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? 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/
