kernel/linux.git/fs/proc/generic.c, branch linux-6.0.y

proc: fix dentry/inode overinstantiating under /proc/${pid}/net

2022-05-10T01:29:19+00:00

When a process exits, /proc/${pid}, and /proc/${pid}/net dentries are flushed. However some leaf dentries like /proc/${pid}/net/arp_cache aren't. That's because respective PDEs have proc_misc_d_revalidate() hook which returns 1 and leaves dentries/inodes in the LRU. Force revalidation/lookup on everything under /proc/${pid}/net by inheriting proc_net_dentry_ops. [akpm@linux-foundation.org: coding-style cleanups] Link: https://lkml.kernel.org/r/YjdVHgildbWO7diJ@localhost.localdomain Fixes: c6c75deda813 ("proc: fix lookup in /proc/net subdirectories after setns(2)") Signed-off-by: Alexey Dobriyan Reported-by: hui li Cc: Al Viro Signed-off-by: Andrew Morton

fs: proc: store PDE()->data into inode->i_private

2022-01-22T06:33:37+00:00

PDE_DATA(inode) is introduced to get user private data and hide the layout of struct proc_dir_entry. The inode->i_private is used to do the same thing as well. Save a copy of user private data to inode-> i_private when proc inode is allocated. This means the user also can get their private data by inode->i_private. Introduce pde_data() to wrap inode->i_private so that we can remove PDE_DATA() from fs/proc/generic.c and make PTE_DATE() as a wrapper of pde_data(). It will be easier if we decide to remove PDE_DATE() in the future. Link: https://lkml.kernel.org/r/20211124081956.87711-1-songmuchun@bytedance.com Signed-off-by: Muchun Song Acked-by: Christian Brauner Cc: Alexey Dobriyan Cc: Alexey Gladkov Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

proc: save LOC in __xlate_proc_name()

2021-05-07T02:24:11+00:00

Can't look at this verbosity anymore. Link: https://lkml.kernel.org/r/YFYXAp/fgq405qcy@localhost.localdomain Signed-off-by: Alexey Dobriyan Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

fs/proc/generic.c: fix incorrect pde_is_permanent check

2021-05-07T02:24:11+00:00

Currently the pde_is_permanent() check is being run on root multiple times rather than on the next proc directory entry. This looks like a copy-paste error. Fix this by replacing root with next. Addresses-Coverity: ("Copy-paste error") Link: https://lkml.kernel.org/r/20210318122633.14222-1-colin.king@canonical.com Fixes: d919b33dafb3 ("proc: faster open/read/close with "permanent" files") Signed-off-by: Colin Ian King Acked-by: Christian Brauner Reviewed-by: Alexey Dobriyan Cc: Greg Kroah-Hartman Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

fs: make helpers idmap mount aware

2021-01-24T13:27:20+00:00

Extend some inode methods with an additional user namespace argument. A filesystem that is aware of idmapped mounts will receive the user namespace the mount has been marked with. This can be used for additional permission checking and also to enable filesystems to translate between uids and gids if they need to. We have implemented all relevant helpers in earlier patches. As requested we simply extend the exisiting inode method instead of introducing new ones. This is a little more code churn but it's mostly mechanical and doesnt't leave us with additional inode methods. Link: https://lore.kernel.org/r/20210121131959.646623-25-christian.brauner@ubuntu.com Cc: Christoph Hellwig Cc: David Howells Cc: Al Viro Cc: linux-fsdevel@vger.kernel.org Reviewed-by: Christoph Hellwig Signed-off-by: Christian Brauner

stat: handle idmapped mounts

2021-01-24T13:27:17+00:00

The generic_fillattr() helper fills in the basic attributes associated with an inode. Enable it to handle idmapped mounts. If the inode is accessed through an idmapped mount map it into the mount's user namespace before we store the uid and gid. If the initial user namespace is passed nothing changes so non-idmapped mounts will see identical behavior as before. Link: https://lore.kernel.org/r/20210121131959.646623-12-christian.brauner@ubuntu.com Cc: Christoph Hellwig Cc: David Howells Cc: Al Viro Cc: linux-fsdevel@vger.kernel.org Reviewed-by: Christoph Hellwig Reviewed-by: James Morris Signed-off-by: Christian Brauner

attr: handle idmapped mounts

2021-01-24T13:27:16+00:00

When file attributes are changed most filesystems rely on the setattr_prepare(), setattr_copy(), and notify_change() helpers for initialization and permission checking. Let them handle idmapped mounts. If the inode is accessed through an idmapped mount map it into the mount's user namespace. Afterwards the checks are identical to non-idmapped mounts. If the initial user namespace is passed nothing changes so non-idmapped mounts will see identical behavior as before. Helpers that perform checks on the ia_uid and ia_gid fields in struct iattr assume that ia_uid and ia_gid are intended values and have already been mapped correctly at the userspace-kernelspace boundary as we already do today. If the initial user namespace is passed nothing changes so non-idmapped mounts will see identical behavior as before. Link: https://lore.kernel.org/r/20210121131959.646623-8-christian.brauner@ubuntu.com Cc: Christoph Hellwig Cc: David Howells Cc: Al Viro Cc: linux-fsdevel@vger.kernel.org Reviewed-by: Christoph Hellwig Signed-off-by: Christian Brauner

proc: fix lookup in /proc/net subdirectories after setns(2)

2020-12-16T06:46:15+00:00

Commit 1fde6f21d90f ("proc: fix /proc/net/* after setns(2)") only forced revalidation of regular files under /proc/net/ However, /proc/net/ is unusual in the sense of /proc/net/foo handlers take netns pointer from parent directory which is old netns. Steps to reproduce: (void)open("/proc/net/sctp/snmp", O_RDONLY); unshare(CLONE_NEWNET); int fd = open("/proc/net/sctp/snmp", O_RDONLY); read(fd, &c, 1); Read will read wrong data from original netns. Patch forces lookup on every directory under /proc/net . Link: https://lkml.kernel.org/r/20201205160916.GA109739@localhost.localdomain Fixes: 1da4d377f943 ("proc: revalidate misc dentries") Signed-off-by: Alexey Dobriyan Reported-by: "Rantala, Tommi T. (Nokia - FI/Espoo)" Cc: Al Viro Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

proc "seq files": switch to ->read_iter

2020-11-06T18:05:18+00:00

Implement ->read_iter for all proc "seq files" so that splice works on them. Suggested-by: Linus Torvalds Signed-off-by: Christoph Hellwig Signed-off-by: Linus Torvalds

proc "single files": switch to ->read_iter

2020-11-06T18:05:18+00:00

Implement ->read_iter for all proc "single files" so that more bionic tests cases can pass when they call splice() on other fun files like /proc/version Signed-off-by: Greg Kroah-Hartman Signed-off-by: Christoph Hellwig Signed-off-by: Linus Torvalds