 4221da177e4SLinus Torvalds 4231da177e4SLinus Torvalds static int hugetlbfs_create(struct inode *dir, struct dentry *dentry, int mode, struct nameidata *nd) 4241da177e4SLinus Torvalds { 4251da177e4SLinus Torvalds return hugetlbfs_mknod(dir, dentry, mode | S_IFREG, 0); 4261da177e4SLinus Torvalds } 4271da177e4SLinus Torvalds 4281da177e4SLinus Torvalds static int hugetlbfs_symlink(struct inode *dir, 4291da177e4SLinus Torvalds struct dentry *dentry, const char *symname) 4301da177e4SLinus Torvalds { 4311da177e4SLinus Torvalds struct inode *inode; 4321da177e4SLinus Torvalds int error = -ENOSPC; 4331da177e4SLinus Torvalds gid_t gid; 4341da177e4SLinus Torvalds 4351da177e4SLinus Torvalds if (dir->i_mode & S_ISGID) 4361da177e4SLinus Torvalds gid = dir->i_gid; 4371da177e4SLinus Torvalds else 4381da177e4SLinus Torvalds gid = current->fsgid; 4391da177e4SLinus Torvalds 4401da177e4SLinus Torvalds inode = hugetlbfs_get_inode(dir->i_sb, current->fsuid, 4411da177e4SLinus Torvalds gid, S_IFLNK|S_IRWXUGO, 0); 4421da177e4SLinus Torvalds if (inode) { 4431da177e4SLinus Torvalds int l = strlen(symname)+1; 4441da177e4SLinus Torvalds error = page_symlink(inode, symname, l); 4451da177e4SLinus Torvalds if (!error) { 4461da177e4SLinus Torvalds d_instantiate(dentry, inode); 4471da177e4SLinus Torvalds dget(dentry); 4481da177e4SLinus Torvalds } else 4491da177e4SLinus Torvalds iput(inode); 4501da177e4SLinus Torvalds } 4511da177e4SLinus Torvalds dir->i_ctime = dir->i_mtime = CURRENT_TIME; 4521da177e4SLinus Torvalds 4531da177e4SLinus Torvalds return error; 4541da177e4SLinus Torvalds } 4551da177e4SLinus Torvalds 4561da177e4SLinus Torvalds /* 4571da177e4SLinus Torvalds * For direct-IO reads into hugetlb pages 4581da177e4SLinus Torvalds */ 4591da177e4SLinus Torvalds static int hugetlbfs_set_page_dirty(struct page *page) 4601da177e4SLinus Torvalds { 4611da177e4SLinus Torvalds return 0; 4621da177e4SLinus Torvalds } 4631da177e4SLinus Torvalds 4641da177e4SLinus Torvalds static int hugetlbfs_statfs(struct super_block *sb, struct kstatfs *buf) 4651da177e4SLinus Torvalds { 4661da177e4SLinus Torvalds struct hugetlbfs_sb_info *sbinfo = HUGETLBFS_SB(sb); 4671da177e4SLinus Torvalds 4681da177e4SLinus Torvalds buf->f_type = HUGETLBFS_MAGIC; 4691da177e4SLinus Torvalds buf->f_bsize = HPAGE_SIZE; 4701da177e4SLinus Torvalds if (sbinfo) { 4711da177e4SLinus Torvalds spin_lock(&sbinfo->stat_lock); 4721da177e4SLinus Torvalds buf->f_blocks = sbinfo->max_blocks; 4731da177e4SLinus Torvalds buf->f_bavail = buf->f_bfree = sbinfo->free_blocks; 4741da177e4SLinus Torvalds buf->f_files = sbinfo->max_inodes; 4751da177e4SLinus Torvalds buf->f_ffree = sbinfo->free_inodes; 4761da177e4SLinus Torvalds spin_unlock(&sbinfo->stat_lock); 4771da177e4SLinus Torvalds } 4781da177e4SLinus Torvalds buf->f_namelen = NAME_MAX; 4791da177e4SLinus Torvalds return 0; 4801da177e4SLinus Torvalds } 4811da177e4SLinus Torvalds 4821da177e4SLinus Torvalds static void hugetlbfs_put_super(struct super_block *sb) 4831da177e4SLinus Torvalds { 4841da177e4SLinus Torvalds struct hugetlbfs_sb_info *sbi = HUGETLBFS_SB(sb); 4851da177e4SLinus Torvalds 4861da177e4SLinus Torvalds if (sbi) { 4871da177e4SLinus Torvalds sb->s_fs_info = NULL; 4881da177e4SLinus Torvalds kfree(sbi); 4891da177e4SLinus Torvalds } 4901da177e4SLinus Torvalds } 4911da177e4SLinus Torvalds 49296527980SChristoph Hellwig static inline int hugetlbfs_dec_free_inodes(struct hugetlbfs_sb_info *sbinfo) 49396527980SChristoph Hellwig { 49496527980SChristoph Hellwig if (sbinfo->free_inodes >= 0) { 49596527980SChristoph Hellwig spin_lock(&sbinfo->stat_lock); 49696527980SChristoph Hellwig if (unlikely(!sbinfo->free_inodes)) { 49796527980SChristoph Hellwig spin_unlock(&sbinfo->stat_lock); 49896527980SChristoph Hellwig return 0; 49996527980SChristoph Hellwig } 50096527980SChristoph Hellwig sbinfo->free_inodes--; 50196527980SChristoph Hellwig spin_unlock(&sbinfo->stat_lock); 50296527980SChristoph Hellwig } 50396527980SChristoph Hellwig 50496527980SChristoph Hellwig return 1; 50596527980SChristoph Hellwig } 50696527980SChristoph Hellwig 50796527980SChristoph Hellwig static void hugetlbfs_inc_free_inodes(struct hugetlbfs_sb_info *sbinfo) 50896527980SChristoph Hellwig { 50996527980SChristoph Hellwig if (sbinfo->free_inodes >= 0) { 51096527980SChristoph Hellwig spin_lock(&sbinfo->stat_lock); 51196527980SChristoph Hellwig sbinfo->free_inodes++; 51296527980SChristoph Hellwig spin_unlock(&sbinfo->stat_lock); 51396527980SChristoph Hellwig } 51496527980SChristoph Hellwig } 51596527980SChristoph Hellwig 51696527980SChristoph Hellwig 5171da177e4SLinus Torvalds static kmem_cache_t *hugetlbfs_inode_cachep; 5181da177e4SLinus Torvalds 5191da177e4SLinus Torvalds static struct inode *hugetlbfs_alloc_inode(struct super_block *sb) 5201da177e4SLinus Torvalds { 52196527980SChristoph Hellwig struct hugetlbfs_sb_info *sbinfo = HUGETLBFS_SB(sb); 5221da177e4SLinus Torvalds struct hugetlbfs_inode_info *p; 5231da177e4SLinus Torvalds 52496527980SChristoph Hellwig if (unlikely(!hugetlbfs_dec_free_inodes(sbinfo))) 5251da177e4SLinus Torvalds return NULL; 52696527980SChristoph Hellwig p = kmem_cache_alloc(hugetlbfs_inode_cachep, SLAB_KERNEL); 52796527980SChristoph Hellwig if (unlikely(!p)) { 52896527980SChristoph Hellwig hugetlbfs_inc_free_inodes(sbinfo); 52996527980SChristoph Hellwig return NULL; 5301da177e4SLinus Torvalds } 53196527980SChristoph Hellwig return &p->vfs_inode; 5321da177e4SLinus Torvalds } 5331da177e4SLinus Torvalds 5341da177e4SLinus Torvalds static void hugetlbfs_destroy_inode(struct inode *inode) 5351da177e4SLinus Torvalds { 53696527980SChristoph Hellwig hugetlbfs_inc_free_inodes(HUGETLBFS_SB(inode->i_sb)); 5371da177e4SLinus Torvalds mpol_free_shared_policy(&HUGETLBFS_I(inode)->policy); 5381da177e4SLinus Torvalds kmem_cache_free(hugetlbfs_inode_cachep, HUGETLBFS_I(inode)); 5391da177e4SLinus Torvalds } 5401da177e4SLinus Torvalds 5411da177e4SLinus Torvalds static struct address_space_operations hugetlbfs_aops = { 5421da177e4SLinus Torvalds .readpage = hugetlbfs_readpage, 5431da177e4SLinus Torvalds .prepare_write = hugetlbfs_prepare_write, 5441da177e4SLinus Torvalds .commit_write = hugetlbfs_commit_write, 5451da177e4SLinus Torvalds .set_page_dirty = hugetlbfs_set_page_dirty, 5461da177e4SLinus Torvalds }; 5471da177e4SLinus Torvalds 54896527980SChristoph Hellwig 54996527980SChristoph Hellwig static void init_once(void *foo, kmem_cache_t *cachep, unsigned long flags) 55096527980SChristoph Hellwig { 55196527980SChristoph Hellwig struct hugetlbfs_inode_info *ei = (struct hugetlbfs_inode_info *)foo; 55296527980SChristoph Hellwig 55396527980SChristoph Hellwig if ((flags & (SLAB_CTOR_VERIFY|SLAB_CTOR_CONSTRUCTOR)) == 55496527980SChristoph Hellwig SLAB_CTOR_CONSTRUCTOR) 55596527980SChristoph Hellwig inode_init_once(&ei->vfs_inode); 55696527980SChristoph Hellwig } 55796527980SChristoph Hellwig 5581da177e4SLinus Torvalds struct file_operations hugetlbfs_file_operations = { 5591da177e4SLinus Torvalds .mmap = hugetlbfs_file_mmap, 5601da177e4SLinus Torvalds .fsync = simple_sync_file, 5611da177e4SLinus Torvalds .get_unmapped_area = hugetlb_get_unmapped_area, 5621da177e4SLinus Torvalds }; 5631da177e4SLinus Torvalds 5641da177e4SLinus Torvalds static struct inode_operations hugetlbfs_dir_inode_operations = { 5651da177e4SLinus Torvalds .create = hugetlbfs_create, 5661da177e4SLinus Torvalds .lookup = simple_lookup, 5671da177e4SLinus Torvalds .link = simple_link, 5681da177e4SLinus Torvalds .unlink = simple_unlink, 5691da177e4SLinus Torvalds .symlink = hugetlbfs_symlink, 5701da177e4SLinus Torvalds .mkdir = hugetlbfs_mkdir, 5711da177e4SLinus Torvalds .rmdir = simple_rmdir, 5721da177e4SLinus Torvalds .mknod = hugetlbfs_mknod, 5731da177e4SLinus Torvalds .rename = simple_rename, 5741da177e4SLinus Torvalds .setattr = hugetlbfs_setattr, 5751da177e4SLinus Torvalds }; 5761da177e4SLinus Torvalds 5771da177e4SLinus Torvalds static struct inode_operations hugetlbfs_inode_operations = { 5781da177e4SLinus Torvalds .setattr = hugetlbfs_setattr, 5791da177e4SLinus Torvalds }; 5801da177e4SLinus Torvalds 5811da177e4SLinus Torvalds static struct super_operations hugetlbfs_ops = { 5821da177e4SLinus Torvalds .alloc_inode = hugetlbfs_alloc_inode, 5831da177e4SLinus Torvalds .destroy_inode = hugetlbfs_destroy_inode, 5841da177e4SLinus Torvalds .statfs = hugetlbfs_statfs, 585149f4211SChristoph Hellwig .delete_inode = hugetlbfs_delete_inode, 5861da177e4SLinus Torvalds .drop_inode = hugetlbfs_drop_inode, 5871da177e4SLinus Torvalds .put_super = hugetlbfs_put_super, 5881da177e4SLinus Torvalds }; 5891da177e4SLinus Torvalds 5901da177e4SLinus Torvalds static int 5911da177e4SLinus Torvalds hugetlbfs_parse_options(char *options, struct hugetlbfs_config *pconfig) 5921da177e4SLinus Torvalds { 5931da177e4SLinus Torvalds char *opt, *value, *rest; 5941da177e4SLinus Torvalds 5951da177e4SLinus Torvalds if (!options) 5961da177e4SLinus Torvalds return 0; 5971da177e4SLinus Torvalds while ((opt = strsep(&options, ",")) != NULL) { 5981da177e4SLinus Torvalds if (!*opt) 5991da177e4SLinus Torvalds continue; 6001da177e4SLinus Torvalds 6011da177e4SLinus Torvalds value = strchr(opt, '='); 6021da177e4SLinus Torvalds if (!value || !*value) 6031da177e4SLinus Torvalds return -EINVAL; 6041da177e4SLinus Torvalds else 6051da177e4SLinus Torvalds *value++ = '\0'; 6061da177e4SLinus Torvalds 6071da177e4SLinus Torvalds if (!strcmp(opt, "uid")) 6081da177e4SLinus Torvalds pconfig->uid = simple_strtoul(value, &value, 0); 6091da177e4SLinus Torvalds else if (!strcmp(opt, "gid")) 6101da177e4SLinus Torvalds pconfig->gid = simple_strtoul(value, &value, 0); 6111da177e4SLinus Torvalds else if (!strcmp(opt, "mode")) 6121da177e4SLinus Torvalds pconfig->mode = simple_strtoul(value,&value,0) & 0777U; 6131da177e4SLinus Torvalds else if (!strcmp(opt, "size")) { 6141da177e4SLinus Torvalds unsigned long long size = memparse(value, &rest); 6151da177e4SLinus Torvalds if (*rest == '%') { 6161da177e4SLinus Torvalds size <<= HPAGE_SHIFT; 6171da177e4SLinus Torvalds size *= max_huge_pages; 6181da177e4SLinus Torvalds do_div(size, 100); 6191da177e4SLinus Torvalds rest++; 6201da177e4SLinus Torvalds } 6211da177e4SLinus Torvalds size &= HPAGE_MASK; 6221da177e4SLinus Torvalds pconfig->nr_blocks = (size >> HPAGE_SHIFT); 6231da177e4SLinus Torvalds value = rest; 6241da177e4SLinus Torvalds } else if (!strcmp(opt,"nr_inodes")) { 6251da177e4SLinus Torvalds pconfig->nr_inodes = memparse(value, &rest); 6261da177e4SLinus Torvalds value = rest; 6271da177e4SLinus Torvalds } else 6281da177e4SLinus Torvalds return -EINVAL; 6291da177e4SLinus Torvalds 6301da177e4SLinus Torvalds if (*value) 6311da177e4SLinus Torvalds return -EINVAL; 6321da177e4SLinus Torvalds } 6331da177e4SLinus Torvalds return 0; 6341da177e4SLinus Torvalds } 6351da177e4SLinus Torvalds 6361da177e4SLinus Torvalds static int 6371da177e4SLinus Torvalds hugetlbfs_fill_super(struct super_block *sb, void *data, int silent) 6381da177e4SLinus Torvalds { 6391da177e4SLinus Torvalds struct inode * inode; 6401da177e4SLinus Torvalds struct dentry * root; 6411da177e4SLinus Torvalds int ret; 6421da177e4SLinus Torvalds struct hugetlbfs_config config; 6431da177e4SLinus Torvalds struct hugetlbfs_sb_info *sbinfo; 6441da177e4SLinus Torvalds 6451da177e4SLinus Torvalds config.nr_blocks = -1; /* No limit on size by default */ 6461da177e4SLinus Torvalds config.nr_inodes = -1; /* No limit on number of inodes by default */ 6471da177e4SLinus Torvalds config.uid = current->fsuid; 6481da177e4SLinus Torvalds config.gid = current->fsgid; 6491da177e4SLinus Torvalds config.mode = 0755; 6501da177e4SLinus Torvalds ret = hugetlbfs_parse_options(data, &config); 6511da177e4SLinus Torvalds 6521da177e4SLinus Torvalds if (ret) 6531da177e4SLinus Torvalds return ret; 6541da177e4SLinus Torvalds 6551da177e4SLinus Torvalds sbinfo = kmalloc(sizeof(struct hugetlbfs_sb_info), GFP_KERNEL); 6561da177e4SLinus Torvalds if (!sbinfo) 6571da177e4SLinus Torvalds return -ENOMEM; 6581da177e4SLinus Torvalds sb->s_fs_info = sbinfo; 6591da177e4SLinus Torvalds spin_lock_init(&sbinfo->stat_lock); 6601da177e4SLinus Torvalds sbinfo->max_blocks = config.nr_blocks; 6611da177e4SLinus Torvalds sbinfo->free_blocks = config.nr_blocks; 6621da177e4SLinus Torvalds sbinfo->max_inodes = config.nr_inodes; 6631da177e4SLinus Torvalds sbinfo->free_inodes = config.nr_inodes; 6641da177e4SLinus Torvalds sb->s_maxbytes = MAX_LFS_FILESIZE; 6651da177e4SLinus Torvalds sb->s_blocksize = HPAGE_SIZE; 6661da177e4SLinus Torvalds sb->s_blocksize_bits = HPAGE_SHIFT; 6671da177e4SLinus Torvalds sb->s_magic = HUGETLBFS_MAGIC; 6681da177e4SLinus Torvalds sb->s_op = &hugetlbfs_ops; 6691da177e4SLinus Torvalds sb->s_time_gran = 1; 6701da177e4SLinus Torvalds inode = hugetlbfs_get_inode(sb, config.uid, config.gid, 6711da177e4SLinus Torvalds S_IFDIR | config.mode, 0); 6721da177e4SLinus Torvalds if (!inode) 6731da177e4SLinus Torvalds goto out_free; 6741da177e4SLinus Torvalds 6751da177e4SLinus Torvalds root = d_alloc_root(inode); 6761da177e4SLinus Torvalds if (!root) { 6771da177e4SLinus Torvalds iput(inode); 6781da177e4SLinus Torvalds goto out_free; 6791da177e4SLinus Torvalds } 6801da177e4SLinus Torvalds sb->s_root = root; 6811da177e4SLinus Torvalds return 0; 6821da177e4SLinus Torvalds out_free: 6831da177e4SLinus Torvalds kfree(sbinfo); 6841da177e4SLinus Torvalds return -ENOMEM; 6851da177e4SLinus Torvalds } 6861da177e4SLinus Torvalds 6871da177e4SLinus Torvalds int hugetlb_get_quota(struct address_space *mapping) 6881da177e4SLinus Torvalds { 6891da177e4SLinus Torvalds int ret = 0; 6901da177e4SLinus Torvalds struct hugetlbfs_sb_info *sbinfo = HUGETLBFS_SB(mapping->host->i_sb); 6911da177e4SLinus Torvalds 6921da177e4SLinus Torvalds if (sbinfo->free_blocks > -1) { 6931da177e4SLinus Torvalds spin_lock(&sbinfo->stat_lock); 6941da177e4SLinus Torvalds if (sbinfo->free_blocks > 0) 6951da177e4SLinus Torvalds sbinfo->free_blocks--; 6961da177e4SLinus Torvalds else 6971da177e4SLinus Torvalds ret = -ENOMEM; 6981da177e4SLinus Torvalds spin_unlock(&sbinfo->stat_lock); 6991da177e4SLinus Torvalds } 7001da177e4SLinus Torvalds 7011da177e4SLinus Torvalds return ret; 7021da177e4SLinus Torvalds } 7031da177e4SLinus Torvalds 7041da177e4SLinus Torvalds void hugetlb_put_quota(struct address_space *mapping) 7051da177e4SLinus Torvalds { 7061da177e4SLinus Torvalds struct hugetlbfs_sb_info *sbinfo = HUGETLBFS_SB(mapping->host->i_sb); 7071da177e4SLinus Torvalds 7081da177e4SLinus Torvalds if (sbinfo->free_blocks > -1) { 7091da177e4SLinus Torvalds spin_lock(&sbinfo->stat_lock); 7101da177e4SLinus Torvalds sbinfo->free_blocks++; 7111da177e4SLinus Torvalds spin_unlock(&sbinfo->stat_lock); 7121da177e4SLinus Torvalds } 7131da177e4SLinus Torvalds } 7141da177e4SLinus Torvalds 7151da177e4SLinus Torvalds static struct super_block *hugetlbfs_get_sb(struct file_system_type *fs_type, 7161da177e4SLinus Torvalds int flags, const char *dev_name, void *data) 7171da177e4SLinus Torvalds { 7181da177e4SLinus Torvalds return get_sb_nodev(fs_type, flags, data, hugetlbfs_fill_super); 7191da177e4SLinus Torvalds } 7201da177e4SLinus Torvalds 7211da177e4SLinus Torvalds static struct file_system_type hugetlbfs_fs_type = { 7221da177e4SLinus Torvalds .name = "hugetlbfs", 7231da177e4SLinus Torvalds .get_sb = hugetlbfs_get_sb, 7241da177e4SLinus Torvalds .kill_sb = kill_litter_super, 7251da177e4SLinus Torvalds }; 7261da177e4SLinus Torvalds 7271da177e4SLinus Torvalds static struct vfsmount *hugetlbfs_vfsmount; 7281da177e4SLinus Torvalds 7291da177e4SLinus Torvalds /* 7301da177e4SLinus Torvalds * Return the next identifier for a shm file 7311da177e4SLinus Torvalds */ 7321da177e4SLinus Torvalds static unsigned long hugetlbfs_counter(void) 7331da177e4SLinus Torvalds { 7341da177e4SLinus Torvalds static DEFINE_SPINLOCK(lock); 7351da177e4SLinus Torvalds static unsigned long counter; 7361da177e4SLinus Torvalds unsigned long ret; 7371da177e4SLinus Torvalds 7381da177e4SLinus Torvalds spin_lock(&lock); 7391da177e4SLinus Torvalds ret = ++counter; 7401da177e4SLinus Torvalds spin_unlock(&lock); 7411da177e4SLinus Torvalds return ret; 7421da177e4SLinus Torvalds } 7431da177e4SLinus Torvalds 7441da177e4SLinus Torvalds static int can_do_hugetlb_shm(void) 7451da177e4SLinus Torvalds { 7461da177e4SLinus Torvalds return likely(capable(CAP_IPC_LOCK) || 7471da177e4SLinus Torvalds in_group_p(sysctl_hugetlb_shm_group) || 7481da177e4SLinus Torvalds can_do_mlock()); 7491da177e4SLinus Torvalds } 7501da177e4SLinus Torvalds 7511da177e4SLinus Torvalds struct file *hugetlb_zero_setup(size_t size) 7521da177e4SLinus Torvalds { 7531da177e4SLinus Torvalds int error = -ENOMEM; 7541da177e4SLinus Torvalds struct file *file; 7551da177e4SLinus Torvalds struct inode *inode; 7561da177e4SLinus Torvalds struct dentry *dentry, *root; 7571da177e4SLinus Torvalds struct qstr quick_string; 7581da177e4SLinus Torvalds char buf[16]; 7591da177e4SLinus Torvalds 7601da177e4SLinus Torvalds if (!can_do_hugetlb_shm()) 7611da177e4SLinus Torvalds return ERR_PTR(-EPERM); 7621da177e4SLinus Torvalds 7631da177e4SLinus Torvalds if (!is_hugepage_mem_enough(size)) 7641da177e4SLinus Torvalds return ERR_PTR(-ENOMEM); 7651da177e4SLinus Torvalds 7661da177e4SLinus Torvalds if (!user_shm_lock(size, current->user)) 7671da177e4SLinus Torvalds return ERR_PTR(-ENOMEM); 7681da177e4SLinus Torvalds 7691da177e4SLinus Torvalds root = hugetlbfs_vfsmount->mnt_root; 7701da177e4SLinus Torvalds snprintf(buf, 16, "%lu", hugetlbfs_counter()); 7711da177e4SLinus Torvalds quick_string.name = buf; 7721da177e4SLinus Torvalds quick_string.len = strlen(quick_string.name); 7731da177e4SLinus Torvalds quick_string.hash = 0; 7741da177e4SLinus Torvalds dentry = d_alloc(root, &quick_string); 7751da177e4SLinus Torvalds if (!dentry) 7761da177e4SLinus Torvalds goto out_shm_unlock; 7771da177e4SLinus Torvalds 7781da177e4SLinus Torvalds error = -ENFILE; 7791da177e4SLinus Torvalds file = get_empty_filp(); 7801da177e4SLinus Torvalds if (!file) 7811da177e4SLinus Torvalds goto out_dentry; 7821da177e4SLinus Torvalds 7831da177e4SLinus Torvalds error = -ENOSPC; 7841da177e4SLinus Torvalds inode = hugetlbfs_get_inode(root->d_sb, current->fsuid, 7851da177e4SLinus Torvalds current->fsgid, S_IFREG | S_IRWXUGO, 0); 7861da177e4SLinus Torvalds if (!inode) 7871da177e4SLinus Torvalds goto out_file; 7881da177e4SLinus Torvalds 7891da177e4SLinus Torvalds d_instantiate(dentry, inode); 7901da177e4SLinus Torvalds inode->i_size = size; 7911da177e4SLinus Torvalds inode->i_nlink = 0; 7921da177e4SLinus Torvalds file->f_vfsmnt = mntget(hugetlbfs_vfsmount); 7931da177e4SLinus Torvalds file->f_dentry = dentry; 7941da177e4SLinus Torvalds file->f_mapping = inode->i_mapping; 7951da177e4SLinus Torvalds file->f_op = &hugetlbfs_file_operations; 7961da177e4SLinus Torvalds file->f_mode = FMODE_WRITE | FMODE_READ; 7971da177e4SLinus Torvalds return file; 7981da177e4SLinus Torvalds 7991da177e4SLinus Torvalds out_file: 8001da177e4SLinus Torvalds put_filp(file); 8011da177e4SLinus Torvalds out_dentry: 8021da177e4SLinus Torvalds dput(dentry); 8031da177e4SLinus Torvalds out_shm_unlock: 8041da177e4SLinus Torvalds user_shm_unlock(size, current->user); 8051da177e4SLinus Torvalds return ERR_PTR(error); 8061da177e4SLinus Torvalds } 8071da177e4SLinus Torvalds 8081da177e4SLinus Torvalds static int __init init_hugetlbfs_fs(void) 8091da177e4SLinus Torvalds { 8101da177e4SLinus Torvalds int error; 8111da177e4SLinus Torvalds struct vfsmount *vfsmount; 8121da177e4SLinus Torvalds 8131da177e4SLinus Torvalds hugetlbfs_inode_cachep = kmem_cache_create("hugetlbfs_inode_cache", 8141da177e4SLinus Torvalds sizeof(struct hugetlbfs_inode_info), 8151da177e4SLinus Torvalds 0, 0, init_once, NULL); 8161da177e4SLinus Torvalds if (hugetlbfs_inode_cachep == NULL) 8171da177e4SLinus Torvalds return -ENOMEM; 8181da177e4SLinus Torvalds 8191da177e4SLinus Torvalds error = register_filesystem(&hugetlbfs_fs_type); 8201da177e4SLinus Torvalds if (error) 8211da177e4SLinus Torvalds goto out; 8221da177e4SLinus Torvalds 8231da177e4SLinus Torvalds vfsmount = kern_mount(&hugetlbfs_fs_type); 8241da177e4SLinus Torvalds 8251da177e4SLinus Torvalds if (!IS_ERR(vfsmount)) { 8261da177e4SLinus Torvalds hugetlbfs_vfsmount = vfsmount; 8271da177e4SLinus Torvalds return 0; 8281da177e4SLinus Torvalds } 8291da177e4SLinus Torvalds 8301da177e4SLinus Torvalds error = PTR_ERR(vfsmount); 8311da177e4SLinus Torvalds 8321da177e4SLinus Torvalds out: 8331da177e4SLinus Torvalds if (error) 8341da177e4SLinus Torvalds kmem_cache_destroy(hugetlbfs_inode_cachep); 8351da177e4SLinus Torvalds return error; 8361da177e4SLinus Torvalds } 8371da177e4SLinus Torvalds 8381da177e4SLinus Torvalds static void __exit exit_hugetlbfs_fs(void) 8391da177e4SLinus Torvalds { 8401da177e4SLinus Torvalds kmem_cache_destroy(hugetlbfs_inode_cachep); 8411da177e4SLinus Torvalds unregister_filesystem(&hugetlbfs_fs_type); 8421da177e4SLinus Torvalds } 8431da177e4SLinus Torvalds 8441da177e4SLinus Torvalds module_init(init_hugetlbfs_fs) 8451da177e4SLinus Torvalds module_exit(exit_hugetlbfs_fs) 8461da177e4SLinus Torvalds 8471da177e4SLinus Torvalds MODULE_LICENSE("GPL"); 848