/* Pretend that each entry is of this size in directory's i_size */
#define BOGO_DIRENT_SIZE 20
+struct shmem_xattr {
+ struct list_head list; /* anchored by shmem_inode_info->xattr_list */
+ char *name; /* xattr name */
+ size_t size;
+ char value[0];
+};
+
/* Flag allocation requirements to shmem_getpage and shmem_swp_alloc */
enum sgp_type {
SGP_READ, /* don't exceed i_size, don't allocate page */
} while (next);
}
-static void shmem_truncate_range(struct inode *inode, loff_t start, loff_t end)
+void shmem_truncate_range(struct inode *inode, loff_t start, loff_t end)
{
struct shmem_inode_info *info = SHMEM_I(inode);
unsigned long idx;
spinlock_t *punch_lock;
unsigned long upper_limit;
+ truncate_inode_pages_range(inode->i_mapping, start, end);
+
inode->i_ctime = inode->i_mtime = CURRENT_TIME;
idx = (start + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
if (idx >= info->next_index)
* 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);
shmem_free_pages(pages_to_free.next);
}
}
+EXPORT_SYMBOL_GPL(shmem_truncate_range);
-static int shmem_notify_change(struct dentry *dentry, struct iattr *attr)
+static int shmem_setattr(struct dentry *dentry, struct iattr *attr)
{
struct inode *inode = dentry->d_inode;
- loff_t newsize = attr->ia_size;
int error;
error = inode_change_ok(inode, attr);
if (error)
return error;
- if (S_ISREG(inode->i_mode) && (attr->ia_valid & ATTR_SIZE)
- && newsize != inode->i_size) {
+ if (S_ISREG(inode->i_mode) && (attr->ia_valid & ATTR_SIZE)) {
+ loff_t oldsize = inode->i_size;
+ loff_t newsize = attr->ia_size;
struct page *page = NULL;
- if (newsize < inode->i_size) {
+ if (newsize < oldsize) {
/*
* If truncating down to a partial page, then
* if that page is already allocated, hold it
spin_unlock(&info->lock);
}
}
-
- /* XXX(truncate): truncate_setsize should be called last */
- truncate_setsize(inode, newsize);
+ if (newsize != oldsize) {
+ i_size_write(inode, newsize);
+ inode->i_ctime = inode->i_mtime = CURRENT_TIME;
+ }
+ if (newsize < oldsize) {
+ loff_t holebegin = round_up(newsize, PAGE_SIZE);
+ unmap_mapping_range(inode->i_mapping, holebegin, 0, 1);
+ shmem_truncate_range(inode, newsize, (loff_t)-1);
+ /* unmap again to remove racily COWed private pages */
+ unmap_mapping_range(inode->i_mapping, holebegin, 0, 1);
+ }
if (page)
page_cache_release(page);
- shmem_truncate_range(inode, newsize, (loff_t)-1);
}
setattr_copy(inode, attr);
static void shmem_evict_inode(struct inode *inode)
{
struct shmem_inode_info *info = SHMEM_I(inode);
+ struct shmem_xattr *xattr, *nxattr;
if (inode->i_mapping->a_ops == &shmem_aops) {
- truncate_inode_pages(inode->i_mapping, 0);
shmem_unacct_size(info->flags, inode->i_size);
inode->i_size = 0;
shmem_truncate_range(inode, 0, (loff_t)-1);
mutex_unlock(&shmem_swaplist_mutex);
}
}
+
+ list_for_each_entry_safe(xattr, nxattr, &info->xattr_list, list) {
+ kfree(xattr->name);
+ kfree(xattr);
+ }
BUG_ON(inode->i_blocks);
shmem_free_inode(inode->i_sb);
end_writeback(inode);
if (size > ENTRIES_PER_PAGE)
size = ENTRIES_PER_PAGE;
offset = shmem_find_swp(entry, ptr, ptr+size);
+ shmem_swp_unmap(ptr);
if (offset >= 0) {
shmem_dir_unmap(dir);
+ ptr = shmem_swp_map(subdir);
goto found;
}
- shmem_swp_unmap(ptr);
}
}
lost1:
delete_from_page_cache(page);
shmem_swp_set(info, entry, swap.val);
shmem_swp_unmap(entry);
- spin_unlock(&info->lock);
swap_shmem_alloc(swap);
+ spin_unlock(&info->lock);
BUG_ON(page_mapped(page));
swap_writepage(page, wbc);
return 0;
swappage = lookup_swap_cache(swap);
if (!swappage) {
shmem_swp_unmap(entry);
+ spin_unlock(&info->lock);
/* here we actually do the io */
- if (type && !(*type & VM_FAULT_MAJOR)) {
- __count_vm_event(PGMAJFAULT);
+ if (type)
*type |= VM_FAULT_MAJOR;
- }
- spin_unlock(&info->lock);
swappage = shmem_swapin(swap, gfp, info, idx);
if (!swappage) {
spin_lock(&info->lock);
error = shmem_getpage(inode, vmf->pgoff, &vmf->page, SGP_CACHE, &ret);
if (error)
return ((error == -ENOMEM) ? VM_FAULT_OOM : VM_FAULT_SIGBUS);
-
+ if (ret & VM_FAULT_MAJOR) {
+ count_vm_event(PGMAJFAULT);
+ mem_cgroup_count_vm_event(vma->vm_mm, PGMAJFAULT);
+ }
return ret | VM_FAULT_LOCKED;
}
spin_lock_init(&info->lock);
info->flags = flags & VM_NORESERVE;
INIT_LIST_HEAD(&info->swaplist);
+ INIT_LIST_HEAD(&info->xattr_list);
cache_no_acl(inode);
switch (mode & S_IFMT) {
info = SHMEM_I(inode);
inode->i_size = len-1;
- if (len <= (char *)inode - (char *)info) {
+ if (len <= SHMEM_SYMLINK_INLINE_LEN) {
/* do it inline */
- memcpy(info, symname, len);
+ memcpy(info->inline_symlink, symname, len);
inode->i_op = &shmem_symlink_inline_operations;
} else {
error = shmem_getpage(inode, 0, &page, SGP_WRITE, NULL);
static void *shmem_follow_link_inline(struct dentry *dentry, struct nameidata *nd)
{
- nd_set_link(nd, (char *)SHMEM_I(dentry->d_inode));
+ nd_set_link(nd, SHMEM_I(dentry->d_inode)->inline_symlink);
return NULL;
}
}
}
-static const struct inode_operations shmem_symlink_inline_operations = {
- .readlink = generic_readlink,
- .follow_link = shmem_follow_link_inline,
-};
-
-static const struct inode_operations shmem_symlink_inode_operations = {
- .readlink = generic_readlink,
- .follow_link = shmem_follow_link,
- .put_link = shmem_put_link,
-};
-
-#ifdef CONFIG_TMPFS_POSIX_ACL
+#ifdef CONFIG_TMPFS_XATTR
/*
- * Superblocks without xattr inode operations will get security.* xattr
- * support from the VFS "for free". As soon as we have any other xattrs
+ * Superblocks without xattr inode operations may get some security.* xattr
+ * support from the LSM "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 dentry *dentry, char *list,
- size_t list_len, const char *name,
- size_t name_len, int handler_flags)
+static int shmem_xattr_get(struct dentry *dentry, const char *name,
+ void *buffer, size_t size)
{
- return security_inode_listsecurity(dentry->d_inode, list, list_len);
-}
+ struct shmem_inode_info *info;
+ struct shmem_xattr *xattr;
+ int ret = -ENODATA;
-static int shmem_xattr_security_get(struct dentry *dentry, const char *name,
- void *buffer, size_t size, int handler_flags)
-{
- if (strcmp(name, "") == 0)
- return -EINVAL;
- return xattr_getsecurity(dentry->d_inode, name, buffer, size);
+ info = SHMEM_I(dentry->d_inode);
+
+ spin_lock(&info->lock);
+ list_for_each_entry(xattr, &info->xattr_list, list) {
+ if (strcmp(name, xattr->name))
+ continue;
+
+ ret = xattr->size;
+ if (buffer) {
+ if (size < xattr->size)
+ ret = -ERANGE;
+ else
+ memcpy(buffer, xattr->value, xattr->size);
+ }
+ break;
+ }
+ spin_unlock(&info->lock);
+ return ret;
}
-static int shmem_xattr_security_set(struct dentry *dentry, const char *name,
- const void *value, size_t size, int flags, int handler_flags)
+static int shmem_xattr_set(struct dentry *dentry, const char *name,
+ const void *value, size_t size, int flags)
{
- if (strcmp(name, "") == 0)
- return -EINVAL;
- return security_inode_setsecurity(dentry->d_inode, name, value,
- size, flags);
+ struct inode *inode = dentry->d_inode;
+ struct shmem_inode_info *info = SHMEM_I(inode);
+ struct shmem_xattr *xattr;
+ struct shmem_xattr *new_xattr = NULL;
+ size_t len;
+ int err = 0;
+
+ /* value == NULL means remove */
+ if (value) {
+ /* wrap around? */
+ len = sizeof(*new_xattr) + size;
+ if (len <= sizeof(*new_xattr))
+ return -ENOMEM;
+
+ new_xattr = kmalloc(len, GFP_KERNEL);
+ if (!new_xattr)
+ return -ENOMEM;
+
+ new_xattr->name = kstrdup(name, GFP_KERNEL);
+ if (!new_xattr->name) {
+ kfree(new_xattr);
+ return -ENOMEM;
+ }
+
+ new_xattr->size = size;
+ memcpy(new_xattr->value, value, size);
+ }
+
+ spin_lock(&info->lock);
+ list_for_each_entry(xattr, &info->xattr_list, list) {
+ if (!strcmp(name, xattr->name)) {
+ if (flags & XATTR_CREATE) {
+ xattr = new_xattr;
+ err = -EEXIST;
+ } else if (new_xattr) {
+ list_replace(&xattr->list, &new_xattr->list);
+ } else {
+ list_del(&xattr->list);
+ }
+ goto out;
+ }
+ }
+ if (flags & XATTR_REPLACE) {
+ xattr = new_xattr;
+ err = -ENODATA;
+ } else {
+ list_add(&new_xattr->list, &info->xattr_list);
+ xattr = NULL;
+ }
+out:
+ spin_unlock(&info->lock);
+ if (xattr)
+ kfree(xattr->name);
+ kfree(xattr);
+ return err;
}
-static const 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 const struct xattr_handler *shmem_xattr_handlers[] = {
+#ifdef CONFIG_TMPFS_POSIX_ACL
&generic_acl_access_handler,
&generic_acl_default_handler,
- &shmem_xattr_security_handler,
+#endif
NULL
};
+
+static int shmem_xattr_validate(const char *name)
+{
+ struct { const char *prefix; size_t len; } arr[] = {
+ { XATTR_SECURITY_PREFIX, XATTR_SECURITY_PREFIX_LEN },
+ { XATTR_TRUSTED_PREFIX, XATTR_TRUSTED_PREFIX_LEN }
+ };
+ int i;
+
+ for (i = 0; i < ARRAY_SIZE(arr); i++) {
+ size_t preflen = arr[i].len;
+ if (strncmp(name, arr[i].prefix, preflen) == 0) {
+ if (!name[preflen])
+ return -EINVAL;
+ return 0;
+ }
+ }
+ return -EOPNOTSUPP;
+}
+
+static ssize_t shmem_getxattr(struct dentry *dentry, const char *name,
+ void *buffer, size_t size)
+{
+ int err;
+
+ /*
+ * If this is a request for a synthetic attribute in the system.*
+ * namespace use the generic infrastructure to resolve a handler
+ * for it via sb->s_xattr.
+ */
+ if (!strncmp(name, XATTR_SYSTEM_PREFIX, XATTR_SYSTEM_PREFIX_LEN))
+ return generic_getxattr(dentry, name, buffer, size);
+
+ err = shmem_xattr_validate(name);
+ if (err)
+ return err;
+
+ return shmem_xattr_get(dentry, name, buffer, size);
+}
+
+static int shmem_setxattr(struct dentry *dentry, const char *name,
+ const void *value, size_t size, int flags)
+{
+ int err;
+
+ /*
+ * If this is a request for a synthetic attribute in the system.*
+ * namespace use the generic infrastructure to resolve a handler
+ * for it via sb->s_xattr.
+ */
+ if (!strncmp(name, XATTR_SYSTEM_PREFIX, XATTR_SYSTEM_PREFIX_LEN))
+ return generic_setxattr(dentry, name, value, size, flags);
+
+ err = shmem_xattr_validate(name);
+ if (err)
+ return err;
+
+ if (size == 0)
+ value = ""; /* empty EA, do not remove */
+
+ return shmem_xattr_set(dentry, name, value, size, flags);
+
+}
+
+static int shmem_removexattr(struct dentry *dentry, const char *name)
+{
+ int err;
+
+ /*
+ * If this is a request for a synthetic attribute in the system.*
+ * namespace use the generic infrastructure to resolve a handler
+ * for it via sb->s_xattr.
+ */
+ if (!strncmp(name, XATTR_SYSTEM_PREFIX, XATTR_SYSTEM_PREFIX_LEN))
+ return generic_removexattr(dentry, name);
+
+ err = shmem_xattr_validate(name);
+ if (err)
+ return err;
+
+ return shmem_xattr_set(dentry, name, NULL, 0, XATTR_REPLACE);
+}
+
+static bool xattr_is_trusted(const char *name)
+{
+ return !strncmp(name, XATTR_TRUSTED_PREFIX, XATTR_TRUSTED_PREFIX_LEN);
+}
+
+static ssize_t shmem_listxattr(struct dentry *dentry, char *buffer, size_t size)
+{
+ bool trusted = capable(CAP_SYS_ADMIN);
+ struct shmem_xattr *xattr;
+ struct shmem_inode_info *info;
+ size_t used = 0;
+
+ info = SHMEM_I(dentry->d_inode);
+
+ spin_lock(&info->lock);
+ list_for_each_entry(xattr, &info->xattr_list, list) {
+ size_t len;
+
+ /* skip "trusted." attributes for unprivileged callers */
+ if (!trusted && xattr_is_trusted(xattr->name))
+ continue;
+
+ len = strlen(xattr->name) + 1;
+ used += len;
+ if (buffer) {
+ if (size < used) {
+ used = -ERANGE;
+ break;
+ }
+ memcpy(buffer, xattr->name, len);
+ buffer += len;
+ }
+ }
+ spin_unlock(&info->lock);
+
+ return used;
+}
+#endif /* CONFIG_TMPFS_XATTR */
+
+static const struct inode_operations shmem_symlink_inline_operations = {
+ .readlink = generic_readlink,
+ .follow_link = shmem_follow_link_inline,
+#ifdef CONFIG_TMPFS_XATTR
+ .setxattr = shmem_setxattr,
+ .getxattr = shmem_getxattr,
+ .listxattr = shmem_listxattr,
+ .removexattr = shmem_removexattr,
+#endif
+};
+
+static const struct inode_operations shmem_symlink_inode_operations = {
+ .readlink = generic_readlink,
+ .follow_link = shmem_follow_link,
+ .put_link = shmem_put_link,
+#ifdef CONFIG_TMPFS_XATTR
+ .setxattr = shmem_setxattr,
+ .getxattr = shmem_getxattr,
+ .listxattr = shmem_listxattr,
+ .removexattr = shmem_removexattr,
#endif
+};
static struct dentry *shmem_get_parent(struct dentry *child)
{
sb->s_magic = TMPFS_MAGIC;
sb->s_op = &shmem_ops;
sb->s_time_gran = 1;
-#ifdef CONFIG_TMPFS_POSIX_ACL
+#ifdef CONFIG_TMPFS_XATTR
sb->s_xattr = shmem_xattr_handlers;
+#endif
+#ifdef CONFIG_TMPFS_POSIX_ACL
sb->s_flags |= MS_POSIXACL;
#endif
};
static const struct inode_operations shmem_inode_operations = {
- .setattr = shmem_notify_change,
+ .setattr = shmem_setattr,
.truncate_range = shmem_truncate_range,
+#ifdef CONFIG_TMPFS_XATTR
+ .setxattr = shmem_setxattr,
+ .getxattr = shmem_getxattr,
+ .listxattr = shmem_listxattr,
+ .removexattr = shmem_removexattr,
+#endif
#ifdef CONFIG_TMPFS_POSIX_ACL
- .setxattr = generic_setxattr,
- .getxattr = generic_getxattr,
- .listxattr = generic_listxattr,
- .removexattr = generic_removexattr,
.check_acl = generic_check_acl,
#endif
.mknod = shmem_mknod,
.rename = shmem_rename,
#endif
+#ifdef CONFIG_TMPFS_XATTR
+ .setxattr = shmem_setxattr,
+ .getxattr = shmem_getxattr,
+ .listxattr = shmem_listxattr,
+ .removexattr = shmem_removexattr,
+#endif
#ifdef CONFIG_TMPFS_POSIX_ACL
- .setattr = shmem_notify_change,
- .setxattr = generic_setxattr,
- .getxattr = generic_getxattr,
- .listxattr = generic_listxattr,
- .removexattr = generic_removexattr,
+ .setattr = shmem_setattr,
.check_acl = generic_check_acl,
#endif
};
static const struct inode_operations shmem_special_inode_operations = {
+#ifdef CONFIG_TMPFS_XATTR
+ .setxattr = shmem_setxattr,
+ .getxattr = shmem_getxattr,
+ .listxattr = shmem_listxattr,
+ .removexattr = shmem_removexattr,
+#endif
#ifdef CONFIG_TMPFS_POSIX_ACL
- .setattr = shmem_notify_change,
- .setxattr = generic_setxattr,
- .getxattr = generic_getxattr,
- .listxattr = generic_listxattr,
- .removexattr = generic_removexattr,
+ .setattr = shmem_setattr,
.check_acl = generic_check_acl,
#endif
};
return 0;
}
+void shmem_truncate_range(struct inode *inode, loff_t start, loff_t end)
+{
+ truncate_inode_pages_range(inode->i_mapping, start, end);
+}
+EXPORT_SYMBOL_GPL(shmem_truncate_range);
+
#ifdef CONFIG_CGROUP_MEM_RES_CTLR
/**
* mem_cgroup_get_shmem_target - find a page or entry assigned to the shmem file
vma->vm_flags |= VM_CAN_NONLINEAR;
return 0;
}
+
+/**
+ * shmem_read_mapping_page_gfp - read into page cache, using specified page allocation flags.
+ * @mapping: the page's address_space
+ * @index: the page index
+ * @gfp: the page allocator flags to use if allocating
+ *
+ * This behaves as a tmpfs "read_cache_page_gfp(mapping, index, gfp)",
+ * with any new page allocations done using the specified allocation flags.
+ * But read_cache_page_gfp() uses the ->readpage() method: which does not
+ * suit tmpfs, since it may have pages in swapcache, and needs to find those
+ * for itself; although drivers/gpu/drm i915 and ttm rely upon this support.
+ *
+ * Provide a stub for those callers to start using now, then later
+ * flesh it out to call shmem_getpage() with additional gfp mask, when
+ * shmem_file_splice_read() is added and shmem_readpage() is removed.
+ */
+struct page *shmem_read_mapping_page_gfp(struct address_space *mapping,
+ pgoff_t index, gfp_t gfp)
+{
+ return read_cache_page_gfp(mapping, index, gfp);
+}
+EXPORT_SYMBOL_GPL(shmem_read_mapping_page_gfp);
projects / firefly-linux-kernel-4.4.55.git / blobdiff