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path: root/fs/namespace.c
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2005-11-07[PATCH] lindent fs/namespace.cRam Pai
Signed-off-by: Ram Pai <linuxram@us.ibm.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-07[PATCH] make /proc/mounts pollableAl Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-07[PATCH] cleanups and bug fix in do_loopback()Al Viro
- check_mnt() on the source of binding should've been unconditional from the very beginning. My fault - as far I could've trace it, that's an old thinko made back in 2001. Kudos to Miklos for spotting it... Fixed. - code cleaned up. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-07[PATCH] saner handling of auto_acct_off() and DQUOT_OFF() in umountAl Viro
The way we currently deal with quota and process accounting that might keep vfsmount busy at umount time is inherently broken; we try to turn them off just in case (not quite correctly, at that) and a) pray umount doesn't fail (otherwise they'll stay turned off) b) pray nobody doesn anything funny just as we turn quota off Moreover, LSM provides hooks for doing the same sort of broken logics. The proper way to deal with that is to introduce the second kind of reference to vfsmount. Semantics: - when the last normal reference is dropped, all special ones are converted to normal ones and if there had been any, cleanup is done. - normal reference can be cloned into a special one - special reference can be converted to normal one; that's a no-op if we'd already passed the point of no return (i.e. mntput() had converted special references to normal and started cleanup). The way it works: e.g. starting process accounting converts the vfsmount reference pinned by the opened file into special one and turns it back to normal when it gets shut down; acct_auto_close() is done when no normal references are left. That way it does *not* obstruct umount(2) and it silently gets turned off when the last normal reference to vfsmount is gone. Which is exactly what we want... The same should be done by LSM module that holds some internal references to vfsmount and wants to shut them down on umount - it should make them special and security_sb_umount_close() will be called exactly when the last normal reference to vfsmount is gone. quota handling is even simpler - we don't use normal file IO anymore, so there's no need to hold vfsmounts at all. DQUOT_OFF() is done from deactivate_super(), where it really belongs. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-10[PATCH] janitor: fs/namespace.c: list_for_each_entryDomen Puncer
Make code more readable with list_for_each_entry. Signed-off-by: Maximilian Attems <janitor@sternwelten.at> Signed-off-by: Domen Puncer <domen@coderock.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-07[PATCH] pivot_root() circular reference fixMiklos Szeredi
Fix http://bugzilla.kernel.org/show_bug.cgi?id=4857 When pivot_root is called from an init script in an initramfs environment, it causes a circular reference in the mount tree. The cause of this is that pivot_root() is not prepared to handle pivoting an unattached mount. In an initramfs environment, rootfs is the root of the namespace, and so it is not attached. This patch fixes this and related problems, by returning -EINVAL if either the current root or the new root is detached. Signed-off-by: Miklos Szeredi <miklos@szeredi.hu> Acked-by: Al Viro <viro@parcelfarce.linux.theplanet.co.uk> Cc: <bigfish@asmallpond.org> Cc: Christoph Hellwig <hch@lst.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-07[PATCH] Additions to .data.read_mostly sectionRavikiran G Thirumalai
Mark variables which are usually accessed for reads with __readmostly. Signed-off-by: Alok N Kataria <alokk@calsoftinc.com> Signed-off-by: Shai Fultheim <shai@scalex86.org> Signed-off-by: Ravikiran Thirumalai <kiran@scalex86.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-08-07[PATCH] namespace.c: fix bind mount from foreign namespaceMiklos Szeredi
I'm resending this patch, because I still believe it's the correct fix. Tested before/after applying the patch with a test application available from: http://www.inf.bme.hu/~mszeredi/nstest.c Bind mount from a foreign namespace results in an un-removable mount. The reason is that mnt->mnt_namespace is copied from the old mount in clone_mnt(). Because of this check_mnt() in sys_umount() will fail. The solution is to set mnt->mnt_namespace to current->namespace in clone_mnt(). clone_mnt() is either called from do_loopback() or copy_tree(). copy_tree() is called from do_loopback() or copy_namespace(). When called (directly or indirectly) from do_loopback(), always current->namspace is being modified: check_mnt(nd->mnt). So setting mnt->mnt_namespace to current->namspace is the right thing to do. When called from copy_namespace(), the setting of mnt_namespace is irrelevant, since mnt_namespace is reset later in that function for all copied mounts. Jamie said: This patch is correct. The old code was buggy for more fundamental and serious reason: it broke the invariant that a tree of vfsmnts all have the same value of mnt_namespace (and the same for the mnt_list list). Signed-off-by: Miklos Szeredi <miklos@szeredi.hu> Acked-by: Jamie Lokier <jamie@shareable.org> Cc: <viro@parcelfarce.linux.theplanet.co.uk> Cc: Christoph Hellwig <hch@lst.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-07-07[PATCH] namespace: rename mnt_fslink to mnt_expireMiklos Szeredi
This patch renames vfsmount->mnt_fslink to something a little more descriptive: vfsmount->mnt_expire. Signed-off-by: Mike Waychison <michael.waychison@sun.com> Signed-off-by: Miklos Szeredi <miklos@szeredi.hu> Acked-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-07-07[PATCH] set mnt_namespace in the correct placeMiklos Szeredi
This patch sets ->mnt_namespace where it's actually added to the namespace. Previously mnt_namespace was set in do_kern_mount() even if the filesystem was never added to any process's namespace (most kernel-internal filesystems). This discrepancy doesn't actually cause any problems, but it's cleaner if mnt_namespace is NULL for these non exported filesystems. Signed-off-by: Miklos Szeredi <miklos@szeredi.hu> Acked-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-07-07[PATCH] namespace.c: fix mnt_namespace zeroing for expired mountsMiklos Szeredi
This patch clears mnt_namespace in an expired mount. If mnt_namespace is not cleared, it's possible to attach a new mount to the already detached mount, because check_mnt() can return true. The effect is a resource leak, since the resulting tree will never be freed. Signed-off-by: Miklos Szeredi <miklos@szeredi.hu> Acked-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-07-07[PATCH] namespace.c: fix expiring of detached mountMiklos Szeredi
This patch fixes a bug noticed by Al Viro: However, we still have a problem here - just what would happen if vfsmount is detached while we were grabbing namespace semaphore? Refcount alone is not useful here - we might be held by whoever had detached the vfsmount. IOW, we should check that it's still attached (i.e. that mnt->mnt_parent != mnt). If it's not - just leave it alone, do mntput() and let whoever holds it deal with the sucker. No need to put it back on lists. Signed-off-by: Miklos Szeredi <miklos@szeredi.hu> Cc: <viro@parcelfarce.linux.theplanet.co.uk> Acked-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-07-07[PATCH] namespace.c: split mark_mounts_for_expiry()Miklos Szeredi
This patch splits the mark_mounts_for_expiry() function. It's too complex and too deeply nested, even without the bugfix in the following patch. Otherwise code is completely the same. Signed-off-by: Miklos Szeredi <miklos@szeredi.hu> Cc: <viro@parcelfarce.linux.theplanet.co.uk> Acked-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-07-07[PATCH] namespace.c: cleanup in mark_mounts_for_expiry()Miklos Szeredi
This patch simplifies mark_mounts_for_expiry() by using detach_mnt() instead of duplicating everything it does. It should be an equivalent transformation except for righting the dput/mntput order. Al Viro said: "Looks sane". Signed-off-by: Miklos Szeredi <miklos@szeredi.hu> Cc: <viro@parcelfarce.linux.theplanet.co.uk> Acked-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-07-07[PATCH] namespace.c: fix race in mark_mounts_for_expiry()Miklos Szeredi
This patch fixes a race found by Ram in mark_mounts_for_expiry() in fs/namespace.c. The bug can only be triggered with simultaneous exiting of a process having a private namespace, and expiry of a mount from within that namespace. It's practically impossible to trigger, and I haven't even tried. But still, a bug is a bug. The race happens when put_namespace() is called by another task, while mark_mounts_for_expiry() is between atomic_read() and get_namespace(). In that case get_namespace() will be called on an already dead namespace with unforeseeable results. The solution was suggested by Al Viro, with his own words: Instead of screwing with atomic_read() in there, why don't we simply do the following: a) atomic_dec_and_lock() in put_namespace() b) __put_namespace() called without dropping lock c) the first thing done by __put_namespace would be struct vfsmount *root = namespace->root; namespace->root = NULL; spin_unlock(...); .... umount_tree(root); ... d) check in mark_... would be simply namespace && namespace->root. And we are all set; no screwing around with atomic_read(), no magic at all. Dying namespace gets NULL ->root. All changes of ->root happen under spinlock. If under a spinlock we see non-NULL ->mnt_namespace, it won't be freed until we drop the lock (we will set ->mnt_namespace to NULL under that lock before we get to freeing namespace). If under a spinlock we see non-NULL ->mnt_namespace and ->mnt_namespace->root, we can grab a reference to namespace and be sure that it won't go away. Signed-off-by: Miklos Szeredi <miklos@szeredi.hu> Acked-by: Al Viro <viro@parcelfarce.linux.theplanet.co.uk> Acked-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-07-07[PATCH] namespace.c: fix mnt_namespace clearingMiklos Szeredi
This patch clears mnt_namespace on unmount. Not clearing mnt_namespace has two effects: 1) It is possible to attach a new mount to a detached mount, because check_mnt() returns true. This means, that when no other references to the detached mount remain, it still can't be freed. This causes a resource leak, and possibly un-removable modules. 2) If mnt_namespace is dereferenced (only in mark_mounts_for_expiry()) after the namspace has been freed, it can cause an Oops, memory corruption, etc. 1) has been tested before and after the patch, 2) is only speculation. Signed-off-by: Miklos Szeredi <miklos@szeredi.hu> Acked-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-24[PATCH] make various thing staticAdrian Bunk
Another rollup of patches which give various symbols static scope Signed-off-by: Adrian Bunk <bunk@stusta.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-04-16Linux-2.6.12-rc2Linus Torvalds
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!