Andrew Morton wrote: > On Thu, 06 Dec 2007 09:21:53 +0100 Giacomo Catenazzi <[EMAIL PROTECTED]> > wrote: > >> Andrew Morton wrote: >>> On Mon, 3 Dec 2007 19:00:25 GMT Linux Kernel Mailing List >>> <linux-kernel@vger.kernel.org> wrote: >>> >>>> Gitweb: >>>> http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=2b1e300a9dfc3196ccddf6f1d74b91b7af55e416 >>>> Commit: 2b1e300a9dfc3196ccddf6f1d74b91b7af55e416 >>>> Parent: e03ba84adb62fbc6049325a5bc00ef6932fa5e39 >>>> Author: Eric W. Biederman <[EMAIL PROTECTED]> >>>> AuthorDate: Sun Dec 2 00:33:17 2007 +1100 >>>> Committer: Herbert Xu <[EMAIL PROTECTED]> >>>> CommitDate: Sun Dec 2 00:33:17 2007 +1100 >>>> >>>> [NETNS]: Fix /proc/net breakage >>>> >>>> Well I clearly goofed when I added the initial network namespace >>>> support >>>> for /proc/net. Currently things work but there are odd details >>>> visible to >>>> user space, even when we have a single network namespace. >>>> >>>> Since we do not cache proc_dir_entry dentries at the moment we can just >>>> modify ->lookup to return a different directory inode depending on the >>>> network namespace of the process looking at /proc/net, replacing the >>>> current technique of using a magic and fragile follow_link method. >>>> >>>> To accomplish that this patch: >>>> - introduces a shadow_proc method to allow different dentries to >>>> be returned from proc_lookup. >>>> - Removes the old /proc/net follow_link magic >>>> - Fixes a weakness in our not caching of proc generic dentries. >>>> >>>> As shadow_proc uses a task struct to decided which dentry to return we >>>> can >>>> go back later and fix the proc generic caching without modifying any >>>> code >>>> that uses the shadow_proc method. >>> This patch caused the binfmt_misc regression reported in >>> http://bugzilla.kernel.org/show_bug.cgi?id=9504 >> This patch also doesn't allow to mount /proc/bus/usb >> > > Does Denis's patch fix it?
Yes, this patch solve the problem. Tested-by: Giacomo Catenazzi <[EMAIL PROTECTED]> ciao cate > > Thanks. > > > From: "Denis V. Lunev" <[EMAIL PROTECTED]> > > /proc/sys/fs/binfmt_misc dentry disappeared during d_revalidate. > d_revalidate only dentries from shadowed one and below. > http://bugzilla.kernel.org/show_bug.cgi?id=9504 > > Cc: Eric W. Biederman <[EMAIL PROTECTED]> > Cc: Marcus Better <[EMAIL PROTECTED]> > Signed-off-by: Denis V. Lunev <[EMAIL PROTECTED]> > Cc: Marcus Better <[EMAIL PROTECTED]> > Signed-off-by: Andrew Morton <[EMAIL PROTECTED]> > --- > > fs/proc/generic.c | 14 ++++++++++++-- > 1 file changed, 12 insertions(+), 2 deletions(-) > > diff -puN fs/proc/generic.c~lost-content-of-proc-sys-fs-binfmt_misc > fs/proc/generic.c > --- a/fs/proc/generic.c~lost-content-of-proc-sys-fs-binfmt_misc > +++ a/fs/proc/generic.c > @@ -380,12 +380,17 @@ static int proc_revalidate_dentry(struct > return 0; > } > > -static struct dentry_operations proc_dentry_operations = > +static struct dentry_operations proc_dentry_shadow_operations = > { > .d_delete = proc_delete_dentry, > .d_revalidate = proc_revalidate_dentry, > }; > > +static struct dentry_operations proc_dentry_operations = > +{ > + .d_delete = proc_delete_dentry, > +}; > + > /* > * Don't create negative dentries here, return -ENOENT by hand > * instead. > @@ -394,6 +399,7 @@ struct dentry *proc_lookup(struct inode > { > struct inode *inode = NULL; > struct proc_dir_entry * de; > + int use_shadow = 0; > int error = -ENOENT; > > lock_kernel(); > @@ -406,8 +412,10 @@ struct dentry *proc_lookup(struct inode > if (!memcmp(dentry->d_name.name, de->name, > de->namelen)) { > unsigned int ino; > > - if (de->shadow_proc) > + if (de->shadow_proc) { > de = de->shadow_proc(current, de); > + use_shadow = 1; > + } > ino = de->low_ino; > de_get(de); > spin_unlock(&proc_subdir_lock); > @@ -423,6 +431,8 @@ struct dentry *proc_lookup(struct inode > > if (inode) { > dentry->d_op = &proc_dentry_operations; > + dentry->d_op = use_shadow ? > + &proc_dentry_shadow_operations : dentry->d_parent->d_op; > d_add(dentry, inode); > return NULL; > } > _ > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/