kernel/git/stable/linux-stable.git/fs/kernfs, branch linux-3.16.y

kernfs: fix regression in kernfs_fop_write caused by wrong type

2018-06-16T21:21:56+00:00

commit ba87977a49913129962af8ac35b0e13e0fa4382d upstream. Commit b7ce40cff0b9 ("kernfs: cache atomic_write_len in kernfs_open_file") changes type of local variable 'len' from ssize_t to size_t. This change caused that the *ppos value is updated also when the previous write callback failed. Mentioned snippet: ... len = ops->write(...); <- return value can be negative ... if (len > 0) <- true here in this case *ppos += len; ... Fixes: b7ce40cff0b9 ("kernfs: cache atomic_write_len in kernfs_open_file") Acked-by: Tejun Heo Signed-off-by: Ivan Vecera Signed-off-by: Al Viro Signed-off-by: Ben Hutchings

fs: Give dentry to inode_change_ok() instead of inode

2017-02-23T03:53:52+00:00

commit 31051c85b5e2aaaf6315f74c72a732673632a905 upstream. inode_change_ok() will be resposible for clearing capabilities and IMA extended attributes and as such will need dentry. Give it as an argument to inode_change_ok() instead of an inode. Also rename inode_change_ok() to setattr_prepare() to better relect that it does also some modifications in addition to checks. Reviewed-by: Christoph Hellwig Signed-off-by: Jan Kara [bwh: Backported to 3.16: - Drop changes to orangefs, overlayfs - Adjust filenames, context - In nfsd, pass dentry to nfsd_sanitize_attrs() - Update ext3 as well] Signed-off-by: Ben Hutchings

Revert "fs: Give dentry to inode_change_ok() instead of inode"

2017-02-23T03:53:52+00:00

This reverts commit be9df699432235753c3824b0f5a27d46de7fdc9e, which was commit 31051c85b5e2aaaf6315f74c72a732673632a905 upstream. The backport breaks fuse and makes a mess of xfs, which can be improved by picking further upstream commits as I should have done in the first place. Signed-off-by: Ben Hutchings

fs: Give dentry to inode_change_ok() instead of inode

2016-11-20T01:17:38+00:00

commit 31051c85b5e2aaaf6315f74c72a732673632a905 upstream. inode_change_ok() will be resposible for clearing capabilities and IMA extended attributes and as such will need dentry. Give it as an argument to inode_change_ok() instead of an inode. Also rename inode_change_ok() to setattr_prepare() to better relect that it does also some modifications in addition to checks. Reviewed-by: Christoph Hellwig Signed-off-by: Jan Kara [bwh: Backported to 3.16: - Drop changes to orangefs, overlayfs - Adjust filenames, context - In fuse, pass dentry to fuse_do_setattr() - In nfsd, pass dentry to nfsd_sanitize_attrs() - In xfs, pass dentry to xfs_setattr_nonsize() and xfs_setattr_size() - Update ext3 as well] Signed-off-by: Ben Hutchings

kernfs: don't depend on d_find_any_alias() when generating notifications

2016-11-20T01:17:20+00:00

commit df6a58c5c5aa8ecb1e088ecead3fa33ae70181f1 upstream. kernfs_notify_workfn() sends out file modified events for the scheduled kernfs_nodes. Because the modifications aren't from userland, it doesn't have the matching file struct at hand and can't use fsnotify_modify(). Instead, it looked up the inode and then used d_find_any_alias() to find the dentry and used fsnotify_parent() and fsnotify() directly to generate notifications. The assumption was that the relevant dentries would have been pinned if there are listeners, which isn't true as inotify doesn't pin dentries at all and watching the parent doesn't pin the child dentries even for dnotify. This led to, for example, inotify watchers not getting notifications if the system is under memory pressure and the matching dentries got reclaimed. It can also be triggered through /proc/sys/vm/drop_caches or a remount attempt which involves shrinking dcache. fsnotify_parent() only uses the dentry to access the parent inode, which kernfs can do easily. Update kernfs_notify_workfn() so that it uses fsnotify() directly for both the parent and target inodes without going through d_find_any_alias(). While at it, supply the target file name to fsnotify() from kernfs_node->name. Signed-off-by: Tejun Heo Reported-by: Evgeny Vereshchagin Fixes: d911d9874801 ("kernfs: make kernfs_notify() trigger inotify events too") Cc: John McCutchan Cc: Robert Love Cc: Eric Paris Signed-off-by: Greg Kroah-Hartman Signed-off-by: Ben Hutchings

kernfs: Add support for always empty directories.

2015-07-15T09:01:07+00:00

commit ea015218f2f7ace2dad9cedd21ed95bdba2886d7 upstream. Add a new function kernfs_create_empty_dir that can be used to create directory that can not be modified. Update the code to use make_empty_dir_inode when reporting a permanently empty directory to the vfs. Update the code to not allow adding to permanently empty directories. Signed-off-by: "Eric W. Biederman" Signed-off-by: Luis Henriques

Merge branch 'for-3.16-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup

2014-07-10T18:38:23+00:00

Pull cgroup fixes from Tejun Heo: "Mostly fixes for the fallouts from the recent cgroup core changes. The decoupled nature of cgroup dynamic hierarchy management (hierarchies are created dynamically on mount but may or may not be reused once unmounted depending on remaining usages) led to more ugliness being added to kernfs. Hopefully, this is the last of it" * 'for-3.16-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup: cpuset: break kernfs active protection in cpuset_write_resmask() cgroup: fix a race between cgroup_mount() and cgroup_kill_sb() kernfs: introduce kernfs_pin_sb() cgroup: fix mount failure in a corner case cpuset,mempolicy: fix sleeping function called from invalid context cgroup: fix broken css_has_online_children()

kernfs: kernfs_notify() must be useable from non-sleepable contexts

2014-07-02T16:32:09+00:00

d911d9874801 ("kernfs: make kernfs_notify() trigger inotify events too") added fsnotify triggering to kernfs_notify() which requires a sleepable context. There are already existing users of kernfs_notify() which invoke it from an atomic context and in general it's silly to require a sleepable context for triggering a notification. The following is an invalid context bug triggerd by md invoking sysfs_notify() from IO completion path. BUG: sleeping function called from invalid context at kernel/locking/mutex.c:586 in_atomic(): 1, irqs_disabled(): 1, pid: 0, name: swapper/1 2 locks held by swapper/1/0: #0: (&(&vblk->vq_lock)->rlock){-.-...}, at: [] virtblk_done+0x42/0xe0 [virtio_blk] #1: (&(&bitmap->counts.lock)->rlock){-.....}, at: [] bitmap_endwrite+0x68/0x240 irq event stamp: 33518 hardirqs last enabled at (33515): [] default_idle+0x1f/0x230 hardirqs last disabled at (33516): [] common_interrupt+0x6d/0x72 softirqs last enabled at (33518): [] _local_bh_enable+0x22/0x50 softirqs last disabled at (33517): [] irq_enter+0x60/0x80 CPU: 1 PID: 0 Comm: swapper/1 Not tainted 3.16.0-0.rc2.git2.1.fc21.x86_64 #1 Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011 0000000000000000 f90db13964f4ee05 ffff88007d403b80 ffffffff81807b4c 0000000000000000 ffff88007d403ba8 ffffffff810d4f14 0000000000000000 0000000000441800 ffff880078fa1780 ffff88007d403c38 ffffffff8180caf2 Call Trace: [] dump_stack+0x4d/0x66 [] __might_sleep+0x184/0x240 [] mutex_lock_nested+0x42/0x440 [] kernfs_notify+0x90/0x150 [] bitmap_endwrite+0xcc/0x240 [] close_write+0x93/0xb0 [raid1] [] r1_bio_write_done+0x29/0x50 [raid1] [] raid1_end_write_request+0xe4/0x260 [raid1] [] bio_endio+0x6b/0xa0 [] blk_update_request+0x94/0x420 [] blk_mq_end_io+0x1a/0x70 [] virtblk_request_done+0x32/0x80 [virtio_blk] [] __blk_mq_complete_request+0x88/0x120 [] blk_mq_complete_request+0x2a/0x30 [] virtblk_done+0x66/0xe0 [virtio_blk] [] vring_interrupt+0x3a/0xa0 [virtio_ring] [] handle_irq_event_percpu+0x77/0x340 [] handle_irq_event+0x3d/0x60 [] handle_edge_irq+0x66/0x130 [] handle_irq+0x84/0x150 [] do_IRQ+0x4d/0xe0 [] common_interrupt+0x72/0x72 [] ? native_safe_halt+0x6/0x10 [] default_idle+0x24/0x230 [] arch_cpu_idle+0xf/0x20 [] cpu_startup_entry+0x37c/0x7b0 [] start_secondary+0x25b/0x300 This patch fixes it by punting the notification delivery through a work item. This ends up adding an extra pointer to kernfs_elem_attr enlarging kernfs_node by a pointer, which is not ideal but not a very big deal either. If this turns out to be an actual issue, we can move kernfs_elem_attr->size to kernfs_node->iattr later. Signed-off-by: Tejun Heo Reported-by: Josh Boyer Cc: Jens Axboe Reviewed-by: Michael S. Tsirkin Signed-off-by: Greg Kroah-Hartman

kernfs: introduce kernfs_pin_sb()

2014-06-30T14:16:25+00:00

kernfs_pin_sb() tries to get a refcnt of the superblock. This will be used by cgroupfs. v2: - make kernfs_pin_sb() return the superblock. - drop kernfs_drop_sb(). tj: Updated the comment a bit. [ This is a prerequisite for a bugfix. ] Cc: # 3.15 Acked-by: Greg Kroah-Hartman Signed-off-by: Li Zefan Signed-off-by: Tejun Heo

kernfs: move the last knowledge of sysfs out from kernfs

2014-05-27T21:33:17+00:00

There is still one residue of sysfs remaining: the sb_magic SYSFS_MAGIC. However this should be kernfs user specific, so this patch moves it out. Kerrnfs user should specify their magic number while mouting. Signed-off-by: Jianyu Zhan Acked-by: Tejun Heo Signed-off-by: Greg Kroah-Hartman