Re: [RFC PATCH] fs: obtain the inode generation number from vfs directly
From: "Darrick J. Wong" <djwong@kernel.org>
Date: 2024-08-27 02:13:00
Also in:
linux-fsdevel
On Tue, Aug 27, 2024 at 01:41:08AM +0000, Hongbo Li wrote:
Many mainstream file systems already support the GETVERSION ioctl, and their implementations are completely the same, essentially just obtain the value of i_generation. We think this ioctl can be implemented at the VFS layer, so the file systems do not need to implement it individually.
What if a filesystem never touches i_generation? Is it ok to advertise a generation number of zero when that's really meaningless? Or should we gate the generic ioctl on (say) whether or not the fs implements file handles and/or supports nfs? --D
quoted hunk ↗ jump to hunk
Signed-off-by: Hongbo Li <lihongbo22@huawei.com> --- fs/ioctl.c | 6 ++++++ 1 file changed, 6 insertions(+)diff --git a/fs/ioctl.c b/fs/ioctl.c index 64776891120c..dff887ec52c4 100644 --- a/fs/ioctl.c +++ b/fs/ioctl.c@@ -878,6 +878,9 @@ static int do_vfs_ioctl(struct file *filp, unsigned int fd, case FS_IOC_GETFSUUID: return ioctl_getfsuuid(filp, argp); + case FS_IOC_GETVERSION: + return put_user(inode->i_generation, (int __user *)argp); + case FS_IOC_GETFSSYSFSPATH: return ioctl_get_fs_sysfs_path(filp, argp);@@ -992,6 +995,9 @@ COMPAT_SYSCALL_DEFINE3(ioctl, unsigned int, fd, unsigned int, cmd, cmd = (cmd == FS_IOC32_GETFLAGS) ? FS_IOC_GETFLAGS : FS_IOC_SETFLAGS; fallthrough; + case FS_IOC32_GETVERSION: + cmd = FS_IOC_GETVERSION; + fallthrough; /* * everything else in do_vfs_ioctl() takes either a compatible * pointer argument or no argument -- call it with a modified-- 2.34.1