@@ -81,14 +81,18 @@ long vfs_truncate(const struct path *path, loff_t length)
if (!S_ISREG(inode->i_mode))
return -EINVAL;
- error = mnt_want_write(path->mnt);
- if (error)
- goto out;
-
idmap = mnt_idmap(path->mnt);
error = inode_permission(idmap, inode, MAY_WRITE);
if (error)
- goto mnt_drop_write_and_out;
+ return error;
+
+ error = fsnotify_truncate_perm(path, length);
+ if (error)
+ return error;
+
+ error = mnt_want_write(path->mnt);
+ if (error)
+ return error;
error = -EPERM;
if (IS_APPEND(inode))
@@ -114,7 +118,7 @@ long vfs_truncate(const struct path *path, loff_t length)
put_write_access(inode);
mnt_drop_write_and_out:
mnt_drop_write(path->mnt);
-out:
+
return error;
}
EXPORT_SYMBOL_GPL(vfs_truncate);
@@ -175,11 +179,18 @@ long do_ftruncate(struct file *file, loff_t length, int small)
/* Check IS_APPEND on real upper inode */
if (IS_APPEND(file_inode(file)))
return -EPERM;
- sb_start_write(inode->i_sb);
+
error = security_file_truncate(file);
- if (!error)
- error = do_truncate(file_mnt_idmap(file), dentry, length,
- ATTR_MTIME | ATTR_CTIME, file);
+ if (error)
+ return error;
+
+ error = fsnotify_truncate_perm(&file->f_path, length);
+ if (error)
+ return error;
+
+ sb_start_write(inode->i_sb);
+ error = do_truncate(file_mnt_idmap(file), dentry, length,
+ ATTR_MTIME | ATTR_CTIME, file);
sb_end_write(inode->i_sb);
return error;
@@ -132,17 +132,14 @@ static inline int fsnotify_file(struct file *file, __u32 mask)
}
#ifdef CONFIG_FANOTIFY_ACCESS_PERMISSIONS
-static inline int fsnotify_pre_content(const struct file *file,
+static inline int fsnotify_pre_content(const struct path *path,
const loff_t *ppos, size_t count)
{
- struct inode *inode = file_inode(file);
+ struct inode *inode = d_inode(path->dentry);
struct file_range range;
const void *data;
int data_type;
- if (file->f_mode & FMODE_NONOTIFY)
- return 0;
-
/*
* Pre-content events are only reported for regular files and dirs
* if there are any pre-content event watchers on this sb.
@@ -155,18 +152,17 @@ static inline int fsnotify_pre_content(const struct file *file,
/* Report page aligned range only when pos is known */
if (ppos) {
- range.path = &file->f_path;
+ range.path = path;
range.pos = PAGE_ALIGN_DOWN(*ppos);
range.count = PAGE_ALIGN(*ppos + count) - range.pos;
data = ⦥
data_type = FSNOTIFY_EVENT_FILE_RANGE;
} else {
- data = &file->f_path;
+ data = path;
data_type = FSNOTIFY_EVENT_PATH;
}
- return fsnotify_parent(file->f_path.dentry, FS_PRE_ACCESS,
- data, data_type);
+ return fsnotify_parent(path->dentry, FS_PRE_ACCESS, data, data_type);
}
/*
@@ -184,11 +180,14 @@ static inline int fsnotify_file_area_perm(struct file *file, int perm_mask,
*/
lockdep_assert_once(file_write_not_started(file));
+ if (file->f_mode & FMODE_NONOTIFY)
+ return 0;
+
/*
* read()/write and other types of access generate pre-content events.
*/
if (perm_mask & (MAY_READ | MAY_WRITE | MAY_ACCESS | MAY_OPEN)) {
- int ret = fsnotify_pre_content(file, ppos, count);
+ int ret = fsnotify_pre_content(&file->f_path, ppos, count);
if (ret)
return ret;
@@ -204,6 +203,14 @@ static inline int fsnotify_file_area_perm(struct file *file, int perm_mask,
return fsnotify_file(file, FS_ACCESS_PERM);
}
+/*
+ * fsnotify_truncate_perm - permission hook before file truncate
+ */
+static inline int fsnotify_truncate_perm(const struct path *path, loff_t length)
+{
+ return fsnotify_pre_content(path, &length, 0);
+}
+
/*
* fsnotify_file_perm - permission hook before file access (unknown range)
*/
@@ -235,6 +242,11 @@ static inline int fsnotify_file_area_perm(struct file *file, int perm_mask,
return 0;
}
+static inline int fsnotify_truncate_perm(const struct path *path, loff_t length)
+{
+ return 0;
+}
+
static inline int fsnotify_file_perm(struct file *file, int perm_mask)
{
return 0;