Re: [PATCH 34/38] vfs: syscall: Add fsinfo() to query filesystem information [ver #10]
flat view
From: Jann Horn <jannh@google.com>
Date: 2018-07-28 00:39:13
Also in:
linux-fsdevel, lkml
On Fri, Jul 27, 2018 at 7:36 PM David Howells [off-list ref] wrote:
Add a system call to allow filesystem information to be queried. A request value can be given to indicate the desired attribute. Support is provided for enumerating multi-value attributes.
[...]
quoted hunk ↗ jump to hunk
+static int fsinfo_generic_ids(struct dentry *dentry, + struct fsinfo_ids *p) +{
[...]
+ strcpy(p->f_fs_name, dentry->d_sb->s_type->name);
Can you use strlcpy() instead? From a quick look, I don't see anything that actually limits the size of filesystem names, even though everything in-kernel probably fits into the 16 bytes you've allocated for the name. [...]
quoted hunk ↗ jump to hunk
+static int fsinfo_generic_name_encoding(struct dentry *dentry, char *buf) +{ + static const char encoding[] = "utf8"; + + if (buf) + memcpy(buf, encoding, sizeof(encoding) - 1); + return sizeof(encoding) - 1; +}
Is this meant to be "encoding to be used by userspace" or "encoding of on-disk filenames"? If the former: That's always utf8, right? Are there any plans to create filesystems that behave differently? If the latter: This is wrong for e.g. a vfat mount that uses a codepage, right? Should the default in that case not be "I don't know"?