* [PATCH][CFT] fs-specific options in /proc/mounts
2001-11-18 18:08 ` Alexander Viro
@ 2001-11-18 21:26 ` Alexander Viro
0 siblings, 0 replies; 7+ messages in thread
From: Alexander Viro @ 2001-11-18 21:26 UTC (permalink / raw)
To: linux-fsdevel
Cc: Linus Torvalds, Urban Widmark, Sven Vermeulen,
Linux-Kernel Development Mailinglist
On Sun, 18 Nov 2001, Alexander Viro wrote:
> On Sun, 18 Nov 2001, Urban Widmark wrote:
>
> > I don't know if there are any plans to change that. Wouldn't be difficult
> > to add something to super_operations.
> >
> > fs/namespace.c:
> > show_vfsmnt
> > show_nfs_mount
>
> Well, now that's easy to do. With the old code (FVO "old" equal to
> 2.4.15-pre2) you would end up with mind-boggling amount of buffer
> overruns _and_ ugly code in filesystems.
>
> I would rather start messing with that area with cleaning up mount
> options' parsers - I've got a patch that does it, it just needs to
> be ported to recent trees.
OTOH... This stuff is really trivial now, so that can easily go into
2.4.
* new superblock method: ->show_options(). It's optional and if
present - used by show_vfsmnt() (i.e. /proc/mounts) to show fs-specific
options.
* Prototype: int (*show_options)(struct seq_file *, struct vfsmount *);
Use seq_{putc,puts,printf,escape} for output (see fs/nfs/inode.c for example
of use). Pointer to seq_file describes the output buffer (first argument
of seq_...().
* Return 0 in case of success, negative - in case of fatal error
(e.g. your function needs to allocate memory and fails). read() from
/proc/mounts will fail at that point, so if you see that e.g. server is
all fucked up - say seq_puts(m, "server_all_fucked_up"); and return 0 instead
of returning -EINVAL.
* The only lock held by caller is mount_sem. Method may block,
allocate memory, cause IO, yodda, yodda. It must not call path_walk()
(e.g. filp_open() is off-limits) since that could deadlock if lookup
triggers automount.
Patch below moves handling of NFS-specific options into such
method; if you want to show some fs-specific options in your fs - add
->show_options() in your super_operations.
diff -urN S15-pre6/fs/namespace.c S15-pre6-mounts/fs/namespace.c
--- S15-pre6/fs/namespace.c Sat Nov 17 23:06:33 2001
+++ S15-pre6-mounts/fs/namespace.c Sun Nov 18 16:01:12 2001
@@ -19,9 +19,6 @@
#include <asm/uaccess.h>
-#include <linux/nfs_fs.h>
-#include <linux/nfs_fs_sb.h>
-#include <linux/nfs_mount.h>
#include <linux/seq_file.h>
struct vfsmount *do_kern_mount(char *type, int flags, char *name, void *data);
@@ -198,50 +195,10 @@
seq_escape(m, s, " \t\n\\");
}
-static void show_nfs_mount(struct seq_file *m, struct vfsmount *mnt)
-{
- static struct proc_nfs_info {
- int flag;
- char *str;
- char *nostr;
- } nfs_info[] = {
- { NFS_MOUNT_SOFT, ",soft", ",hard" },
- { NFS_MOUNT_INTR, ",intr", "" },
- { NFS_MOUNT_POSIX, ",posix", "" },
- { NFS_MOUNT_TCP, ",tcp", ",udp" },
- { NFS_MOUNT_NOCTO, ",nocto", "" },
- { NFS_MOUNT_NOAC, ",noac", "" },
- { NFS_MOUNT_NONLM, ",nolock", ",lock" },
- { NFS_MOUNT_BROKEN_SUID, ",broken_suid", "" },
- { 0, NULL, NULL }
- };
- struct proc_nfs_info *nfs_infop;
- struct nfs_server *nfss = &mnt->mnt_sb->u.nfs_sb.s_server;
-
- seq_printf(m, ",v%d", nfss->rpc_ops->version);
- seq_printf(m, ",rsize=%d", nfss->rsize);
- seq_printf(m, ",wsize=%d", nfss->wsize);
- if (nfss->acregmin != 3*HZ)
- seq_printf(m, ",acregmin=%d", nfss->acregmin/HZ);
- if (nfss->acregmax != 60*HZ)
- seq_printf(m, ",acregmax=%d", nfss->acregmax/HZ);
- if (nfss->acdirmin != 30*HZ)
- seq_printf(m, ",acdirmin=%d", nfss->acdirmin/HZ);
- if (nfss->acdirmax != 60*HZ)
- seq_printf(m, ",acdirmax=%d", nfss->acdirmax/HZ);
- for (nfs_infop = nfs_info; nfs_infop->flag; nfs_infop++) {
- if (nfss->flags & nfs_infop->flag)
- seq_puts(m, nfs_infop->str);
- else
- seq_puts(m, nfs_infop->nostr);
- }
- seq_puts(m, ",addr=");
- mangle(m, nfss->hostname);
-}
-
static int show_vfsmnt(struct seq_file *m, void *v)
{
struct vfsmount *mnt = v;
+ int err = 0;
static struct proc_fs_info {
int flag;
char *str;
@@ -281,10 +238,10 @@
if (mnt->mnt_flags & fs_infop->flag)
seq_puts(m, fs_infop->str);
}
- if (strcmp("nfs", mnt->mnt_sb->s_type->name) == 0)
- show_nfs_mount(m, mnt);
+ if (mnt->mnt_sb->s_op->show_options)
+ err = mnt->mnt_sb->s_op->show_options(m, mnt);
seq_puts(m, " 0 0\n");
- return 0;
+ return err;
}
struct seq_operations mounts_op = {
diff -urN S15-pre6/fs/nfs/inode.c S15-pre6-mounts/fs/nfs/inode.c
--- S15-pre6/fs/nfs/inode.c Sat Nov 17 23:06:33 2001
+++ S15-pre6-mounts/fs/nfs/inode.c Sun Nov 18 15:59:55 2001
@@ -32,6 +32,7 @@
#include <linux/nfs_flushd.h>
#include <linux/lockd/bind.h>
#include <linux/smp_lock.h>
+#include <linux/seq_file.h>
#include <asm/system.h>
#include <asm/uaccess.h>
@@ -51,6 +52,7 @@
static void nfs_clear_inode(struct inode *);
static void nfs_umount_begin(struct super_block *);
static int nfs_statfs(struct super_block *, struct statfs *);
+static int nfs_show_options(struct seq_file *, struct vfsmount *);
static struct super_operations nfs_sops = {
read_inode: nfs_read_inode,
@@ -60,6 +62,7 @@
statfs: nfs_statfs,
clear_inode: nfs_clear_inode,
umount_begin: nfs_umount_begin,
+ show_options: nfs_show_options,
};
/*
@@ -551,6 +554,48 @@
out_err:
printk("nfs_statfs: statfs error = %d\n", -error);
buf->f_bsize = buf->f_blocks = buf->f_bfree = buf->f_bavail = -1;
+ return 0;
+}
+
+static int nfs_show_options(struct seq_file *m, struct vfsmount *mnt)
+{
+ static struct proc_nfs_info {
+ int flag;
+ char *str;
+ char *nostr;
+ } nfs_info[] = {
+ { NFS_MOUNT_SOFT, ",soft", ",hard" },
+ { NFS_MOUNT_INTR, ",intr", "" },
+ { NFS_MOUNT_POSIX, ",posix", "" },
+ { NFS_MOUNT_TCP, ",tcp", ",udp" },
+ { NFS_MOUNT_NOCTO, ",nocto", "" },
+ { NFS_MOUNT_NOAC, ",noac", "" },
+ { NFS_MOUNT_NONLM, ",nolock", ",lock" },
+ { NFS_MOUNT_BROKEN_SUID, ",broken_suid", "" },
+ { 0, NULL, NULL }
+ };
+ struct proc_nfs_info *nfs_infop;
+ struct nfs_server *nfss = &mnt->mnt_sb->u.nfs_sb.s_server;
+
+ seq_printf(m, ",v%d", nfss->rpc_ops->version);
+ seq_printf(m, ",rsize=%d", nfss->rsize);
+ seq_printf(m, ",wsize=%d", nfss->wsize);
+ if (nfss->acregmin != 3*HZ)
+ seq_printf(m, ",acregmin=%d", nfss->acregmin/HZ);
+ if (nfss->acregmax != 60*HZ)
+ seq_printf(m, ",acregmax=%d", nfss->acregmax/HZ);
+ if (nfss->acdirmin != 30*HZ)
+ seq_printf(m, ",acdirmin=%d", nfss->acdirmin/HZ);
+ if (nfss->acdirmax != 60*HZ)
+ seq_printf(m, ",acdirmax=%d", nfss->acdirmax/HZ);
+ for (nfs_infop = nfs_info; nfs_infop->flag; nfs_infop++) {
+ if (nfss->flags & nfs_infop->flag)
+ seq_puts(m, nfs_infop->str);
+ else
+ seq_puts(m, nfs_infop->nostr);
+ }
+ seq_puts(m, ",addr=");
+ seq_escape(m, nfss->hostname, " \t\n\\");
return 0;
}
diff -urN S15-pre6/include/linux/fs.h S15-pre6-mounts/include/linux/fs.h
--- S15-pre6/include/linux/fs.h Sat Nov 17 23:06:36 2001
+++ S15-pre6-mounts/include/linux/fs.h Sun Nov 18 15:46:24 2001
@@ -853,6 +853,8 @@
int (*getattr) (struct dentry *, struct iattr *);
};
+struct seq_file;
+
/*
* NOTE: write_inode, delete_inode, clear_inode, put_inode can be called
* without the big kernel lock held in all filesystems.
@@ -904,6 +906,7 @@
*/
struct dentry * (*fh_to_dentry)(struct super_block *sb, __u32 *fh, int len, int fhtype, int parent);
int (*dentry_to_fh)(struct dentry *, __u32 *fh, int *lenp, int need_parent);
+ int (*show_options)(struct seq_file *, struct vfsmount *);
};
/* Inode state bits.. */
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