vfs: Export file system uuid via /proc/<pid>mountinfo
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From: Aneesh Kumar K. V on 12 Jul 2010 03:20 On Mon, 12 Jul 2010 12:05:43 +0530, "Aneesh Kumar K.V" <aneesh.kumar(a)linux.vnet.ibm.com> wrote: > We add a per superblock uuid field. File systems should > update the uuid in the fill_super callback > > Signed-off-by: Aneesh Kumar K.V <aneesh.kumar(a)linux.vnet.ibm.com> > --- > fs/namespace.c | 3 +++ > include/linux/fs.h | 1 + > 2 files changed, 4 insertions(+), 0 deletions(-) > > diff --git a/fs/namespace.c b/fs/namespace.c > index 88058de..5dbdbd6 100644 > --- a/fs/namespace.c > +++ b/fs/namespace.c > @@ -871,6 +871,9 @@ static int show_mountinfo(struct seq_file *m, void *v) > if (IS_MNT_UNBINDABLE(mnt)) > seq_puts(m, " unbindable"); > > + /* print the uuid */ > + seq_printf(m, " uuid:%pU", mnt->mnt_sb->s_uuid); > + > /* Filesystem specific data */ > seq_puts(m, " - "); > show_type(m, sb); > diff --git a/include/linux/fs.h b/include/linux/fs.h > index 3103c39..5f43472 100644 > --- a/include/linux/fs.h > +++ b/include/linux/fs.h > @@ -1367,6 +1367,7 @@ struct super_block { > wait_queue_head_t s_wait_unfrozen; > > char s_id[32]; /* Informational name */ > + u8 s_uuid[16]; /* UUID */ > > void *s_fs_info; /* Filesystem private info */ > fmode_t s_mode; since it is an optional tag is it ok to do the below patch ? or does optional is a way to introduce changes across kernel version and each line is suppose to have new added fields ?. Is there a userspace tool that use /proc/<pid>/mouninfo ? diff --git a/fs/namespace.c b/fs/namespace.c index 5dbdbd6..7542959 100644 --- a/fs/namespace.c +++ b/fs/namespace.c @@ -833,6 +833,16 @@ const struct seq_operations mounts_op = { .show = show_vfsmnt }; +static int uuid_is_nil(u8 *uuid) +{ + int i; + u8 *cp = (u8 *)uuid; + + for (i = 0; i < 16; i++) + if (*cp++) return 0; /* not nil */ + return 1; /* is nil */ +} + static int show_mountinfo(struct seq_file *m, void *v) { struct proc_mounts *p = m->private; @@ -871,8 +881,9 @@ static int show_mountinfo(struct seq_file *m, void *v) if (IS_MNT_UNBINDABLE(mnt)) seq_puts(m, " unbindable"); + if (!uuid_is_nil(mnt->mnt_sb->s_uuid)) /* print the uuid */ - seq_printf(m, " uuid:%pU", mnt->mnt_sb->s_uuid); + seq_printf(m, " uuid:%pU", mnt->mnt_sb->s_uuid); /* Filesystem specific data */ seq_puts(m, " - "); -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo(a)vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
From: Miklos Szeredi on 12 Jul 2010 04:30 On Mon, 12 Jul 2010, Aneesh Kumar K. V wrote: > On Mon, 12 Jul 2010 12:05:43 +0530, "Aneesh Kumar K.V" <aneesh.kumar(a)linux.vnet.ibm.com> wrote: > > We add a per superblock uuid field. File systems should > > update the uuid in the fill_super callback > > > > Signed-off-by: Aneesh Kumar K.V <aneesh.kumar(a)linux.vnet.ibm.com> > > --- > > fs/namespace.c | 3 +++ > > include/linux/fs.h | 1 + > > 2 files changed, 4 insertions(+), 0 deletions(-) > > > > diff --git a/fs/namespace.c b/fs/namespace.c > > index 88058de..5dbdbd6 100644 > > --- a/fs/namespace.c > > +++ b/fs/namespace.c > > @@ -871,6 +871,9 @@ static int show_mountinfo(struct seq_file *m, void *v) > > if (IS_MNT_UNBINDABLE(mnt)) > > seq_puts(m, " unbindable"); > > > > + /* print the uuid */ > > + seq_printf(m, " uuid:%pU", mnt->mnt_sb->s_uuid); > > + > > /* Filesystem specific data */ > > seq_puts(m, " - "); > > show_type(m, sb); > > diff --git a/include/linux/fs.h b/include/linux/fs.h > > index 3103c39..5f43472 100644 > > --- a/include/linux/fs.h > > +++ b/include/linux/fs.h > > @@ -1367,6 +1367,7 @@ struct super_block { > > wait_queue_head_t s_wait_unfrozen; > > > > char s_id[32]; /* Informational name */ > > + u8 s_uuid[16]; /* UUID */ > > > > void *s_fs_info; /* Filesystem private info */ > > fmode_t s_mode; > > since it is an optional tag is it ok to do the below patch ? or does > optional is a way to introduce changes across kernel version and > each line is suppose to have new added fields ?. Tagged fields are optional, so yes, the patch is OK. > Is there a userspace > tool that use /proc/<pid>/mouninfo ? libmount from recent enough util-linux is using mountinfo. So mount(8) should be using it, as well as some other utilities in util-linux. Thanks, Miklos > > diff --git a/fs/namespace.c b/fs/namespace.c > index 5dbdbd6..7542959 100644 > --- a/fs/namespace.c > +++ b/fs/namespace.c > @@ -833,6 +833,16 @@ const struct seq_operations mounts_op = { > .show = show_vfsmnt > }; > > +static int uuid_is_nil(u8 *uuid) > +{ > + int i; > + u8 *cp = (u8 *)uuid; > + > + for (i = 0; i < 16; i++) > + if (*cp++) return 0; /* not nil */ > + return 1; /* is nil */ > +} > + > static int show_mountinfo(struct seq_file *m, void *v) > { > struct proc_mounts *p = m->private; > @@ -871,8 +881,9 @@ static int show_mountinfo(struct seq_file *m, void *v) > if (IS_MNT_UNBINDABLE(mnt)) > seq_puts(m, " unbindable"); > > + if (!uuid_is_nil(mnt->mnt_sb->s_uuid)) > /* print the uuid */ > - seq_printf(m, " uuid:%pU", mnt->mnt_sb->s_uuid); > + seq_printf(m, " uuid:%pU", mnt->mnt_sb->s_uuid); > > /* Filesystem specific data */ > seq_puts(m, " - "); > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo(a)vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
From: Aneesh Kumar K. V on 9 Aug 2010 11:00
On Sun, 8 Aug 2010 12:04:04 -0400, "Ted Ts'o" <tytso(a)mit.edu> wrote: > Stupid nit-pick in the subject line/patch summary: > > s;/proc/<pid>mountinfo;/proc/<pid>/mountinfo; > I updated the git repo to fix the commit message. I also rebased to the latest linus tree fixing some conflicts due to MAY_CHDIR. Also fixed a wrong put_filep usage in do_handle_open. The updated repo at git://git.kernel.org/pub/scm/linux/kernel/git/kvaneesh/linux-open-handle.git open-by-handle -aneesh -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo(a)vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/ |