[PATCH 24/25] fsinfo: bpf - add sb operation fsinfo() [ver #14]
From: David Howells <dhowells@redhat.com>
Date: 2019-06-24 14:12:26
Also in:
linux-fsdevel, lkml
Subsystem:
bpf [general] (safe dynamic programs and tools), the rest · Maintainers:
Alexei Starovoitov, Daniel Borkmann, Andrii Nakryiko, Eduard Zingerman, Kumar Kartikeya Dwivedi, Linus Torvalds
From: Ian Kent <raven@themaw.net> The new fsinfo() system call adds a new super block operation ->fsinfo() which is used by file systems to provide file system specific information for fsinfo() requests. The fsinfo() request FSINFO_ATTR_PARAMETERS provides the same function as sb operation ->show_options() so it needs to be implemented by any file system that provides ->show_options() as a minimum. Signed-off-by: Ian Kent <raven@themaw.net> Signed-off-by: David Howells <dhowells@redhat.com> --- kernel/bpf/inode.c | 25 +++++++++++++++++++++++++ 1 file changed, 25 insertions(+)
diff --git a/kernel/bpf/inode.c b/kernel/bpf/inode.c
index 6e22363054b1..8c3575eca976 100644
--- a/kernel/bpf/inode.c
+++ b/kernel/bpf/inode.c@@ -23,6 +23,7 @@ #include <linux/filter.h> #include <linux/bpf.h> #include <linux/bpf_trace.h> +#include <linux/fsinfo.h> enum bpf_type { BPF_TYPE_UNSPEC = 0,
@@ -567,6 +568,27 @@ static int bpf_show_options(struct seq_file *m, struct dentry *root) return 0; } +#ifdef CONFIG_FSINFO +/* + * Get filesystem information. + */ +static int bpf_fsinfo(struct path *path, struct fsinfo_kparams *params) +{ + umode_t mode = d_inode(path->dentry)->i_mode & S_IALLUGO & ~S_ISVTX; + + switch (params->request) { + case FSINFO_ATTR_PARAMETERS: + fsinfo_note_sb_params(params, path->dentry->d_sb->s_flags); + if (mode != S_IRWXUGO) + fsinfo_note_paramf(params, "mode", "%o", mode); + return params->usage; + + default: + return generic_fsinfo(path, params); + } +} +#endif /* CONFIG_FSINFO */ + static void bpf_free_inode(struct inode *inode) { enum bpf_type type;
@@ -583,6 +605,9 @@ static const struct super_operations bpf_super_ops = { .drop_inode = generic_delete_inode, .show_options = bpf_show_options, .free_inode = bpf_free_inode, +#ifdef CONFIG_FSINFO + .fsinfo = bpf_fsinfo, +#endif }; enum {