From: David Howells <dhowells@redhat.com>
To: viro@zeniv.linux.org.uk
Cc: torvalds@linux-foundation.org, dhowells@redhat.com,
linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: [PATCH 3/5] vfs: Allow fsinfo() to query what's in an fs_context
Date: Wed, 01 Aug 2018 17:14:14 +0100 [thread overview]
Message-ID: <153314005462.18964.15285348846866955555.stgit@warthog.procyon.org.uk> (raw)
In-Reply-To: <153314002975.18964.1773855756473041897.stgit@warthog.procyon.org.uk>
Allow fsinfo() to be used to query the filesystem attached to an fs_context
once a superblock has been created or if it comes from fspick().
This is done with something like:
fd = fsopen("ext4", 0);
...
fsconfig(fd, fsconfig_cmd_create, ...);
fsinfo(fd, NULL, ...);
Signed-off-by: David Howells <dhowells@redhat.com>
---
fs/statfs.c | 29 ++++++++++++++++++++++++++++-
1 file changed, 28 insertions(+), 1 deletion(-)
diff --git a/fs/statfs.c b/fs/statfs.c
index 87826933faa0..2757fbaa80fb 100644
--- a/fs/statfs.c
+++ b/fs/statfs.c
@@ -667,13 +667,40 @@ static int vfs_fsinfo_path(int dfd, const char __user *filename,
return ret;
}
+static int vfs_fsinfo_fscontext(struct fs_context *fc,
+ struct fsinfo_kparams *params)
+{
+ int ret;
+
+ if (fc->ops == &legacy_fs_context_ops)
+ return -EOPNOTSUPP;
+
+ ret = mutex_lock_interruptible(&fc->uapi_mutex);
+ if (ret < 0)
+ return ret;
+
+ ret = -EIO;
+ if (fc->root) {
+ struct path path = { .dentry = fc->root };
+
+ ret = vfs_fsinfo(&path, params);
+ }
+
+ mutex_unlock(&fc->uapi_mutex);
+ return ret;
+}
+
static int vfs_fsinfo_fd(unsigned int fd, struct fsinfo_kparams *params)
{
struct fd f = fdget_raw(fd);
int ret = -EBADF;
if (f.file) {
- ret = vfs_fsinfo(&f.file->f_path, params);
+ if (f.file->f_op == &fscontext_fops)
+ ret = vfs_fsinfo_fscontext(f.file->private_data,
+ params);
+ else
+ ret = vfs_fsinfo(&f.file->f_path, params);
fdput(f);
}
return ret;
next prev parent reply other threads:[~2018-08-01 16:14 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-08-01 16:13 [PATCH 0/5] VFS: Introduce filesystem information query syscall David Howells
2018-08-01 16:14 ` [PATCH 1/5] vfs: syscall: Add fsinfo() to query filesystem information David Howells
2018-08-01 16:28 ` Theodore Y. Ts'o
2018-08-01 22:20 ` David Howells
2018-08-01 16:14 ` [PATCH 2/5] afs: Add fsinfo support David Howells
2018-08-01 16:14 ` David Howells [this message]
2018-08-01 16:14 ` [PATCH 4/5] vfs: Allow fsinfo() to be used to query an fs parameter description David Howells
2018-08-01 16:14 ` [PATCH 5/5] vfs: Implement parameter value retrieval with fsinfo() David Howells
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