diff options
| -rw-r--r-- | fs/open.c | 31 | ||||
| -rw-r--r-- | include/linux/fsnotify.h | 20 |
2 files changed, 41 insertions, 10 deletions
diff --git a/fs/open.c b/fs/open.c index 1a9483872e1f..d11d373dca80 100644 --- a/fs/open.c +++ b/fs/open.c @@ -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 @@ put_write_and_out: 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; diff --git a/include/linux/fsnotify.h b/include/linux/fsnotify.h index 87044acf8e79..1a9ef8f6784d 100644 --- a/include/linux/fsnotify.h +++ b/include/linux/fsnotify.h @@ -171,6 +171,21 @@ static inline int fsnotify_file_area_perm(struct file *file, int perm_mask, } /* + * fsnotify_truncate_perm - permission hook before file truncate + */ +static inline int fsnotify_truncate_perm(const struct path *path, loff_t length) +{ + struct inode *inode = d_inode(path->dentry); + + if (!(inode->i_sb->s_iflags & SB_I_ALLOW_HSM) || + !fsnotify_sb_has_priority_watchers(inode->i_sb, + FSNOTIFY_PRIO_PRE_CONTENT)) + return 0; + + return fsnotify_pre_content(path, &length, 0); +} + +/* * fsnotify_file_perm - permission hook before file access (unknown range) */ static inline int fsnotify_file_perm(struct file *file, int perm_mask) @@ -208,6 +223,11 @@ 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; |