shm: fix the filename of hugetlb sysv shared memory
[safe/jmp/linux-2.6] / fs / hugetlbfs / inode.c
index ab4c3a9..e6b46b3 100644 (file)
@@ -22,6 +22,7 @@
 #include <linux/backing-dev.h>
 #include <linux/hugetlb.h>
 #include <linux/pagevec.h>
+#include <linux/mman.h>
 #include <linux/quotaops.h>
 #include <linux/slab.h>
 #include <linux/dnotify.h>
 /* some random number */
 #define HUGETLBFS_MAGIC        0x958458f6
 
-static struct super_operations hugetlbfs_ops;
-static struct address_space_operations hugetlbfs_aops;
-struct file_operations hugetlbfs_file_operations;
-static struct inode_operations hugetlbfs_dir_inode_operations;
-static struct inode_operations hugetlbfs_inode_operations;
+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;
 
 static struct backing_dev_info hugetlbfs_backing_dev_info = {
        .ra_pages       = 0,    /* No readahead */
@@ -56,82 +57,37 @@ static void huge_pagevec_release(struct pagevec *pvec)
        pagevec_reinit(pvec);
 }
 
-/*
- * huge_pages_needed tries to determine the number of new huge pages that
- * will be required to fully populate this VMA.  This will be equal to
- * the size of the VMA in huge pages minus the number of huge pages
- * (covered by this VMA) that are found in the page cache.
- *
- * Result is in bytes to be compatible with is_hugepage_mem_enough()
- */
-static unsigned long
-huge_pages_needed(struct address_space *mapping, struct vm_area_struct *vma)
-{
-       int i;
-       struct pagevec pvec;
-       unsigned long start = vma->vm_start;
-       unsigned long end = vma->vm_end;
-       unsigned long hugepages = (end - start) >> HPAGE_SHIFT;
-       pgoff_t next = vma->vm_pgoff;
-       pgoff_t endpg = next + ((end - start) >> PAGE_SHIFT);
-
-       pagevec_init(&pvec, 0);
-       while (next < endpg) {
-               if (!pagevec_lookup(&pvec, mapping, next, PAGEVEC_SIZE))
-                       break;
-               for (i = 0; i < pagevec_count(&pvec); i++) {
-                       struct page *page = pvec.pages[i];
-                       if (page->index > next)
-                               next = page->index;
-                       if (page->index >= endpg)
-                               break;
-                       next++;
-                       hugepages--;
-               }
-               huge_pagevec_release(&pvec);
-       }
-       return hugepages << HPAGE_SHIFT;
-}
-
 static int hugetlbfs_file_mmap(struct file *file, struct vm_area_struct *vma)
 {
-       struct inode *inode = file->f_dentry->d_inode;
-       struct address_space *mapping = inode->i_mapping;
-       unsigned long bytes;
+       struct inode *inode = file->f_path.dentry->d_inode;
        loff_t len, vma_len;
        int ret;
 
-       if (vma->vm_pgoff & (HPAGE_SIZE / PAGE_SIZE - 1))
-               return -EINVAL;
-
-       if (vma->vm_start & ~HPAGE_MASK)
-               return -EINVAL;
-
-       if (vma->vm_end & ~HPAGE_MASK)
-               return -EINVAL;
-
-       if (vma->vm_end - vma->vm_start < HPAGE_SIZE)
-               return -EINVAL;
-
-       bytes = huge_pages_needed(mapping, vma);
-       if (!is_hugepage_mem_enough(bytes))
-               return -ENOMEM;
+       /*
+        * vma 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_RESERVED;
+       vma->vm_ops = &hugetlb_vm_ops;
 
        vma_len = (loff_t)(vma->vm_end - vma->vm_start);
 
        mutex_lock(&inode->i_mutex);
        file_accessed(file);
-       vma->vm_flags |= VM_HUGETLB | VM_RESERVED;
-       vma->vm_ops = &hugetlb_vm_ops;
 
        ret = -ENOMEM;
        len = vma_len + ((loff_t)vma->vm_pgoff << PAGE_SHIFT);
-       if (!(vma->vm_flags & VM_WRITE) && len > inode->i_size)
+
+       if (vma->vm_flags & VM_MAYSHARE &&
+           hugetlb_reserve_pages(inode, vma->vm_pgoff >> (HPAGE_SHIFT-PAGE_SHIFT),
+                                 len >> HPAGE_SHIFT))
                goto out;
 
        ret = 0;
        hugetlb_prefault_arch_hook(vma->vm_mm);
-       if (inode->i_size < len)
+       if (vma->vm_flags & VM_WRITE && inode->i_size < len)
                inode->i_size = len;
 out:
        mutex_unlock(&inode->i_mutex);
@@ -143,10 +99,7 @@ out:
  * Called under down_write(mmap_sem).
  */
 
-#ifdef HAVE_ARCH_HUGETLB_UNMAPPED_AREA
-unsigned long hugetlb_get_unmapped_area(struct file *file, unsigned long addr,
-               unsigned long len, unsigned long pgoff, unsigned long flags);
-#else
+#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)
@@ -160,6 +113,12 @@ hugetlb_get_unmapped_area(struct file *file, unsigned long addr,
        if (len > TASK_SIZE)
                return -ENOMEM;
 
+       if (flags & MAP_FIXED) {
+               if (prepare_hugepage_range(addr, len, pgoff))
+                       return -EINVAL;
+               return addr;
+       }
+
        if (addr) {
                addr = ALIGN(addr, HPAGE_SIZE);
                vma = find_vma(mm, addr);
@@ -221,18 +180,19 @@ static int hugetlbfs_commit_write(struct file *file,
 
 static void truncate_huge_page(struct page *page)
 {
-       clear_page_dirty(page);
+       cancel_dirty_page(page, /* No IO accounting for huge pages? */0);
        ClearPageUptodate(page);
        remove_from_page_cache(page);
        put_page(page);
 }
 
-static void truncate_hugepages(struct address_space *mapping, loff_t lstart)
+static void truncate_hugepages(struct inode *inode, loff_t lstart)
 {
+       struct address_space *mapping = &inode->i_data;
        const pgoff_t start = lstart >> HPAGE_SHIFT;
        struct pagevec pvec;
        pgoff_t next;
-       int i;
+       int i, freed = 0;
 
        pagevec_init(&pvec, 0);
        next = start;
@@ -254,20 +214,21 @@ static void truncate_hugepages(struct address_space *mapping, loff_t lstart)
                        truncate_huge_page(page);
                        unlock_page(page);
                        hugetlb_put_quota(mapping);
+                       freed++;
                }
                huge_pagevec_release(&pvec);
        }
        BUG_ON(!lstart && mapping->nrpages);
+       hugetlb_unreserve_pages(inode, start, freed);
 }
 
 static void hugetlbfs_delete_inode(struct inode *inode)
 {
-       if (inode->i_data.nrpages)
-               truncate_hugepages(&inode->i_data, 0);
+       truncate_hugepages(inode, 0);
        clear_inode(inode);
 }
 
-static void hugetlbfs_forget_inode(struct inode *inode)
+static void hugetlbfs_forget_inode(struct inode *inode) __releases(inode_lock)
 {
        struct super_block *sb = inode->i_sb;
 
@@ -296,8 +257,7 @@ static void hugetlbfs_forget_inode(struct inode *inode)
        inode->i_state |= I_FREEING;
        inodes_stat.nr_inodes--;
        spin_unlock(&inode_lock);
-       if (inode->i_data.nrpages)
-               truncate_hugepages(&inode->i_data, 0);
+       truncate_hugepages(inode, 0);
        clear_inode(inode);
        destroy_inode(inode);
 }
@@ -310,29 +270,27 @@ static void hugetlbfs_drop_inode(struct inode *inode)
                hugetlbfs_forget_inode(inode);
 }
 
-/*
- * h_pgoff is in HPAGE_SIZE units.
- * vma->vm_pgoff is in PAGE_SIZE units.
- */
 static inline void
-hugetlb_vmtruncate_list(struct prio_tree_root *root, unsigned long h_pgoff)
+hugetlb_vmtruncate_list(struct prio_tree_root *root, pgoff_t pgoff)
 {
        struct vm_area_struct *vma;
        struct prio_tree_iter iter;
 
-       vma_prio_tree_foreach(vma, &iter, root, h_pgoff, ULONG_MAX) {
-               unsigned long h_vm_pgoff;
+       vma_prio_tree_foreach(vma, &iter, root, pgoff, ULONG_MAX) {
                unsigned long v_offset;
 
-               h_vm_pgoff = vma->vm_pgoff >> (HPAGE_SHIFT - PAGE_SHIFT);
-               v_offset = (h_pgoff - h_vm_pgoff) << HPAGE_SHIFT;
                /*
-                * Is this VMA fully outside the truncation point?
+                * Can the expression below overflow on 32-bit arches?
+                * No, because the prio_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 (h_vm_pgoff >= h_pgoff)
+               if (vma->vm_pgoff < pgoff)
+                       v_offset = (pgoff - vma->vm_pgoff) << PAGE_SHIFT;
+               else
                        v_offset = 0;
 
-               unmap_hugepage_range(vma,
+               __unmap_hugepage_range(vma,
                                vma->vm_start + v_offset, vma->vm_end);
        }
 }
@@ -342,21 +300,21 @@ hugetlb_vmtruncate_list(struct prio_tree_root *root, unsigned long h_pgoff)
  */
 static int hugetlb_vmtruncate(struct inode *inode, loff_t offset)
 {
-       unsigned long pgoff;
+       pgoff_t pgoff;
        struct address_space *mapping = inode->i_mapping;
 
        if (offset > inode->i_size)
                return -EINVAL;
 
        BUG_ON(offset & ~HPAGE_MASK);
-       pgoff = offset >> HPAGE_SHIFT;
+       pgoff = offset >> PAGE_SHIFT;
 
        inode->i_size = offset;
        spin_lock(&mapping->i_mmap_lock);
        if (!prio_tree_empty(&mapping->i_mmap))
                hugetlb_vmtruncate_list(&mapping->i_mmap, pgoff);
        spin_unlock(&mapping->i_mmap_lock);
-       truncate_hugepages(mapping, offset);
+       truncate_hugepages(inode, offset);
        return 0;
 }
 
@@ -396,13 +354,13 @@ static struct inode *hugetlbfs_get_inode(struct super_block *sb, uid_t uid,
                inode->i_mode = mode;
                inode->i_uid = uid;
                inode->i_gid = gid;
-               inode->i_blksize = HPAGE_SIZE;
                inode->i_blocks = 0;
                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);
-               mpol_shared_policy_init(&info->policy);
+               mpol_shared_policy_init(&info->policy, MPOL_DEFAULT, NULL);
                switch (mode & S_IFMT) {
                default:
                        init_special_inode(inode, mode, dev);
@@ -416,7 +374,7 @@ static struct inode *hugetlbfs_get_inode(struct super_block *sb, uid_t uid,
                        inode->i_fop = &simple_dir_operations;
 
                        /* directory inodes start off with i_nlink == 2 (for "." entry) */
-                       inode->i_nlink++;
+                       inc_nlink(inode);
                        break;
                case S_IFLNK:
                        inode->i_op = &page_symlink_inode_operations;
@@ -457,7 +415,7 @@ static int hugetlbfs_mkdir(struct inode *dir, struct dentry *dentry, int mode)
 {
        int retval = hugetlbfs_mknod(dir, dentry, mode | S_IFDIR, 0);
        if (!retval)
-               dir->i_nlink++;
+               inc_nlink(dir);
        return retval;
 }
 
@@ -495,16 +453,19 @@ static int hugetlbfs_symlink(struct inode *dir,
 }
 
 /*
- * For direct-IO reads into hugetlb pages
+ * 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_statfs(struct super_block *sb, struct kstatfs *buf)
+static int hugetlbfs_statfs(struct dentry *dentry, struct kstatfs *buf)
 {
-       struct hugetlbfs_sb_info *sbinfo = HUGETLBFS_SB(sb);
+       struct hugetlbfs_sb_info *sbinfo = HUGETLBFS_SB(dentry->d_sb);
 
        buf->f_type = HUGETLBFS_MAGIC;
        buf->f_bsize = HPAGE_SIZE;
@@ -559,7 +520,7 @@ static void hugetlbfs_inc_free_inodes(struct hugetlbfs_sb_info *sbinfo)
 }
 
 
-static kmem_cache_t *hugetlbfs_inode_cachep;
+static struct kmem_cache *hugetlbfs_inode_cachep;
 
 static struct inode *hugetlbfs_alloc_inode(struct super_block *sb)
 {
@@ -568,7 +529,7 @@ static struct inode *hugetlbfs_alloc_inode(struct super_block *sb)
 
        if (unlikely(!hugetlbfs_dec_free_inodes(sbinfo)))
                return NULL;
-       p = kmem_cache_alloc(hugetlbfs_inode_cachep, SLAB_KERNEL);
+       p = kmem_cache_alloc(hugetlbfs_inode_cachep, GFP_KERNEL);
        if (unlikely(!p)) {
                hugetlbfs_inc_free_inodes(sbinfo);
                return NULL;
@@ -583,7 +544,7 @@ static void hugetlbfs_destroy_inode(struct inode *inode)
        kmem_cache_free(hugetlbfs_inode_cachep, HUGETLBFS_I(inode));
 }
 
-static struct address_space_operations hugetlbfs_aops = {
+static const struct address_space_operations hugetlbfs_aops = {
        .readpage       = hugetlbfs_readpage,
        .prepare_write  = hugetlbfs_prepare_write,
        .commit_write   = hugetlbfs_commit_write,
@@ -591,22 +552,20 @@ static struct address_space_operations hugetlbfs_aops = {
 };
 
 
-static void init_once(void *foo, kmem_cache_t *cachep, unsigned long flags)
+static void init_once(void *foo, struct kmem_cache *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);
+       inode_init_once(&ei->vfs_inode);
 }
 
-struct file_operations hugetlbfs_file_operations = {
+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 = {
+static const struct inode_operations hugetlbfs_dir_inode_operations = {
        .create         = hugetlbfs_create,
        .lookup         = simple_lookup,
        .link           = simple_link,
@@ -619,11 +578,11 @@ static struct inode_operations hugetlbfs_dir_inode_operations = {
        .setattr        = hugetlbfs_setattr,
 };
 
-static struct inode_operations hugetlbfs_inode_operations = {
+static const struct inode_operations hugetlbfs_inode_operations = {
        .setattr        = hugetlbfs_setattr,
 };
 
-static struct super_operations hugetlbfs_ops = {
+static const struct super_operations hugetlbfs_ops = {
        .alloc_inode    = hugetlbfs_alloc_inode,
        .destroy_inode  = hugetlbfs_destroy_inode,
        .statfs         = hugetlbfs_statfs,
@@ -663,7 +622,6 @@ hugetlbfs_parse_options(char *options, struct hugetlbfs_config *pconfig)
                                do_div(size, 100);
                                rest++;
                        }
-                       size &= HPAGE_MASK;
                        pconfig->nr_blocks = (size >> HPAGE_SHIFT);
                        value = rest;
                } else if (!strcmp(opt,"nr_inodes")) {
@@ -757,10 +715,10 @@ void hugetlb_put_quota(struct address_space *mapping)
        }
 }
 
-static struct super_block *hugetlbfs_get_sb(struct file_system_type *fs_type,
-       int flags, const char *dev_name, void *data)
+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);
+       return get_sb_nodev(fs_type, flags, data, hugetlbfs_fill_super, mnt);
 }
 
 static struct file_system_type hugetlbfs_fs_type = {
@@ -771,21 +729,6 @@ static struct file_system_type hugetlbfs_fs_type = {
 
 static struct vfsmount *hugetlbfs_vfsmount;
 
-/*
- * Return the next identifier for a shm file
- */
-static unsigned long hugetlbfs_counter(void)
-{
-       static DEFINE_SPINLOCK(lock);
-       static unsigned long counter;
-       unsigned long ret;
-
-       spin_lock(&lock);
-       ret = ++counter;
-       spin_unlock(&lock);
-       return ret;
-}
-
 static int can_do_hugetlb_shm(void)
 {
        return likely(capable(CAP_IPC_LOCK) ||
@@ -793,27 +736,25 @@ static int can_do_hugetlb_shm(void)
                        can_do_mlock());
 }
 
-struct file *hugetlb_zero_setup(size_t size)
+struct file *hugetlb_file_setup(const char *name, size_t size)
 {
        int error = -ENOMEM;
        struct file *file;
        struct inode *inode;
        struct dentry *dentry, *root;
        struct qstr quick_string;
-       char buf[16];
+
+       if (!hugetlbfs_vfsmount)
+               return ERR_PTR(-ENOENT);
 
        if (!can_do_hugetlb_shm())
                return ERR_PTR(-EPERM);
 
-       if (!is_hugepage_mem_enough(size))
-               return ERR_PTR(-ENOMEM);
-
        if (!user_shm_lock(size, current->user))
                return ERR_PTR(-ENOMEM);
 
        root = hugetlbfs_vfsmount->mnt_root;
-       snprintf(buf, 16, "%lu", hugetlbfs_counter());
-       quick_string.name = buf;
+       quick_string.name = name;
        quick_string.len = strlen(quick_string.name);
        quick_string.hash = 0;
        dentry = d_alloc(root, &quick_string);
@@ -831,16 +772,22 @@ struct file *hugetlb_zero_setup(size_t size)
        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_path.mnt = mntget(hugetlbfs_vfsmount);
+       file->f_path.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: