From: David Howells Date: Thu, 20 Dec 2012 21:52:36 +0000 (+0000) Subject: VFS: Make more complete truncate operation available to CacheFiles X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=a02de9608595c8ef649ef03ae735b0b45e3d4396;p=GitHub%2Fexynos8895%2Fandroid_kernel_samsung_universal8895.git VFS: Make more complete truncate operation available to CacheFiles Make a more complete truncate operation available to CacheFiles (including security checks and suchlike) so that it can use this to clear invalidated cache files. Signed-off-by: David Howells Acked-by: Al Viro --- diff --git a/fs/open.c b/fs/open.c index 182d8667b7bd..c819bbdab47f 100644 --- a/fs/open.c +++ b/fs/open.c @@ -61,33 +61,22 @@ int do_truncate(struct dentry *dentry, loff_t length, unsigned int time_attrs, return ret; } -static long do_sys_truncate(const char __user *pathname, loff_t length) +long vfs_truncate(struct path *path, loff_t length) { - struct path path; struct inode *inode; - int error; - - error = -EINVAL; - if (length < 0) /* sorry, but loff_t says... */ - goto out; + long error; - error = user_path(pathname, &path); - if (error) - goto out; - inode = path.dentry->d_inode; + inode = path->dentry->d_inode; /* For directories it's -EISDIR, for other non-regulars - -EINVAL */ - error = -EISDIR; if (S_ISDIR(inode->i_mode)) - goto dput_and_out; - - error = -EINVAL; + return -EISDIR; if (!S_ISREG(inode->i_mode)) - goto dput_and_out; + return -EINVAL; - error = mnt_want_write(path.mnt); + error = mnt_want_write(path->mnt); if (error) - goto dput_and_out; + goto out; error = inode_permission(inode, MAY_WRITE); if (error) @@ -111,19 +100,34 @@ static long do_sys_truncate(const char __user *pathname, loff_t length) error = locks_verify_truncate(inode, NULL, length); if (!error) - error = security_path_truncate(&path); + error = security_path_truncate(path); if (!error) - error = do_truncate(path.dentry, length, 0, NULL); + error = do_truncate(path->dentry, length, 0, NULL); put_write_and_out: put_write_access(inode); mnt_drop_write_and_out: - mnt_drop_write(path.mnt); -dput_and_out: - path_put(&path); + mnt_drop_write(path->mnt); out: return error; } +EXPORT_SYMBOL_GPL(vfs_truncate); + +static long do_sys_truncate(const char __user *pathname, loff_t length) +{ + struct path path; + int error; + + if (length < 0) /* sorry, but loff_t says... */ + return -EINVAL; + + error = user_path(pathname, &path); + if (!error) { + error = vfs_truncate(&path, length); + path_put(&path); + } + return error; +} SYSCALL_DEFINE2(truncate, const char __user *, path, long, length) { diff --git a/include/linux/fs.h b/include/linux/fs.h index a823d4be38e7..017a15b707e2 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -1999,6 +1999,7 @@ struct filename { bool separate; /* should "name" be freed? */ }; +extern long vfs_truncate(struct path *, loff_t); extern int do_truncate(struct dentry *, loff_t start, unsigned int time_attrs, struct file *filp); extern int do_fallocate(struct file *file, int mode, loff_t offset,