#include <linux/module.h>
#include <linux/init.h>
#include <linux/fs.h>
+#include <linux/xattr.h>
+#include <linux/generic_acl.h>
#include <linux/mm.h>
#include <linux/mman.h>
#include <linux/file.h>
#include <linux/namei.h>
#include <linux/ctype.h>
#include <linux/migrate.h>
+#include <linux/highmem.h>
+#include <linux/backing-dev.h>
#include <asm/uaccess.h>
#include <asm/div64.h>
static struct super_operations shmem_ops;
static const struct address_space_operations shmem_aops;
-static struct file_operations shmem_file_operations;
+static const struct file_operations shmem_file_operations;
static struct inode_operations shmem_inode_operations;
static struct inode_operations shmem_dir_inode_operations;
+static struct inode_operations shmem_special_inode_operations;
static struct vm_operations_struct shmem_vm_ops;
static struct backing_dev_info shmem_backing_dev_info __read_mostly = {
/*
* shmem_free_swp - free some swap entries in a directory
*
- * @dir: pointer to the directory
- * @edir: pointer after last entry of the directory
+ * @dir: pointer to the directory
+ * @edir: pointer after last entry of the directory
+ * @punch_lock: pointer to spinlock when needed for the holepunch case
*/
-static int shmem_free_swp(swp_entry_t *dir, swp_entry_t *edir)
+static int shmem_free_swp(swp_entry_t *dir, swp_entry_t *edir,
+ spinlock_t *punch_lock)
{
+ spinlock_t *punch_unlock = NULL;
swp_entry_t *ptr;
int freed = 0;
for (ptr = dir; ptr < edir; ptr++) {
if (ptr->val) {
+ if (unlikely(punch_lock)) {
+ punch_unlock = punch_lock;
+ punch_lock = NULL;
+ spin_lock(punch_unlock);
+ if (!ptr->val)
+ continue;
+ }
free_swap_and_cache(*ptr);
*ptr = (swp_entry_t){0};
freed++;
}
}
+ if (punch_unlock)
+ spin_unlock(punch_unlock);
return freed;
}
-static int shmem_map_and_free_swp(struct page *subdir,
- int offset, int limit, struct page ***dir)
+static int shmem_map_and_free_swp(struct page *subdir, int offset,
+ int limit, struct page ***dir, spinlock_t *punch_lock)
{
swp_entry_t *ptr;
int freed = 0;
int size = limit - offset;
if (size > LATENCY_LIMIT)
size = LATENCY_LIMIT;
- freed += shmem_free_swp(ptr+offset, ptr+offset+size);
+ freed += shmem_free_swp(ptr+offset, ptr+offset+size,
+ punch_lock);
if (need_resched()) {
shmem_swp_unmap(ptr);
if (*dir) {
long nr_swaps_freed = 0;
int offset;
int freed;
- int punch_hole = 0;
+ int punch_hole;
+ spinlock_t *needs_lock;
+ spinlock_t *punch_lock;
+ unsigned long upper_limit;
inode->i_ctime = inode->i_mtime = CURRENT_TIME;
idx = (start + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
info->flags |= SHMEM_TRUNCATE;
if (likely(end == (loff_t) -1)) {
limit = info->next_index;
+ upper_limit = SHMEM_MAX_INDEX;
info->next_index = idx;
+ needs_lock = NULL;
+ punch_hole = 0;
} else {
- limit = (end + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
- if (limit > info->next_index)
- limit = info->next_index;
+ if (end + 1 >= inode->i_size) { /* we may free a little more */
+ limit = (inode->i_size + PAGE_CACHE_SIZE - 1) >>
+ PAGE_CACHE_SHIFT;
+ upper_limit = SHMEM_MAX_INDEX;
+ } else {
+ limit = (end + 1) >> PAGE_CACHE_SHIFT;
+ upper_limit = limit;
+ }
+ needs_lock = &info->lock;
punch_hole = 1;
}
size = limit;
if (size > SHMEM_NR_DIRECT)
size = SHMEM_NR_DIRECT;
- nr_swaps_freed = shmem_free_swp(ptr+idx, ptr+size);
+ nr_swaps_freed = shmem_free_swp(ptr+idx, ptr+size, needs_lock);
}
- if (!topdir)
+
+ /*
+ * If there are no indirect blocks or we are punching a hole
+ * below indirect blocks, nothing to be done.
+ */
+ if (!topdir || limit <= SHMEM_NR_DIRECT)
goto done2;
- BUG_ON(limit <= SHMEM_NR_DIRECT);
+ /*
+ * The truncation case has already dropped info->lock, and we're safe
+ * because i_size and next_index have already been lowered, preventing
+ * access beyond. But in the punch_hole case, we still need to take
+ * the lock when updating the swap directory, because there might be
+ * racing accesses by shmem_getpage(SGP_CACHE), shmem_unuse_inode or
+ * shmem_writepage. However, whenever we find we can remove a whole
+ * directory page (not at the misaligned start or end of the range),
+ * we first NULLify its pointer in the level above, and then have no
+ * need to take the lock when updating its contents: needs_lock and
+ * punch_lock (either pointing to info->lock or NULL) manage this.
+ */
+
+ upper_limit -= SHMEM_NR_DIRECT;
limit -= SHMEM_NR_DIRECT;
idx = (idx > SHMEM_NR_DIRECT)? (idx - SHMEM_NR_DIRECT): 0;
offset = idx % ENTRIES_PER_PAGE;
if (*dir) {
diroff = ((idx - ENTRIES_PER_PAGEPAGE/2) %
ENTRIES_PER_PAGEPAGE) / ENTRIES_PER_PAGE;
- if (!diroff && !offset) {
- *dir = NULL;
+ if (!diroff && !offset && upper_limit >= stage) {
+ if (needs_lock) {
+ spin_lock(needs_lock);
+ *dir = NULL;
+ spin_unlock(needs_lock);
+ needs_lock = NULL;
+ } else
+ *dir = NULL;
nr_pages_to_free++;
list_add(&middir->lru, &pages_to_free);
}
}
stage = idx + ENTRIES_PER_PAGEPAGE;
middir = *dir;
- *dir = NULL;
- nr_pages_to_free++;
- list_add(&middir->lru, &pages_to_free);
+ if (punch_hole)
+ needs_lock = &info->lock;
+ if (upper_limit >= stage) {
+ if (needs_lock) {
+ spin_lock(needs_lock);
+ *dir = NULL;
+ spin_unlock(needs_lock);
+ needs_lock = NULL;
+ } else
+ *dir = NULL;
+ nr_pages_to_free++;
+ list_add(&middir->lru, &pages_to_free);
+ }
shmem_dir_unmap(dir);
cond_resched();
dir = shmem_dir_map(middir);
diroff = 0;
}
+ punch_lock = needs_lock;
subdir = dir[diroff];
- if (subdir && page_private(subdir)) {
+ if (subdir && !offset && upper_limit-idx >= ENTRIES_PER_PAGE) {
+ if (needs_lock) {
+ spin_lock(needs_lock);
+ dir[diroff] = NULL;
+ spin_unlock(needs_lock);
+ punch_lock = NULL;
+ } else
+ dir[diroff] = NULL;
+ nr_pages_to_free++;
+ list_add(&subdir->lru, &pages_to_free);
+ }
+ if (subdir && page_private(subdir) /* has swap entries */) {
size = limit - idx;
if (size > ENTRIES_PER_PAGE)
size = ENTRIES_PER_PAGE;
freed = shmem_map_and_free_swp(subdir,
- offset, size, &dir);
+ offset, size, &dir, punch_lock);
if (!dir)
dir = shmem_dir_map(middir);
nr_swaps_freed += freed;
- if (offset)
+ if (offset || punch_lock) {
spin_lock(&info->lock);
- set_page_private(subdir, page_private(subdir) - freed);
- if (offset)
+ set_page_private(subdir,
+ page_private(subdir) - freed);
spin_unlock(&info->lock);
- if (!punch_hole)
- BUG_ON(page_private(subdir) > offset);
- }
- if (offset)
- offset = 0;
- else if (subdir && !page_private(subdir)) {
- dir[diroff] = NULL;
- nr_pages_to_free++;
- list_add(&subdir->lru, &pages_to_free);
+ } else
+ BUG_ON(page_private(subdir) != freed);
}
+ offset = 0;
}
done1:
shmem_dir_unmap(dir);
* generic_delete_inode did it, before we lowered next_index.
* Also, though shmem_getpage checks i_size before adding to
* cache, no recheck after: so fix the narrow window there too.
+ *
+ * Recalling truncate_inode_pages_range and unmap_mapping_range
+ * every time for punch_hole (which never got a chance to clear
+ * SHMEM_PAGEIN at the start of vmtruncate_range) is expensive,
+ * yet hardly ever necessary: try to optimize them out later.
*/
truncate_inode_pages_range(inode->i_mapping, start, end);
+ if (punch_hole)
+ unmap_mapping_range(inode->i_mapping, start,
+ end - start, 1);
}
spin_lock(&info->lock);
struct page *page = NULL;
int error;
- if (attr->ia_valid & ATTR_SIZE) {
+ if (S_ISREG(inode->i_mode) && (attr->ia_valid & ATTR_SIZE)) {
if (attr->ia_size < inode->i_size) {
/*
* If truncating down to a partial page, then
error = inode_change_ok(inode, attr);
if (!error)
error = inode_setattr(inode, attr);
+#ifdef CONFIG_TMPFS_POSIX_ACL
+ if (!error && (attr->ia_valid & ATTR_MODE))
+ error = generic_acl_chmod(inode, &shmem_acl_ops);
+#endif
if (page)
page_cache_release(page);
return error;
page_cache_release(swappage);
if (error == -ENOMEM) {
/* let kswapd refresh zone for GFP_ATOMICs */
- blk_congestion_wait(WRITE, HZ/50);
+ congestion_wait(WRITE, HZ/50);
}
goto repeat;
}
struct page *shmem_nopage(struct vm_area_struct *vma, unsigned long address, int *type)
{
- struct inode *inode = vma->vm_file->f_dentry->d_inode;
+ struct inode *inode = vma->vm_file->f_path.dentry->d_inode;
struct page *page = NULL;
unsigned long idx;
int error;
unsigned long addr, unsigned long len,
pgprot_t prot, unsigned long pgoff, int nonblock)
{
- struct inode *inode = vma->vm_file->f_dentry->d_inode;
+ struct inode *inode = vma->vm_file->f_path.dentry->d_inode;
struct mm_struct *mm = vma->vm_mm;
enum sgp_type sgp = nonblock? SGP_QUICK: SGP_CACHE;
unsigned long size;
#ifdef CONFIG_NUMA
int shmem_set_policy(struct vm_area_struct *vma, struct mempolicy *new)
{
- struct inode *i = vma->vm_file->f_dentry->d_inode;
+ struct inode *i = vma->vm_file->f_path.dentry->d_inode;
return mpol_set_shared_policy(&SHMEM_I(i)->policy, vma, new);
}
struct mempolicy *
shmem_get_policy(struct vm_area_struct *vma, unsigned long addr)
{
- struct inode *i = vma->vm_file->f_dentry->d_inode;
+ struct inode *i = vma->vm_file->f_path.dentry->d_inode;
unsigned long idx;
idx = ((addr - vma->vm_start) >> PAGE_SHIFT) + vma->vm_pgoff;
int shmem_lock(struct file *file, int lock, struct user_struct *user)
{
- struct inode *inode = file->f_dentry->d_inode;
+ struct inode *inode = file->f_path.dentry->d_inode;
struct shmem_inode_info *info = SHMEM_I(inode);
int retval = -ENOMEM;
inode->i_mapping->a_ops = &shmem_aops;
inode->i_mapping->backing_dev_info = &shmem_backing_dev_info;
inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
+ inode->i_generation = get_seconds();
info = SHMEM_I(inode);
memset(info, 0, (char *)inode - (char *)info);
spin_lock_init(&info->lock);
switch (mode & S_IFMT) {
default:
+ inode->i_op = &shmem_special_inode_operations;
init_special_inode(inode, mode, dev);
break;
case S_IFREG:
&sbinfo->policy_nodes);
break;
case S_IFDIR:
- inode->i_nlink++;
+ inc_nlink(inode);
/* Some things misbehave if size == 0 on a directory */
inode->i_size = 2 * BOGO_DIRENT_SIZE;
inode->i_op = &shmem_dir_inode_operations;
static ssize_t
shmem_file_write(struct file *file, const char __user *buf, size_t count, loff_t *ppos)
{
- struct inode *inode = file->f_dentry->d_inode;
+ struct inode *inode = file->f_path.dentry->d_inode;
loff_t pos;
unsigned long written;
ssize_t err;
if (err || !count)
goto out;
- err = remove_suid(file->f_dentry);
+ err = remove_suid(file->f_path.dentry);
if (err)
goto out;
static void do_shmem_file_read(struct file *filp, loff_t *ppos, read_descriptor_t *desc, read_actor_t actor)
{
- struct inode *inode = filp->f_dentry->d_inode;
+ struct inode *inode = filp->f_path.dentry->d_inode;
struct address_space *mapping = inode->i_mapping;
unsigned long index, offset;
iput(inode);
return error;
}
- error = 0;
+ }
+ error = shmem_acl_init(inode, dir);
+ if (error) {
+ iput(inode);
+ return error;
}
if (dir->i_mode & S_ISGID) {
inode->i_gid = dir->i_gid;
if ((error = shmem_mknod(dir, dentry, mode | S_IFDIR, 0)))
return error;
- dir->i_nlink++;
+ inc_nlink(dir);
return 0;
}
dir->i_size += BOGO_DIRENT_SIZE;
inode->i_ctime = dir->i_ctime = dir->i_mtime = CURRENT_TIME;
- inode->i_nlink++;
+ inc_nlink(inode);
atomic_inc(&inode->i_count); /* New dentry reference */
dget(dentry); /* Extra pinning count for the created dentry */
d_instantiate(dentry, inode);
dir->i_size -= BOGO_DIRENT_SIZE;
inode->i_ctime = dir->i_ctime = dir->i_mtime = CURRENT_TIME;
- inode->i_nlink--;
+ drop_nlink(inode);
dput(dentry); /* Undo the count from "create" - this does all the work */
return 0;
}
if (!simple_empty(dentry))
return -ENOTEMPTY;
- dentry->d_inode->i_nlink--;
- dir->i_nlink--;
+ drop_nlink(dentry->d_inode);
+ drop_nlink(dir);
return shmem_unlink(dir, dentry);
}
if (new_dentry->d_inode) {
(void) shmem_unlink(new_dir, new_dentry);
if (they_are_dirs)
- old_dir->i_nlink--;
+ drop_nlink(old_dir);
} else if (they_are_dirs) {
- old_dir->i_nlink--;
- new_dir->i_nlink++;
+ drop_nlink(old_dir);
+ inc_nlink(new_dir);
}
old_dir->i_size -= BOGO_DIRENT_SIZE;
.put_link = shmem_put_link,
};
+#ifdef CONFIG_TMPFS_POSIX_ACL
+/**
+ * Superblocks without xattr inode operations will get security.* xattr
+ * support from the VFS "for free". As soon as we have any other xattrs
+ * like ACLs, we also need to implement the security.* handlers at
+ * filesystem level, though.
+ */
+
+static size_t shmem_xattr_security_list(struct inode *inode, char *list,
+ size_t list_len, const char *name,
+ size_t name_len)
+{
+ return security_inode_listsecurity(inode, list, list_len);
+}
+
+static int shmem_xattr_security_get(struct inode *inode, const char *name,
+ void *buffer, size_t size)
+{
+ if (strcmp(name, "") == 0)
+ return -EINVAL;
+ return security_inode_getsecurity(inode, name, buffer, size,
+ -EOPNOTSUPP);
+}
+
+static int shmem_xattr_security_set(struct inode *inode, const char *name,
+ const void *value, size_t size, int flags)
+{
+ if (strcmp(name, "") == 0)
+ return -EINVAL;
+ return security_inode_setsecurity(inode, name, value, size, flags);
+}
+
+static struct xattr_handler shmem_xattr_security_handler = {
+ .prefix = XATTR_SECURITY_PREFIX,
+ .list = shmem_xattr_security_list,
+ .get = shmem_xattr_security_get,
+ .set = shmem_xattr_security_set,
+};
+
+static struct xattr_handler *shmem_xattr_handlers[] = {
+ &shmem_xattr_acl_access_handler,
+ &shmem_xattr_acl_default_handler,
+ &shmem_xattr_security_handler,
+ NULL
+};
+#endif
+
+static struct dentry *shmem_get_parent(struct dentry *child)
+{
+ return ERR_PTR(-ESTALE);
+}
+
+static int shmem_match(struct inode *ino, void *vfh)
+{
+ __u32 *fh = vfh;
+ __u64 inum = fh[2];
+ inum = (inum << 32) | fh[1];
+ return ino->i_ino == inum && fh[0] == ino->i_generation;
+}
+
+static struct dentry *shmem_get_dentry(struct super_block *sb, void *vfh)
+{
+ struct dentry *de = NULL;
+ struct inode *inode;
+ __u32 *fh = vfh;
+ __u64 inum = fh[2];
+ inum = (inum << 32) | fh[1];
+
+ inode = ilookup5(sb, (unsigned long)(inum+fh[0]), shmem_match, vfh);
+ if (inode) {
+ de = d_find_alias(inode);
+ iput(inode);
+ }
+
+ return de? de: ERR_PTR(-ESTALE);
+}
+
+static struct dentry *shmem_decode_fh(struct super_block *sb, __u32 *fh,
+ int len, int type,
+ int (*acceptable)(void *context, struct dentry *de),
+ void *context)
+{
+ if (len < 3)
+ return ERR_PTR(-ESTALE);
+
+ return sb->s_export_op->find_exported_dentry(sb, fh, NULL, acceptable,
+ context);
+}
+
+static int shmem_encode_fh(struct dentry *dentry, __u32 *fh, int *len,
+ int connectable)
+{
+ struct inode *inode = dentry->d_inode;
+
+ if (*len < 3)
+ return 255;
+
+ if (hlist_unhashed(&inode->i_hash)) {
+ /* Unfortunately insert_inode_hash is not idempotent,
+ * so as we hash inodes here rather than at creation
+ * time, we need a lock to ensure we only try
+ * to do it once
+ */
+ static DEFINE_SPINLOCK(lock);
+ spin_lock(&lock);
+ if (hlist_unhashed(&inode->i_hash))
+ __insert_inode_hash(inode,
+ inode->i_ino + inode->i_generation);
+ spin_unlock(&lock);
+ }
+
+ fh[0] = inode->i_generation;
+ fh[1] = inode->i_ino;
+ fh[2] = ((__u64)inode->i_ino) >> 32;
+
+ *len = 3;
+ return 1;
+}
+
+static struct export_operations shmem_export_ops = {
+ .get_parent = shmem_get_parent,
+ .get_dentry = shmem_get_dentry,
+ .encode_fh = shmem_encode_fh,
+ .decode_fh = shmem_decode_fh,
+};
+
static int shmem_parse_options(char *options, int *mode, uid_t *uid,
gid_t *gid, unsigned long *blocks, unsigned long *inodes,
int *policy, nodemask_t *policy_nodes)
&inodes, &policy, &policy_nodes))
return -EINVAL;
}
+ sb->s_export_op = &shmem_export_ops;
#else
sb->s_flags |= MS_NOUSER;
#endif
sb->s_magic = TMPFS_SUPER_MAGIC;
sb->s_op = &shmem_ops;
sb->s_time_gran = 1;
+#ifdef CONFIG_TMPFS_POSIX_ACL
+ sb->s_xattr = shmem_xattr_handlers;
+ sb->s_flags |= MS_POSIXACL;
+#endif
inode = shmem_get_inode(sb, S_IFDIR | mode, 0);
if (!inode)
static struct inode *shmem_alloc_inode(struct super_block *sb)
{
struct shmem_inode_info *p;
- p = (struct shmem_inode_info *)kmem_cache_alloc(shmem_inode_cachep, SLAB_KERNEL);
+ p = (struct shmem_inode_info *)kmem_cache_alloc(shmem_inode_cachep, GFP_KERNEL);
if (!p)
return NULL;
return &p->vfs_inode;
/* only struct inode is valid if it's an inline symlink */
mpol_free_shared_policy(&SHMEM_I(inode)->policy);
}
+ shmem_acl_destroy_inode(inode);
kmem_cache_free(shmem_inode_cachep, SHMEM_I(inode));
}
if ((flags & (SLAB_CTOR_VERIFY|SLAB_CTOR_CONSTRUCTOR)) ==
SLAB_CTOR_CONSTRUCTOR) {
inode_init_once(&p->vfs_inode);
+#ifdef CONFIG_TMPFS_POSIX_ACL
+ p->i_acl = NULL;
+ p->i_default_acl = NULL;
+#endif
}
}
static void destroy_inodecache(void)
{
- if (kmem_cache_destroy(shmem_inode_cachep))
- printk(KERN_INFO "shmem_inode_cache: not all structures were freed\n");
+ kmem_cache_destroy(shmem_inode_cachep);
}
static const struct address_space_operations shmem_aops = {
.migratepage = migrate_page,
};
-static struct file_operations shmem_file_operations = {
+static const struct file_operations shmem_file_operations = {
.mmap = shmem_mmap,
#ifdef CONFIG_TMPFS
.llseek = generic_file_llseek,
.truncate = shmem_truncate,
.setattr = shmem_notify_change,
.truncate_range = shmem_truncate_range,
+#ifdef CONFIG_TMPFS_POSIX_ACL
+ .setxattr = generic_setxattr,
+ .getxattr = generic_getxattr,
+ .listxattr = generic_listxattr,
+ .removexattr = generic_removexattr,
+ .permission = shmem_permission,
+#endif
+
};
static struct inode_operations shmem_dir_inode_operations = {
.mknod = shmem_mknod,
.rename = shmem_rename,
#endif
+#ifdef CONFIG_TMPFS_POSIX_ACL
+ .setattr = shmem_notify_change,
+ .setxattr = generic_setxattr,
+ .getxattr = generic_getxattr,
+ .listxattr = generic_listxattr,
+ .removexattr = generic_removexattr,
+ .permission = shmem_permission,
+#endif
+};
+
+static struct inode_operations shmem_special_inode_operations = {
+#ifdef CONFIG_TMPFS_POSIX_ACL
+ .setattr = shmem_notify_change,
+ .setxattr = generic_setxattr,
+ .getxattr = generic_getxattr,
+ .listxattr = generic_listxattr,
+ .removexattr = generic_removexattr,
+ .permission = shmem_permission,
+#endif
};
static struct super_operations shmem_ops = {
d_instantiate(dentry, inode);
inode->i_size = size;
inode->i_nlink = 0; /* It is unlinked */
- file->f_vfsmnt = mntget(shm_mnt);
- file->f_dentry = dentry;
+ file->f_path.mnt = mntget(shm_mnt);
+ file->f_path.dentry = dentry;
file->f_mapping = inode->i_mapping;
file->f_op = &shmem_file_operations;
file->f_mode = FMODE_WRITE | FMODE_READ;