From: David Howells <dhowells@redhat.com>
To: viro@zeniv.linux.org.uk
Cc: dhowells@redhat.com, raven@themaw.net, mszeredi@redhat.com,
linux-api@vger.kernel.org, linux-fsdevel@vger.kernel.org,
linux-kernel@vger.kernel.org
Subject: [PATCH 20/25] fsinfo: shmem - add tmpfs sb operation fsinfo() [ver #14]
Date: Mon, 24 Jun 2019 15:11:47 +0100 [thread overview]
Message-ID: <156138550754.25627.3434495073988452560.stgit@warthog.procyon.org.uk> (raw)
In-Reply-To: <156138532485.25627.7459410522109581052.stgit@warthog.procyon.org.uk>
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.
Also add a simple FSINFO_ATTR_CAPABILITIES implementation.
Signed-off-by: Ian Kent <raven@themaw.net>
Signed-off-by: David Howells <dhowells@redhat.com>
---
mm/shmem.c | 72 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 72 insertions(+)
diff --git a/mm/shmem.c b/mm/shmem.c
index 38a77ee13db1..1a660ca7042f 100644
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -39,6 +39,7 @@
#include <linux/frontswap.h>
#include <linux/fs_context.h>
#include <linux/fs_parser.h>
+#include <linux/fsinfo.h>
#include <asm/tlbflush.h> /* for arch/microblaze update_mmu_cache() */
@@ -1403,6 +1404,20 @@ static void shmem_show_mpol(struct seq_file *seq, struct mempolicy *mpol)
seq_printf(seq, ",mpol=%s", buffer);
}
+#ifdef CONFIG_FSINFO
+static void shmem_fsinfo_mpol(struct fsinfo_kparams *params, struct mempolicy *mpol)
+{
+ char buffer[64];
+
+ if (!mpol || mpol->mode == MPOL_DEFAULT)
+ return; /* show nothing */
+
+ mpol_to_str(buffer, sizeof(buffer), mpol);
+
+ fsinfo_note_paramf(params, "mpol", "%s", buffer);
+}
+#endif
+
static struct mempolicy *shmem_get_sbmpol(struct shmem_sb_info *sbinfo)
{
struct mempolicy *mpol = NULL;
@@ -1418,6 +1433,11 @@ static struct mempolicy *shmem_get_sbmpol(struct shmem_sb_info *sbinfo)
static inline void shmem_show_mpol(struct seq_file *seq, struct mempolicy *mpol)
{
}
+#ifdef CONFIG_FSINFO
+static void shmem_fsinfo_mpol(struct fsinfo_kparams *params, struct mempolicy *mpol)
+{
+}
+#endif
static inline struct mempolicy *shmem_get_sbmpol(struct shmem_sb_info *sbinfo)
{
return NULL;
@@ -3478,7 +3498,9 @@ static int shmem_parse_param(struct fs_context *fc, struct fs_parameter *param)
struct shmem_fs_context *ctx = fc->fs_private;
struct fs_parse_result result;
unsigned long long size;
+#ifdef CONFIG_NUMA
struct mempolicy *mpol;
+#endif
char *rest;
int opt;
@@ -3623,6 +3645,53 @@ static int shmem_show_options(struct seq_file *seq, struct dentry *root)
return 0;
}
+#ifdef CONFIG_FSINFO
+static int shmem_fsinfo(struct path *path, struct fsinfo_kparams *params)
+{
+ struct shmem_sb_info *sbinfo = SHMEM_SB(path->dentry->d_sb);
+ struct fsinfo_capabilities *caps;
+
+ switch (params->request) {
+ case FSINFO_ATTR_CAPABILITIES:
+ caps = params->buffer;
+ fsinfo_set_unix_caps(caps);
+ fsinfo_set_cap(caps, FSINFO_CAP_IS_MEMORY_FS);
+ fsinfo_set_cap(caps, FSINFO_CAP_NOT_PERSISTENT);
+#ifdef CONFIG_TMPFS_XATTR
+ fsinfo_set_cap(caps, FSINFO_CAP_XATTRS);
+#endif
+ return sizeof(*caps);
+
+ case FSINFO_ATTR_PARAMETERS:
+ fsinfo_note_sb_params(params, path->dentry->d_sb->s_flags);
+ if (sbinfo->max_blocks != shmem_default_max_blocks())
+ fsinfo_note_paramf(params, "size", "%luk",
+ sbinfo->max_blocks << (PAGE_SHIFT - 10));
+ if (sbinfo->max_inodes != shmem_default_max_inodes())
+ fsinfo_note_paramf(params, "nr_inodes",
+ "%lu", sbinfo->max_inodes);
+ if (sbinfo->mode != (0777 | S_ISVTX))
+ fsinfo_note_paramf(params, "mode",
+ "%03ho", sbinfo->mode);
+ if (!uid_eq(sbinfo->uid, GLOBAL_ROOT_UID))
+ fsinfo_note_paramf(params, "uid", "%u",
+ from_kuid_munged(&init_user_ns, sbinfo->uid));
+ if (!gid_eq(sbinfo->gid, GLOBAL_ROOT_GID))
+ fsinfo_note_paramf(params, "gid", "%u",
+ from_kgid_munged(&init_user_ns, sbinfo->gid));
+#ifdef CONFIG_TRANSPARENT_HUGE_PAGECACHE
+ /* Rightly or wrongly, show huge mount option unmasked by shmem_huge */
+ if (sbinfo->huge)
+ fsinfo_note_paramf(params, "huge", "%s",
+ shmem_format_huge(sbinfo->huge));
+#endif
+ shmem_fsinfo_mpol(params, sbinfo->mpol);
+ return params->usage;
+ default:
+ return generic_fsinfo(path, params);
+ }
+}
+#endif /* CONFIG_FSINFO */
#endif /* CONFIG_TMPFS */
static void shmem_put_super(struct super_block *sb)
@@ -3854,6 +3923,9 @@ static const struct super_operations shmem_ops = {
#ifdef CONFIG_TMPFS
.statfs = shmem_statfs,
.show_options = shmem_show_options,
+#ifdef CONFIG_FSINFO
+ .fsinfo = shmem_fsinfo,
+#endif
#endif
.evict_inode = shmem_evict_inode,
.drop_inode = generic_delete_inode,
next prev parent reply other threads:[~2019-06-24 14:11 UTC|newest]
Thread overview: 45+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-06-24 14:08 [PATCH 00/25] VFS: Introduce filesystem information query syscall [ver #14] David Howells
2019-06-24 14:08 ` [PATCH 01/25] vfs: syscall: Add fsinfo() to query filesystem information " David Howells
2019-06-25 8:28 ` Christian Brauner
2019-06-26 9:49 ` David Howells
2019-06-26 9:58 ` Christian Brauner
2019-06-24 14:09 ` [PATCH 02/25] fsinfo: Add syscalls to other arches " David Howells
2019-06-25 9:31 ` Christian Brauner
2019-06-24 14:09 ` [PATCH 03/25] vfs: Allow fsinfo() to query what's in an fs_context " David Howells
2019-06-25 9:27 ` Christian Brauner
2019-06-26 10:02 ` David Howells
2019-06-26 10:06 ` Christian Brauner
2019-06-24 14:09 ` [PATCH 04/25] vfs: Allow fsinfo() to be used to query an fs parameter description " David Howells
2019-06-25 9:40 ` Christian Brauner
2019-06-24 14:09 ` [PATCH 05/25] vfs: Implement parameter value retrieval with fsinfo() " David Howells
2019-06-25 9:44 ` Christian Brauner
2019-06-24 14:09 ` [PATCH 06/25] fsinfo: Implement retrieval of LSM parameters " David Howells
2019-06-24 14:09 ` [PATCH 07/25] vfs: Introduce a non-repeating system-unique superblock ID " David Howells
2019-06-24 14:09 ` [PATCH 08/25] vfs: Allow fsinfo() to look up a mount object by " David Howells
2019-06-26 9:49 ` Christian Brauner
2019-06-24 14:10 ` [PATCH 09/25] vfs: Add mount notification count " David Howells
2019-06-26 9:52 ` Christian Brauner
2019-06-24 14:10 ` [PATCH 10/25] vfs: Allow mount information to be queried by fsinfo() " David Howells
2019-06-26 9:53 ` Christian Brauner
2019-06-24 14:10 ` [PATCH 11/25] vfs: fsinfo sample: Mount listing program " David Howells
2019-06-24 14:10 ` [PATCH 12/25] fsinfo: Add API documentation " David Howells
2019-06-24 14:10 ` [PATCH 13/25] hugetlbfs: Add support for fsinfo() " David Howells
2019-06-24 14:10 ` [PATCH 14/25] kernfs, cgroup: Add fsinfo support " David Howells
2019-06-24 14:11 ` [PATCH 15/25] fsinfo: Support SELinux superblock parameter retrieval " David Howells
2019-06-24 14:11 ` [PATCH 16/25] fsinfo: Support Smack " David Howells
2019-06-24 14:11 ` [PATCH 17/25] afs: Support fsinfo() " David Howells
2019-06-24 14:11 ` [PATCH 18/25] fsinfo: proc - add sb operation " David Howells
2019-06-24 14:11 ` [PATCH 19/25] fsinfo: autofs " David Howells
2019-06-24 14:11 ` David Howells [this message]
2019-06-24 14:11 ` [PATCH 21/25] fsinfo: devpts " David Howells
2019-06-24 14:12 ` [PATCH 22/25] fsinfo: pstore " David Howells
2019-06-24 14:12 ` [PATCH 23/25] fsinfo: debugfs " David Howells
2019-06-24 14:12 ` [PATCH 24/25] fsinfo: bpf " David Howells
2019-06-24 14:12 ` [PATCH 25/25] fsinfo: ufs " David Howells
2019-06-26 10:05 ` [PATCH 00/25] VFS: Introduce filesystem information query syscall " Christian Brauner
2019-06-26 10:42 ` Ian Kent
2019-06-26 10:47 ` Christian Brauner
2019-06-27 0:38 ` Ian Kent
2019-06-26 13:19 ` Christian Brauner
2019-06-26 14:31 ` David Howells
2019-06-26 14:50 ` Christian Brauner
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