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* switch ->setxattr() to passing dentry and inode separatelyAl Viro2016-05-282-6/+8
| | | | | | | | | | | | | | | | smack ->d_instantiate() uses ->setxattr(), so to be able to call it before we'd hashed the new dentry and attached it to inode, we need ->setxattr() instances getting the inode as an explicit argument rather than obtaining it from dentry. Similar change for ->getxattr() had been done in commit ce23e64. Unlike ->getxattr() (which is used by both selinux and smack instances of ->d_instantiate()) ->setxattr() is used only by smack one and unfortunately it got missed back then. Reported-by: Seung-Woo Kim <sw0312.kim@samsung.com> Tested-by: Casey Schaufler <casey@schaufler-ca.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* Merge tag 'driver-core-4.7-rc1' of ↵Linus Torvalds2016-05-213-30/+44
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core Pull driver core updates from Greg KH: "Here's the "big" driver core update for 4.7-rc1. Mostly just debugfs changes, the long-known and messy races with removing debugfs files should be fixed thanks to the great work of Nicolai Stange. We also have some isa updates in here (the x86 maintainers told me to take it through this tree), a new warning when we run out of dynamic char major numbers, and a few other assorted changes, details in the shortlog. All have been in linux-next for some time with no reported issues" * tag 'driver-core-4.7-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (32 commits) Revert "base: dd: don't remove driver_data in -EPROBE_DEFER case" gpio: ws16c48: Utilize the ISA bus driver gpio: 104-idio-16: Utilize the ISA bus driver gpio: 104-idi-48: Utilize the ISA bus driver gpio: 104-dio-48e: Utilize the ISA bus driver watchdog: ebc-c384_wdt: Utilize the ISA bus driver iio: stx104: Utilize the module_isa_driver and max_num_isa_dev macros iio: stx104: Add X86 dependency to STX104 Kconfig option Documentation: Add ISA bus driver documentation isa: Implement the max_num_isa_dev macro isa: Implement the module_isa_driver macro pnp: pnpbios: Add explicit X86_32 dependency to PNPBIOS isa: Decouple X86_32 dependency from the ISA Kconfig option driver-core: use 'dev' argument in dev_dbg_ratelimited stub base: dd: don't remove driver_data in -EPROBE_DEFER case kernfs: Move faulting copy_user operations outside of the mutex devcoredump: add scatterlist support debugfs: unproxify files created through debugfs_create_u32_array() debugfs: unproxify files created through debugfs_create_blob() debugfs: unproxify files created through debugfs_create_bool() ...
| * kernfs: Move faulting copy_user operations outside of the mutexChris Wilson2016-04-301-22/+29
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | A fault in a user provided buffer may lead anywhere, and lockdep warns that we have a potential deadlock between the mm->mmap_sem and the kernfs file mutex: [ 82.811702] ====================================================== [ 82.811705] [ INFO: possible circular locking dependency detected ] [ 82.811709] 4.5.0-rc4-gfxbench+ #1 Not tainted [ 82.811711] ------------------------------------------------------- [ 82.811714] kms_setmode/5859 is trying to acquire lock: [ 82.811717] (&dev->struct_mutex){+.+.+.}, at: [<ffffffff8150d9c1>] drm_gem_mmap+0x1a1/0x270 [ 82.811731] but task is already holding lock: [ 82.811734] (&mm->mmap_sem){++++++}, at: [<ffffffff8117b364>] vm_mmap_pgoff+0x44/0xa0 [ 82.811745] which lock already depends on the new lock. [ 82.811749] the existing dependency chain (in reverse order) is: [ 82.811752] -> #3 (&mm->mmap_sem){++++++}: [ 82.811761] [<ffffffff810cc883>] lock_acquire+0xc3/0x1d0 [ 82.811766] [<ffffffff8118bc65>] __might_fault+0x75/0xa0 [ 82.811771] [<ffffffff8124da4a>] kernfs_fop_write+0x8a/0x180 [ 82.811787] [<ffffffff811d1023>] __vfs_write+0x23/0xe0 [ 82.811792] [<ffffffff811d1d74>] vfs_write+0xa4/0x190 [ 82.811797] [<ffffffff811d2c14>] SyS_write+0x44/0xb0 [ 82.811801] [<ffffffff817bb81b>] entry_SYSCALL_64_fastpath+0x16/0x73 [ 82.811807] -> #2 (s_active#6){++++.+}: [ 82.811814] [<ffffffff810cc883>] lock_acquire+0xc3/0x1d0 [ 82.811819] [<ffffffff8124c070>] __kernfs_remove+0x210/0x2f0 [ 82.811823] [<ffffffff8124d040>] kernfs_remove_by_name_ns+0x40/0xa0 [ 82.811828] [<ffffffff8124e9e0>] sysfs_remove_file_ns+0x10/0x20 [ 82.811832] [<ffffffff815318d4>] device_del+0x124/0x250 [ 82.811837] [<ffffffff81531a19>] device_unregister+0x19/0x60 [ 82.811841] [<ffffffff8153c051>] cpu_cache_sysfs_exit+0x51/0xb0 [ 82.811846] [<ffffffff8153c628>] cacheinfo_cpu_callback+0x38/0x70 [ 82.811851] [<ffffffff8109ae89>] notifier_call_chain+0x39/0xa0 [ 82.811856] [<ffffffff8109aef9>] __raw_notifier_call_chain+0x9/0x10 [ 82.811860] [<ffffffff810786de>] cpu_notify+0x1e/0x40 [ 82.811865] [<ffffffff81078779>] cpu_notify_nofail+0x9/0x20 [ 82.811869] [<ffffffff81078ac3>] _cpu_down+0x233/0x340 [ 82.811874] [<ffffffff81079019>] disable_nonboot_cpus+0xc9/0x350 [ 82.811878] [<ffffffff810d2e11>] suspend_devices_and_enter+0x5a1/0xb50 [ 82.811883] [<ffffffff810d3903>] pm_suspend+0x543/0x8d0 [ 82.811888] [<ffffffff810d1b77>] state_store+0x77/0xe0 [ 82.811892] [<ffffffff813fa68f>] kobj_attr_store+0xf/0x20 [ 82.811897] [<ffffffff8124e740>] sysfs_kf_write+0x40/0x50 [ 82.811902] [<ffffffff8124dafc>] kernfs_fop_write+0x13c/0x180 [ 82.811906] [<ffffffff811d1023>] __vfs_write+0x23/0xe0 [ 82.811910] [<ffffffff811d1d74>] vfs_write+0xa4/0x190 [ 82.811914] [<ffffffff811d2c14>] SyS_write+0x44/0xb0 [ 82.811918] [<ffffffff817bb81b>] entry_SYSCALL_64_fastpath+0x16/0x73 [ 82.811923] -> #1 (cpu_hotplug.lock){+.+.+.}: [ 82.811929] [<ffffffff810cc883>] lock_acquire+0xc3/0x1d0 [ 82.811933] [<ffffffff817b6f72>] mutex_lock_nested+0x62/0x3b0 [ 82.811940] [<ffffffff810784c1>] get_online_cpus+0x61/0x80 [ 82.811944] [<ffffffff811170eb>] stop_machine+0x1b/0xe0 [ 82.811949] [<ffffffffa0178edd>] gen8_ggtt_insert_entries__BKL+0x2d/0x30 [i915] [ 82.812009] [<ffffffffa017d3a6>] ggtt_bind_vma+0x46/0x70 [i915] [ 82.812045] [<ffffffffa017eb70>] i915_vma_bind+0x140/0x290 [i915] [ 82.812081] [<ffffffffa01862b9>] i915_gem_object_do_pin+0x899/0xb00 [i915] [ 82.812117] [<ffffffffa0186555>] i915_gem_object_pin+0x35/0x40 [i915] [ 82.812154] [<ffffffffa019a23e>] intel_init_pipe_control+0xbe/0x210 [i915] [ 82.812192] [<ffffffffa0197312>] intel_logical_rings_init+0xe2/0xde0 [i915] [ 82.812232] [<ffffffffa0186fe3>] i915_gem_init+0xf3/0x130 [i915] [ 82.812278] [<ffffffffa02097ed>] i915_driver_load+0xf2d/0x1770 [i915] [ 82.812318] [<ffffffff81512474>] drm_dev_register+0xa4/0xb0 [ 82.812323] [<ffffffff8151467e>] drm_get_pci_dev+0xce/0x1e0 [ 82.812328] [<ffffffffa01472cf>] i915_pci_probe+0x2f/0x50 [i915] [ 82.812360] [<ffffffff8143f907>] pci_device_probe+0x87/0xf0 [ 82.812366] [<ffffffff81535f89>] driver_probe_device+0x229/0x450 [ 82.812371] [<ffffffff81536233>] __driver_attach+0x83/0x90 [ 82.812375] [<ffffffff81533c61>] bus_for_each_dev+0x61/0xa0 [ 82.812380] [<ffffffff81535879>] driver_attach+0x19/0x20 [ 82.812384] [<ffffffff8153535f>] bus_add_driver+0x1ef/0x290 [ 82.812388] [<ffffffff81536e9b>] driver_register+0x5b/0xe0 [ 82.812393] [<ffffffff8143e83b>] __pci_register_driver+0x5b/0x60 [ 82.812398] [<ffffffff81514866>] drm_pci_init+0xd6/0x100 [ 82.812402] [<ffffffffa027c094>] 0xffffffffa027c094 [ 82.812406] [<ffffffff810003de>] do_one_initcall+0xae/0x1d0 [ 82.812412] [<ffffffff811595a0>] do_init_module+0x5b/0x1cb [ 82.812417] [<ffffffff81106160>] load_module+0x1c20/0x2480 [ 82.812422] [<ffffffff81106bae>] SyS_finit_module+0x7e/0xa0 [ 82.812428] [<ffffffff817bb81b>] entry_SYSCALL_64_fastpath+0x16/0x73 [ 82.812433] -> #0 (&dev->struct_mutex){+.+.+.}: [ 82.812439] [<ffffffff810cbe59>] __lock_acquire+0x1fc9/0x20f0 [ 82.812443] [<ffffffff810cc883>] lock_acquire+0xc3/0x1d0 [ 82.812456] [<ffffffff8150d9e7>] drm_gem_mmap+0x1c7/0x270 [ 82.812460] [<ffffffff81196a14>] mmap_region+0x334/0x580 [ 82.812466] [<ffffffff81196fc4>] do_mmap+0x364/0x410 [ 82.812470] [<ffffffff8117b38d>] vm_mmap_pgoff+0x6d/0xa0 [ 82.812474] [<ffffffff811950f4>] SyS_mmap_pgoff+0x184/0x220 [ 82.812479] [<ffffffff8100a0fd>] SyS_mmap+0x1d/0x20 [ 82.812484] [<ffffffff817bb81b>] entry_SYSCALL_64_fastpath+0x16/0x73 [ 82.812489] other info that might help us debug this: [ 82.812493] Chain exists of: &dev->struct_mutex --> s_active#6 --> &mm->mmap_sem [ 82.812502] Possible unsafe locking scenario: [ 82.812506] CPU0 CPU1 [ 82.812508] ---- ---- [ 82.812510] lock(&mm->mmap_sem); [ 82.812514] lock(s_active#6); [ 82.812519] lock(&mm->mmap_sem); [ 82.812522] lock(&dev->struct_mutex); [ 82.812526] *** DEADLOCK *** [ 82.812531] 1 lock held by kms_setmode/5859: [ 82.812533] #0: (&mm->mmap_sem){++++++}, at: [<ffffffff8117b364>] vm_mmap_pgoff+0x44/0xa0 [ 82.812541] stack backtrace: [ 82.812547] CPU: 0 PID: 5859 Comm: kms_setmode Not tainted 4.5.0-rc4-gfxbench+ #1 [ 82.812550] Hardware name: /NUC5CPYB, BIOS PYBSWCEL.86A.0040.2015.0814.1353 08/14/2015 [ 82.812553] 0000000000000000 ffff880079407bf0 ffffffff813f8505 ffffffff825fb270 [ 82.812560] ffffffff825c4190 ffff880079407c30 ffffffff810c84ac ffff880079407c90 [ 82.812566] ffff8800797ed328 ffff8800797ecb00 0000000000000001 ffff8800797ed350 [ 82.812573] Call Trace: [ 82.812578] [<ffffffff813f8505>] dump_stack+0x67/0x92 [ 82.812582] [<ffffffff810c84ac>] print_circular_bug+0x1fc/0x310 [ 82.812586] [<ffffffff810cbe59>] __lock_acquire+0x1fc9/0x20f0 [ 82.812590] [<ffffffff810cc883>] lock_acquire+0xc3/0x1d0 [ 82.812594] [<ffffffff8150d9c1>] ? drm_gem_mmap+0x1a1/0x270 [ 82.812599] [<ffffffff8150d9e7>] drm_gem_mmap+0x1c7/0x270 [ 82.812603] [<ffffffff8150d9c1>] ? drm_gem_mmap+0x1a1/0x270 [ 82.812608] [<ffffffff81196a14>] mmap_region+0x334/0x580 [ 82.812612] [<ffffffff81196fc4>] do_mmap+0x364/0x410 [ 82.812616] [<ffffffff8117b38d>] vm_mmap_pgoff+0x6d/0xa0 [ 82.812629] [<ffffffff811950f4>] SyS_mmap_pgoff+0x184/0x220 [ 82.812633] [<ffffffff8100a0fd>] SyS_mmap+0x1d/0x20 [ 82.812637] [<ffffffff817bb81b>] entry_SYSCALL_64_fastpath+0x16/0x73 Highly unlikely though this scenario is, we can avoid the issue entirely by moving the copy operation from out under the kernfs_get_active() tracking by assigning the preallocated buffer its own mutex. The temporary buffer allocation doesn't require mutex locking as it is entirely local. The locked section was extended by the addition of the preallocated buf to speed up md user operations in commit 2b75869bba676c248d8d25ae6d2bd9221dfffdb6 Author: NeilBrown <neilb@suse.de> Date: Mon Oct 13 16:41:28 2014 +1100 sysfs/kernfs: allow attributes to request write buffer be pre-allocated. Reported-by: Ville Syrjälä <ville.syrjala@linux.intel.com> Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=94350 Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com> Cc: Ville Syrjälä <ville.syrjala@linux.intel.com> Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com> Cc: NeilBrown <neilb@suse.de> Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * Merge 4.6-rc4 into driver-core-nextGreg Kroah-Hartman2016-04-181-2/+2
| |\ | | | | | | | | | | | | | | | We want those fixes in here as well. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * | fs: kernfs: Replace CURRENT_TIME by current_fs_time()Deepa Dinamani2016-03-292-8/+15
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This is in preparation for the series that transitions filesystem timestamps to use 64 bit time and hence make them y2038 safe. CURRENT_TIME macro will be deleted before merging the aforementioned series. Use current_fs_time() instead of CURRENT_TIME for inode timestamps. struct kernfs_node is associated with a sysfs file/ directory. Truncate the values to appropriate time granularity when writing to inode timestamps of the files. ktime_get_real_ts() is used to obtain times for struct kernfs_iattrs. Since these times are later assigned to inode times using timespec_truncate() for all filesystem based operations, we can save the supers list traversal time here by using ktime_get_real_ts() directly. Signed-off-by: Deepa Dinamani <deepa.kernel@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* | | Merge branch 'for-linus' of ↵Linus Torvalds2016-05-174-23/+9
|\ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull parallel filesystem directory handling update from Al Viro. This is the main parallel directory work by Al that makes the vfs layer able to do lookup and readdir in parallel within a single directory. That's a big change, since this used to be all protected by the directory inode mutex. The inode mutex is replaced by an rwsem, and serialization of lookups of a single name is done by a "in-progress" dentry marker. The series begins with xattr cleanups, and then ends with switching filesystems over to actually doing the readdir in parallel (switching to the "iterate_shared()" that only takes the read lock). A more detailed explanation of the process from Al Viro: "The xattr work starts with some acl fixes, then switches ->getxattr to passing inode and dentry separately. This is the point where the things start to get tricky - that got merged into the very beginning of the -rc3-based #work.lookups, to allow untangling the security_d_instantiate() mess. The xattr work itself proceeds to switch a lot of filesystems to generic_...xattr(); no complications there. After that initial xattr work, the series then does the following: - untangle security_d_instantiate() - convert a bunch of open-coded lookup_one_len_unlocked() to calls of that thing; one such place (in overlayfs) actually yields a trivial conflict with overlayfs fixes later in the cycle - overlayfs ended up switching to a variant of lookup_one_len_unlocked() sans the permission checks. I would've dropped that commit (it gets overridden on merge from #ovl-fixes in #for-next; proper resolution is to use the variant in mainline fs/overlayfs/super.c), but I didn't want to rebase the damn thing - it was fairly late in the cycle... - some filesystems had managed to depend on lookup/lookup exclusion for *fs-internal* data structures in a way that would break if we relaxed the VFS exclusion. Fixing hadn't been hard, fortunately. - core of that series - parallel lookup machinery, replacing ->i_mutex with rwsem, making lookup_slow() take it only shared. At that point lookups happen in parallel; lookups on the same name wait for the in-progress one to be done with that dentry. Surprisingly little code, at that - almost all of it is in fs/dcache.c, with fs/namei.c changes limited to lookup_slow() - making it use the new primitive and actually switching to locking shared. - parallel readdir stuff - first of all, we provide the exclusion on per-struct file basis, same as we do for read() vs lseek() for regular files. That takes care of most of the needed exclusion in readdir/readdir; however, these guys are trickier than lookups, so I went for switching them one-by-one. To do that, a new method '->iterate_shared()' is added and filesystems are switched to it as they are either confirmed to be OK with shared lock on directory or fixed to be OK with that. I hope to kill the original method come next cycle (almost all in-tree filesystems are switched already), but it's still not quite finished. - several filesystems get switched to parallel readdir. The interesting part here is dealing with dcache preseeding by readdir; that needs minor adjustment to be safe with directory locked only shared. Most of the filesystems doing that got switched to in those commits. Important exception: NFS. Turns out that NFS folks, with their, er, insistence on VFS getting the fuck out of the way of the Smart Filesystem Code That Knows How And What To Lock(tm) have grown the locking of their own. They had their own homegrown rwsem, with lookup/readdir/atomic_open being *writers* (sillyunlink is the reader there). Of course, with VFS getting the fuck out of the way, as requested, the actual smarts of the smart filesystem code etc. had become exposed... - do_last/lookup_open/atomic_open cleanups. As the result, open() without O_CREAT locks the directory only shared. Including the ->atomic_open() case. Backmerge from #for-linus in the middle of that - atomic_open() fix got brought in. - then comes NFS switch to saner (VFS-based ;-) locking, killing the homegrown "lookup and readdir are writers" kinda-sorta rwsem. All exclusion for sillyunlink/lookup is done by the parallel lookups mechanism. Exclusion between sillyunlink and rmdir is a real rwsem now - rmdir being the writer. Result: NFS lookups/readdirs/O_CREAT-less opens happen in parallel now. - the rest of the series consists of switching a lot of filesystems to parallel readdir; in a lot of cases ->llseek() gets simplified as well. One backmerge in there (again, #for-linus - rockridge fix)" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (74 commits) ext4: switch to ->iterate_shared() hfs: switch to ->iterate_shared() hfsplus: switch to ->iterate_shared() hostfs: switch to ->iterate_shared() hpfs: switch to ->iterate_shared() hpfs: handle allocation failures in hpfs_add_pos() gfs2: switch to ->iterate_shared() f2fs: switch to ->iterate_shared() afs: switch to ->iterate_shared() befs: switch to ->iterate_shared() befs: constify stuff a bit isofs: switch to ->iterate_shared() get_acorn_filename(): deobfuscate a bit btrfs: switch to ->iterate_shared() logfs: no need to lock directory in lseek switch ecryptfs to ->iterate_shared 9p: switch to ->iterate_shared() fat: switch to ->iterate_shared() romfs, squashfs: switch to ->iterate_shared() more trivial ->iterate_shared conversions ...
| * | | kernfs: no point locking directory around that generic_file_llseek()Al Viro2016-05-091-15/+2
| | | | | | | | | | | | | | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * | | kernfs: use lookup_one_len_unlocked()Al Viro2016-05-031-3/+2
| | | | | | | | | | | | | | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * | | Merge getxattr prototype change into work.lookupsAl Viro2016-05-032-5/+5
| |\ \ \ | | |_|/ | |/| | | | | | The rest of work.xattr stuff isn't needed for this branch
| | * | ->getxattr(): pass dentry and inode as separate argumentsAl Viro2016-04-112-5/+5
| | |/ | | | | | | | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* | | kernfs: kernfs_sop_show_path: don't return 0 after seq_dentry callSerge E. Hallyn2016-05-121-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Our caller expects 0 on success, not >0. This fixes a bug in the patch cgroup, kernfs: make mountinfo show properly scoped path for cgroup namespaces where /sys does not show up in mountinfo, breaking criu. Thanks for catching this, Andrei. Reported-by: Andrei Vagin <avagin@gmail.com> Signed-off-by: Serge Hallyn <serge.hallyn@ubuntu.com> Signed-off-by: Tejun Heo <tj@kernel.org>
* | | cgroup, kernfs: make mountinfo show properly scoped path for cgroup namespacesSerge E. Hallyn2016-05-091-0/+14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Patch summary: When showing a cgroupfs entry in mountinfo, show the path of the mount root dentry relative to the reader's cgroup namespace root. Short explanation (courtesy of mkerrisk): If we create a new cgroup namespace, then we want both /proc/self/cgroup and /proc/self/mountinfo to show cgroup paths that are correctly virtualized with respect to the cgroup mount point. Previous to this patch, /proc/self/cgroup shows the right info, but /proc/self/mountinfo does not. Long version: When a uid 0 task which is in freezer cgroup /a/b, unshares a new cgroup namespace, and then mounts a new instance of the freezer cgroup, the new mount will be rooted at /a/b. The root dentry field of the mountinfo entry will show '/a/b'. cat > /tmp/do1 << EOF mount -t cgroup -o freezer freezer /mnt grep freezer /proc/self/mountinfo EOF unshare -Gm bash /tmp/do1 > 330 160 0:34 / /sys/fs/cgroup/freezer rw,nosuid,nodev,noexec,relatime - cgroup cgroup rw,freezer > 355 133 0:34 /a/b /mnt rw,relatime - cgroup freezer rw,freezer The task's freezer cgroup entry in /proc/self/cgroup will simply show '/': grep freezer /proc/self/cgroup 9:freezer:/ If instead the same task simply bind mounts the /a/b cgroup directory, the resulting mountinfo entry will again show /a/b for the dentry root. However in this case the task will find its own cgroup at /mnt/a/b, not at /mnt: mount --bind /sys/fs/cgroup/freezer/a/b /mnt 130 25 0:34 /a/b /mnt rw,nosuid,nodev,noexec,relatime shared:21 - cgroup cgroup rw,freezer In other words, there is no way for the task to know, based on what is in mountinfo, which cgroup directory is its own. Example (by mkerrisk): First, a little script to save some typing and verbiage: echo -e "\t/proc/self/cgroup:\t$(cat /proc/self/cgroup | grep freezer)" cat /proc/self/mountinfo | grep freezer | awk '{print "\tmountinfo:\t\t" $4 "\t" $5}' Create cgroup, place this shell into the cgroup, and look at the state of the /proc files: 2653 2653 # Our shell 14254 # cat(1) /proc/self/cgroup: 10:freezer:/a/b mountinfo: / /sys/fs/cgroup/freezer Create a shell in new cgroup and mount namespaces. The act of creating a new cgroup namespace causes the process's current cgroups directories to become its cgroup root directories. (Here, I'm using my own version of the "unshare" utility, which takes the same options as the util-linux version): Look at the state of the /proc files: /proc/self/cgroup: 10:freezer:/ mountinfo: / /sys/fs/cgroup/freezer The third entry in /proc/self/cgroup (the pathname of the cgroup inside the hierarchy) is correctly virtualized w.r.t. the cgroup namespace, which is rooted at /a/b in the outer namespace. However, the info in /proc/self/mountinfo is not for this cgroup namespace, since we are seeing a duplicate of the mount from the old mount namespace, and the info there does not correspond to the new cgroup namespace. However, trying to create a new mount still doesn't show us the right information in mountinfo: # propagating to other mountns /proc/self/cgroup: 7:freezer:/ mountinfo: /a/b /mnt/freezer The act of creating a new cgroup namespace caused the process's current freezer directory, "/a/b", to become its cgroup freezer root directory. In other words, the pathname directory of the directory within the newly mounted cgroup filesystem should be "/", but mountinfo wrongly shows us "/a/b". The consequence of this is that the process in the cgroup namespace cannot correctly construct the pathname of its cgroup root directory from the information in /proc/PID/mountinfo. With this patch, the dentry root field in mountinfo is shown relative to the reader's cgroup namespace. So the same steps as above: /proc/self/cgroup: 10:freezer:/a/b mountinfo: / /sys/fs/cgroup/freezer /proc/self/cgroup: 10:freezer:/ mountinfo: /../.. /sys/fs/cgroup/freezer /proc/self/cgroup: 10:freezer:/ mountinfo: / /mnt/freezer cgroup.clone_children freezer.parent_freezing freezer.state tasks cgroup.procs freezer.self_freezing notify_on_release 3164 2653 # First shell that placed in this cgroup 3164 # Shell started by 'unshare' 14197 # cat(1) Signed-off-by: Serge Hallyn <serge.hallyn@ubuntu.com> Tested-by: Michael Kerrisk <mtk.manpages@gmail.com> Acked-by: Michael Kerrisk <mtk.manpages@gmail.com> Signed-off-by: Tejun Heo <tj@kernel.org>
* | | kernfs_path_from_node_locked: don't overwrite nlenSerge Hallyn2016-05-021-3/+3
|/ / | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We've calculated @len to be the bytes we need for '/..' entries from @kn_from to the common ancestor, and calculated @nlen to be the extra bytes we need to get from the common ancestor to @kn_to. We use them as such at the end. But in the loop copying the actual entries, we overwrite @nlen. Use a temporary variable for that instead. Without this, the return length, when the buffer is large enough, is wrong. (When the buffer is NULL or too small, the returned value is correct. The buffer contents are also correct.) Interestingly, no callers of this function are affected by this as of yet. However the upcoming cgroup_show_path() will be. Signed-off-by: Serge Hallyn <serge.hallyn@ubuntu.com>
* / mm, fs: get rid of PAGE_CACHE_* and page_cache_{get,release} macrosKirill A. Shutemov2016-04-041-2/+2
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} macros were introduced *long* time ago with promise that one day it will be possible to implement page cache with bigger chunks than PAGE_SIZE. This promise never materialized. And unlikely will. We have many places where PAGE_CACHE_SIZE assumed to be equal to PAGE_SIZE. And it's constant source of confusion on whether PAGE_CACHE_* or PAGE_* constant should be used in a particular case, especially on the border between fs and mm. Global switching to PAGE_CACHE_SIZE != PAGE_SIZE would cause to much breakage to be doable. Let's stop pretending that pages in page cache are special. They are not. The changes are pretty straight-forward: - <foo> << (PAGE_CACHE_SHIFT - PAGE_SHIFT) -> <foo>; - <foo> >> (PAGE_CACHE_SHIFT - PAGE_SHIFT) -> <foo>; - PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} -> PAGE_{SIZE,SHIFT,MASK,ALIGN}; - page_cache_get() -> get_page(); - page_cache_release() -> put_page(); This patch contains automated changes generated with coccinelle using script below. For some reason, coccinelle doesn't patch header files. I've called spatch for them manually. The only adjustment after coccinelle is revert of changes to PAGE_CAHCE_ALIGN definition: we are going to drop it later. There are few places in the code where coccinelle didn't reach. I'll fix them manually in a separate patch. Comments and documentation also will be addressed with the separate patch. virtual patch @@ expression E; @@ - E << (PAGE_CACHE_SHIFT - PAGE_SHIFT) + E @@ expression E; @@ - E >> (PAGE_CACHE_SHIFT - PAGE_SHIFT) + E @@ @@ - PAGE_CACHE_SHIFT + PAGE_SHIFT @@ @@ - PAGE_CACHE_SIZE + PAGE_SIZE @@ @@ - PAGE_CACHE_MASK + PAGE_MASK @@ expression E; @@ - PAGE_CACHE_ALIGN(E) + PAGE_ALIGN(E) @@ expression E; @@ - page_cache_get(E) + get_page(E) @@ expression E; @@ - page_cache_release(E) + put_page(E) Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Acked-by: Michal Hocko <mhocko@suse.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Merge branch 'for-4.6-ns' of ↵Linus Torvalds2016-03-212-31/+229
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup Pull cgroup namespace support from Tejun Heo: "These are changes to implement namespace support for cgroup which has been pending for quite some time now. It is very straight-forward and only affects what part of cgroup hierarchies are visible. After unsharing, mounting a cgroup fs will be scoped to the cgroups the task belonged to at the time of unsharing and the cgroup paths exposed to userland would be adjusted accordingly" * 'for-4.6-ns' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup: cgroup: fix and restructure error handling in copy_cgroup_ns() cgroup: fix alloc_cgroup_ns() error handling in copy_cgroup_ns() Add FS_USERNS_FLAG to cgroup fs cgroup: Add documentation for cgroup namespaces cgroup: mount cgroupns-root when inside non-init cgroupns kernfs: define kernfs_node_dentry cgroup: cgroup namespace setns support cgroup: introduce cgroup namespaces sched: new clone flag CLONE_NEWCGROUP for cgroup namespace kernfs: Add API to generate relative kernfs path
| * kernfs: define kernfs_node_dentryAditya Kali2016-02-161-0/+69
| | | | | | | | | | | | | | | | | | | | Add a new kernfs api is added to lookup the dentry for a particular kernfs path. Signed-off-by: Aditya Kali <adityakali@google.com> Signed-off-by: Serge E. Hallyn <serge.hallyn@canonical.com> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Tejun Heo <tj@kernel.org>
| * kernfs: Add API to generate relative kernfs pathAditya Kali2016-02-161-31/+160
| | | | | | | | | | | | | | | | | | | | The new function kernfs_path_from_node() generates and returns kernfs path of a given kernfs_node relative to a given parent kernfs_node. Signed-off-by: Aditya Kali <adityakali@google.com> Signed-off-by: Serge E. Hallyn <serge.hallyn@canonical.com> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Tejun Heo <tj@kernel.org>
* | kernfs: make kernfs_walk_ns() use kernfs_pr_cont_buf[]Tejun Heo2016-02-081-5/+14
| | | | | | | | | | | | | | | | | | | | | | kernfs_walk_ns() uses a static path_buf[PATH_MAX] to separate out path components. Keeping around the 4k buffer just for kernfs_walk_ns() is wasteful. This patch makes it piggyback on kernfs_pr_cont_buf[] instead. This requires kernfs_walk_ns() to hold kernfs_rename_lock. Signed-off-by: Tejun Heo <tj@kernel.org> Reported-by: Geert Uytterhoeven <geert@linux-m68k.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* | wrappers for ->i_mutex accessAl Viro2016-01-231-2/+2
|/ | | | | | | | | | | parallel to mutex_{lock,unlock,trylock,is_locked,lock_nested}, inode_foo(inode) being mutex_foo(&inode->i_mutex). Please, use those for access to ->i_mutex; over the coming cycle ->i_mutex will become rwsem, with ->lookup() done with it held only shared. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* Revert "kernfs: do not account ino_ida allocations to memcg"Vladimir Davydov2016-01-151-8/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently, all kmem allocations (namely every kmem_cache_alloc, kmalloc, alloc_kmem_pages call) are accounted to memory cgroup automatically. Callers have to explicitly opt out if they don't want/need accounting for some reason. Such a design decision leads to several problems: - kmalloc users are highly sensitive to failures, many of them implicitly rely on the fact that kmalloc never fails, while memcg makes failures quite plausible. - A lot of objects are shared among different containers by design. Accounting such objects to one of containers is just unfair. Moreover, it might lead to pinning a dead memcg along with its kmem caches, which aren't tiny, which might result in noticeable increase in memory consumption for no apparent reason in the long run. - There are tons of short-lived objects. Accounting them to memcg will only result in slight noise and won't change the overall picture, but we still have to pay accounting overhead. For more info, see - http://lkml.kernel.org/r/20151105144002.GB15111%40dhcp22.suse.cz - http://lkml.kernel.org/r/20151106090555.GK29259@esperanza Therefore this patchset switches to the white list policy. Now kmalloc users have to explicitly opt in by passing __GFP_ACCOUNT flag. Currently, the list of accounted objects is quite limited and only includes those allocations that (1) are known to be easily triggered from userspace and (2) can fail gracefully (for the full list see patch no. 6) and it still misses many object types. However, accounting only those objects should be a satisfactory approximation of the behavior we used to have for most sane workloads. This patch (of 6): Revert 499611ed451508a42d1d7d ("kernfs: do not account ino_ida allocations to memcg"). Black-list kmem accounting policy (aka __GFP_NOACCOUNT) turned out to be fragile and difficult to maintain, because there seem to be many more allocations that should not be accounted than those that should be. Besides, false accounting an allocation might result in much worse consequences than not accounting at all, namely increased memory consumption due to pinned dead kmem caches. So it was decided to switch to the white-list policy. This patch reverts bits introducing the black-list policy. The white-list policy will be introduced later in the series. Signed-off-by: Vladimir Davydov <vdavydov@virtuozzo.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@kernel.org> Cc: Tejun Heo <tj@kernel.org> Cc: Greg Thelen <gthelen@google.com> Cc: Christoph Lameter <cl@linux.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: David Rientjes <rientjes@google.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-nextLinus Torvalds2016-01-131-0/+46
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull networking updates from Davic Miller: 1) Support busy polling generically, for all NAPI drivers. From Eric Dumazet. 2) Add byte/packet counter support to nft_ct, from Floriani Westphal. 3) Add RSS/XPS support to mvneta driver, from Gregory Clement. 4) Implement IPV6_HDRINCL socket option for raw sockets, from Hannes Frederic Sowa. 5) Add support for T6 adapter to cxgb4 driver, from Hariprasad Shenai. 6) Add support for VLAN device bridging to mlxsw switch driver, from Ido Schimmel. 7) Add driver for Netronome NFP4000/NFP6000, from Jakub Kicinski. 8) Provide hwmon interface to mlxsw switch driver, from Jiri Pirko. 9) Reorganize wireless drivers into per-vendor directories just like we do for ethernet drivers. From Kalle Valo. 10) Provide a way for administrators "destroy" connected sockets via the SOCK_DESTROY socket netlink diag operation. From Lorenzo Colitti. 11) Add support to add/remove multicast routes via netlink, from Nikolay Aleksandrov. 12) Make TCP keepalive settings per-namespace, from Nikolay Borisov. 13) Add forwarding and packet duplication facilities to nf_tables, from Pablo Neira Ayuso. 14) Dead route support in MPLS, from Roopa Prabhu. 15) TSO support for thunderx chips, from Sunil Goutham. 16) Add driver for IBM's System i/p VNIC protocol, from Thomas Falcon. 17) Rationalize, consolidate, and more completely document the checksum offloading facilities in the networking stack. From Tom Herbert. 18) Support aborting an ongoing scan in mac80211/cfg80211, from Vidyullatha Kanchanapally. 19) Use per-bucket spinlock for bpf hash facility, from Tom Leiming. * git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next: (1375 commits) net: bnxt: always return values from _bnxt_get_max_rings net: bpf: reject invalid shifts phonet: properly unshare skbs in phonet_rcv() dwc_eth_qos: Fix dma address for multi-fragment skbs phy: remove an unneeded condition mdio: remove an unneed condition mdio_bus: NULL dereference on allocation error net: Fix typo in netdev_intersect_features net: freescale: mac-fec: Fix build error from phy_device API change net: freescale: ucc_geth: Fix build error from phy_device API change bonding: Prevent IPv6 link local address on enslaved devices IB/mlx5: Add flow steering support net/mlx5_core: Export flow steering API net/mlx5_core: Make ipv4/ipv6 location more clear net/mlx5_core: Enable flow steering support for the IB driver net/mlx5_core: Initialize namespaces only when supported by device net/mlx5_core: Set priority attributes net/mlx5_core: Connect flow tables net/mlx5_core: Introduce modify flow table command net/mlx5_core: Managing root flow table ...
| * kernfs: implement kernfs_walk_and_get()Tejun Heo2015-11-201-0/+46
| | | | | | | | | | | | | | | | | | | | | | | | Implement kernfs_walk_and_get() which is similar to kernfs_find_and_get() but can walk a path instead of just a name. v2: Use strlcpy() instead of strlen() + memcpy() as suggested by David. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: David Miller <davem@davemloft.net>
* | Merge branch 'work.xattr' of ↵Linus Torvalds2016-01-111-2/+2
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull vfs xattr updates from Al Viro: "Andreas' xattr cleanup series. It's a followup to his xattr work that went in last cycle; -0.5KLoC" * 'work.xattr' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: xattr handlers: Simplify list operation ocfs2: Replace list xattr handler operations nfs: Move call to security_inode_listsecurity into nfs_listxattr xfs: Change how listxattr generates synthetic attributes tmpfs: listxattr should include POSIX ACL xattrs tmpfs: Use xattr handler infrastructure btrfs: Use xattr handler infrastructure vfs: Distinguish between full xattr names and proper prefixes posix acls: Remove duplicate xattr name definitions gfs2: Remove gfs2_xattr_acl_chmod vfs: Remove vfs_xattr_cmp
| * | tmpfs: listxattr should include POSIX ACL xattrsAndreas Gruenbacher2015-12-071-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When a file on tmpfs has an ACL or a Default ACL, listxattr should include the corresponding xattr name. Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com> Reviewed-by: James Morris <james.l.morris@oracle.com> Cc: Hugh Dickins <hughd@google.com> Cc: linux-mm@kvack.org Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * | tmpfs: Use xattr handler infrastructureAndreas Gruenbacher2015-12-071-1/+1
| |/ | | | | | | | | | | | | | | | | | | | | | | | | Use the VFS xattr handler infrastructure and get rid of similar code in the filesystem. For implementing shmem_xattr_handler_set, we need a version of simple_xattr_set which removes the attribute when value is NULL. Use this to implement kernfs_iop_removexattr as well. Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com> Reviewed-by: James Morris <james.l.morris@oracle.com> Cc: Hugh Dickins <hughd@google.com> Cc: linux-mm@kvack.org Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* | switch ->get_link() to delayed_call, kill ->put_link()Al Viro2015-12-301-9/+10
| | | | | | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* | kill free_page_put_link()Al Viro2015-12-291-6/+6
| | | | | | | | | | | | all callers are better off with kfree_put_link() Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* | replace ->follow_link() with new method that could stay in RCU modeAl Viro2015-12-091-3/+8
|/ | | | | | | | | | | | | | | | | | new method: ->get_link(); replacement of ->follow_link(). The differences are: * inode and dentry are passed separately * might be called both in RCU and non-RCU mode; the former is indicated by passing it a NULL dentry. * when called that way it isn't allowed to block and should return ERR_PTR(-ECHILD) if it needs to be called in non-RCU mode. It's a flagday change - the old method is gone, all in-tree instances converted. Conversion isn't hard; said that, so far very few instances do not immediately bail out when called in RCU mode. That'll change in the next commits. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* kernfs: implement kernfs_path_len()Tejun Heo2015-08-191-0/+23
| | | | | | | | | Add a function to determine the path length of a kernfs node. This for now will be used by writeback tracepoint updates. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Jens Axboe <axboe@fb.com>
* Merge branch 'for-linus' of ↵Linus Torvalds2015-07-042-1/+39
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace Pull user namespace updates from Eric Biederman: "Long ago and far away when user namespaces where young it was realized that allowing fresh mounts of proc and sysfs with only user namespace permissions could violate the basic rule that only root gets to decide if proc or sysfs should be mounted at all. Some hacks were put in place to reduce the worst of the damage could be done, and the common sense rule was adopted that fresh mounts of proc and sysfs should allow no more than bind mounts of proc and sysfs. Unfortunately that rule has not been fully enforced. There are two kinds of gaps in that enforcement. Only filesystems mounted on empty directories of proc and sysfs should be ignored but the test for empty directories was insufficient. So in my tree directories on proc, sysctl and sysfs that will always be empty are created specially. Every other technique is imperfect as an ordinary directory can have entries added even after a readdir returns and shows that the directory is empty. Special creation of directories for mount points makes the code in the kernel a smidge clearer about it's purpose. I asked container developers from the various container projects to help test this and no holes were found in the set of mount points on proc and sysfs that are created specially. This set of changes also starts enforcing the mount flags of fresh mounts of proc and sysfs are consistent with the existing mount of proc and sysfs. I expected this to be the boring part of the work but unfortunately unprivileged userspace winds up mounting fresh copies of proc and sysfs with noexec and nosuid clear when root set those flags on the previous mount of proc and sysfs. So for now only the atime, read-only and nodev attributes which userspace happens to keep consistent are enforced. Dealing with the noexec and nosuid attributes remains for another time. This set of changes also addresses an issue with how open file descriptors from /proc/<pid>/ns/* are displayed. Recently readlink of /proc/<pid>/fd has been triggering a WARN_ON that has not been meaningful since it was added (as all of the code in the kernel was converted) and is not now actively wrong. There is also a short list of issues that have not been fixed yet that I will mention briefly. It is possible to rename a directory from below to above a bind mount. At which point any directory pointers below the renamed directory can be walked up to the root directory of the filesystem. With user namespaces enabled a bind mount of the bind mount can be created allowing the user to pick a directory whose children they can rename to outside of the bind mount. This is challenging to fix and doubly so because all obvious solutions must touch code that is in the performance part of pathname resolution. As mentioned above there is also a question of how to ensure that developers by accident or with purpose do not introduce exectuable files on sysfs and proc and in doing so introduce security regressions in the current userspace that will not be immediately obvious and as such are likely to require breaking userspace in painful ways once they are recognized" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace: vfs: Remove incorrect debugging WARN in prepend_path mnt: Update fs_fully_visible to test for permanently empty directories sysfs: Create mountpoints with sysfs_create_mount_point sysfs: Add support for permanently empty directories to serve as mount points. kernfs: Add support for always empty directories. proc: Allow creating permanently empty directories that serve as mount points sysctl: Allow creating permanently empty directories that serve as mountpoints. fs: Add helper functions for permanently empty directories. vfs: Ignore unlocked mounts in fs_fully_visible mnt: Modify fs_fully_visible to deal with locked ro nodev and atime mnt: Refactor the logic for mounting sysfs and proc in a user namespace
| * kernfs: Add support for always empty directories.Eric W. Biederman2015-07-012-1/+39
| | | | | | | | | | | | | | | | | | | | | | | | | | 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. Cc: stable@vger.kernel.org Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
* | Merge branch 'for-4.2' of ↵Linus Torvalds2015-06-271-1/+0
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup Pull cgroup updates from Tejun Heo: - threadgroup_lock got reorganized so that its users can pick the actual locking mechanism to use. Its only user - cgroups - is updated to use a percpu_rwsem instead of per-process rwsem. This makes things a bit lighter on hot paths and allows cgroups to perform and fail multi-task (a process) migrations atomically. Multi-task migrations are used in several places including the unified hierarchy. - Delegation rule and documentation added to unified hierarchy. This will likely be the last interface update from the cgroup core side for unified hierarchy before lifting the devel mask. - Some groundwork for the pids controller which is scheduled to be merged in the coming devel cycle. * 'for-4.2' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup: cgroup: add delegation section to unified hierarchy documentation cgroup: require write perm on common ancestor when moving processes on the default hierarchy cgroup: separate out cgroup_procs_write_permission() from __cgroup_procs_write() kernfs: make kernfs_get_inode() public MAINTAINERS: add a cgroup core co-maintainer cgroup: fix uninitialised iterator in for_each_subsys_which cgroup: replace explicit ss_mask checking with for_each_subsys_which cgroup: use bitmask to filter for_each_subsys cgroup: add seq_file forward declaration for struct cftype cgroup: simplify threadgroup locking sched, cgroup: replace signal_struct->group_rwsem with a global percpu_rwsem sched, cgroup: reorganize threadgroup locking cgroup: switch to unsigned long for bitmasks cgroup: reorganize include/linux/cgroup.h cgroup: separate out include/linux/cgroup-defs.h cgroup: fix some comment typos
| * | kernfs: make kernfs_get_inode() publicTejun Heo2015-06-181-1/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Move kernfs_get_inode() prototype from fs/kernfs/kernfs-internal.h to include/linux/kernfs.h. It obtains the matching inode for a kernfs_node. It will be used by cgroup for inode based permission checks for now but is generally useful. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* | | Merge tag 'driver-core-4.2-rc1' of ↵Linus Torvalds2015-06-271-1/+0
|\ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core Pull driver core updates from Greg KH: "Here is the driver core / firmware changes for 4.2-rc1. A number of small changes all over the place in the driver core, and in the firmware subsystem. Nothing really major, full details in the shortlog. Some of it is a bit of churn, given that the platform driver probing changes was found to not work well, so they were reverted. All of these have been in linux-next for a while with no reported issues" * tag 'driver-core-4.2-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (31 commits) Revert "base/platform: Only insert MEM and IO resources" Revert "base/platform: Continue on insert_resource() error" Revert "of/platform: Use platform_device interface" Revert "base/platform: Remove code duplication" firmware: add missing kfree for work on async call fs: sysfs: don't pass count == 0 to bin file readers base:dd - Fix for typo in comment to function driver_deferred_probe_trigger(). base/platform: Remove code duplication of/platform: Use platform_device interface base/platform: Continue on insert_resource() error base/platform: Only insert MEM and IO resources firmware: use const for remaining firmware names firmware: fix possible use after free on name on asynchronous request firmware: check for file truncation on direct firmware loading firmware: fix __getname() missing failure check drivers: of/base: move of_init to driver_init drivers/base: cacheinfo: fix annoying typo when DT nodes are absent sysfs: disambiguate between "error code" and "failure" in comments driver-core: fix build for !CONFIG_MODULES driver-core: make __device_attach() static ...
| * | | kernfs: remove outdated and confusing commentWolfram Sang2015-05-241-1/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Grabbing the parent is not happening anymore since 2010 (e72ceb8ccac5f7 "sysfs: Remove sysfs_get/put_active_two"). Remove this confusing comment. Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com> Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* | | | Merge branch 'for-linus-1' of ↵Linus Torvalds2015-06-221-16/+9
|\ \ \ \ | |/ / / |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull vfs updates from Al Viro: "In this pile: pathname resolution rewrite. - recursion in link_path_walk() is gone. - nesting limits on symlinks are gone (the only limit remaining is that the total amount of symlinks is no more than 40, no matter how nested). - "fast" (inline) symlinks are handled without leaving rcuwalk mode. - stack footprint (independent of the nesting) is below kilobyte now, about on par with what it used to be with one level of nested symlinks and ~2.8 times lower than it used to be in the worst case. - struct nameidata is entirely private to fs/namei.c now (not even opaque pointers are being passed around). - ->follow_link() and ->put_link() calling conventions had been changed; all in-tree filesystems converted, out-of-tree should be able to follow reasonably easily. For out-of-tree conversions, see Documentation/filesystems/porting for details (and in-tree filesystems for examples of conversion). That has sat in -next since mid-May, seems to survive all testing without regressions and merges clean with v4.1" * 'for-linus-1' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (131 commits) turn user_{path_at,path,lpath,path_dir}() into static inlines namei: move saved_nd pointer into struct nameidata inline user_path_create() inline user_path_parent() namei: trim do_last() arguments namei: stash dfd and name into nameidata namei: fold path_cleanup() into terminate_walk() namei: saner calling conventions for filename_parentat() namei: saner calling conventions for filename_create() namei: shift nameidata down into filename_parentat() namei: make filename_lookup() reject ERR_PTR() passed as name namei: shift nameidata inside filename_lookup() namei: move putname() call into filename_lookup() namei: pass the struct path to store the result down into path_lookupat() namei: uninline set_root{,_rcu}() namei: be careful with mountpoint crossings in follow_dotdot_rcu() Documentation: remove outdated information from automount-support.txt get rid of assorted nameidata-related debris lustre: kill unused helper lustre: kill unused macro (LOOKUP_CONTINUE) ...
| * | | new helper: free_page_put_link()Al Viro2015-05-111-6/+1
| | | | | | | | | | | | | | | | | | | | | | | | similar to kfree_put_link() Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * | | switch ->put_link() from dentry to inodeAl Viro2015-05-111-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | only one instance looks at that argument at all; that sole exception wants inode rather than dentry. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * | | don't pass nameidata to ->follow_link()Al Viro2015-05-111-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | its only use is getting passed to nd_jump_link(), which can obtain it from current->nameidata Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * | | new ->follow_link() and ->put_link() calling conventionsAl Viro2015-05-111-12/+10
| | |/ | |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | a) instead of storing the symlink body (via nd_set_link()) and returning an opaque pointer later passed to ->put_link(), ->follow_link() _stores_ that opaque pointer (into void * passed by address by caller) and returns the symlink body. Returning ERR_PTR() on error, NULL on jump (procfs magic symlinks) and pointer to symlink body for normal symlinks. Stored pointer is ignored in all cases except the last one. Storing NULL for opaque pointer (or not storing it at all) means no call of ->put_link(). b) the body used to be passed to ->put_link() implicitly (via nameidata). Now only the opaque pointer is. In the cases when we used the symlink body to free stuff, ->follow_link() now should store it as opaque pointer in addition to returning it. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* / | kernfs: do not account ino_ida allocations to memcgVladimir Davydov2015-05-151-1/+8
|/ / | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | root->ino_ida is used for kernfs inode number allocations. Since IDA has a layered structure, different IDs can reside on the same layer, which is currently accounted to some memory cgroup. The problem is that each kmem cache of a memory cgroup has its own directory on sysfs (under /sys/fs/kernel/<cache-name>/cgroup). If the inode number of such a directory or any file in it gets allocated from a layer accounted to the cgroup which the cache is created for, the cgroup will get pinned for good, because one has to free all kmem allocations accounted to a cgroup in order to release it and destroy all its kmem caches. That said we must not account layers of ino_ida to any memory cgroup. Since per net init operations may create new sysfs entries directly (e.g. lo device) or indirectly (nf_conntrack creates a new kmem cache per each namespace, which, in turn, creates new sysfs entries), an easy way to reproduce this issue is by creating network namespace(s) from inside a kmem-active memory cgroup. Signed-off-by: Vladimir Davydov <vdavydov@parallels.com> Acked-by: Tejun Heo <tj@kernel.org> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@suse.cz> Cc: Christoph Lameter <cl@linux.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: David Rientjes <rientjes@google.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Greg Thelen <gthelen@google.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: <stable@vger.kernel.org> [4.0.x] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* / VFS: normal filesystems (and lustre): d_inode() annotationsDavid Howells2015-04-152-5/+5
|/ | | | | | | that's the bulk of filesystem drivers dealing with inodes of their own Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* kernfs: handle poll correctly on 'direct_read' files.NeilBrown2015-03-161-0/+1
| | | | | | | | | | | | | | | | | | | | Kernfs supports two styles of read: direct_read and seqfile_read. The latter supports 'poll' correctly thanks to the update of '->event' in kernfs_seq_show. The former does not as '->event' is never updated on a read. So add an appropriate update in kernfs_file_direct_read(). This was noticed because some 'md' sysfs attributes were recently changed to use direct reads. Reported-by: Prakash Punnoor <prakash@punnoor.de> Reported-by: Torsten Kaiser <just.for.lkml@googlemail.com> Fixes: 750f199ee8b578062341e6ddfe36c59ac8ff2dcb Signed-off-by: NeilBrown <neilb@suse.de> Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* kernfs: remove KERNFS_STATIC_NAMETejun Heo2015-02-142-16/+8
| | | | | | | | | | | | | | | | | When a new kernfs node is created, KERNFS_STATIC_NAME is used to avoid making a separate copy of its name. It's currently only used for sysfs attributes whose filenames are required to stay accessible and unchanged. There are rare exceptions where these names are allocated and formatted dynamically but for the vast majority of cases they're consts in the rodata section. Now that kernfs is converted to use kstrdup_const() and kfree_const(), there's little point in keeping KERNFS_STATIC_NAME around. Remove it. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Andrzej Hajda <a.hajda@samsung.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* kernfs: convert node name allocation to kstrdup_constAndrzej Hajda2015-02-141-6/+6
| | | | | | | | | | | | | | | | | | | | | sysfs frequently performs duplication of strings located in read-only memory section. Replacing kstrdup by kstrdup_const allows to avoid such operations. Signed-off-by: Andrzej Hajda <a.hajda@samsung.com> Cc: Marek Szyprowski <m.szyprowski@samsung.com> Cc: Kyungmin Park <kyungmin.park@samsung.com> Cc: Mike Turquette <mturquette@linaro.org> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Christoph Lameter <cl@linux.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: David Rientjes <rientjes@google.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Acked-by: Tejun Heo <tj@kernel.org> Cc: Greg KH <greg@kroah.com> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* fs: remove mapping->backing_dev_infoChristoph Hellwig2015-01-201-1/+0
| | | | | | | | | | | Now that we never use the backing_dev_info pointer in struct address_space we can simply remove it and save 4 to 8 bytes in every inode. Signed-off-by: Christoph Hellwig <hch@lst.de> Acked-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp> Reviewed-by: Tejun Heo <tj@kernel.org> Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: Jens Axboe <axboe@fb.com>
* fs: deduplicate noop_backing_dev_infoChristoph Hellwig2015-01-203-15/+1
| | | | | | | | | | hugetlbfs, kernfs and dlmfs can simply use noop_backing_dev_info instead of creating a local duplicate. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Jan Kara <jack@suse.cz> Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jens Axboe <axboe@fb.com>
* kernfs: Fix kernfs_name_compareRasmus Villemoes2015-01-101-4/+8
| | | | | | | | | | | | | | | | Returning a difference from a comparison functions is usually wrong (see acbbe6fbb240 "kcmp: fix standard comparison bug" for the long story). Here there is the additional twist that if the void pointers ns and kn->ns happen to differ by a multiple of 2^32, kernfs_name_compare returns 0, falsely reporting a match to the caller. Technically 'hash - kn->hash' is ok since the hashes are restricted to 31 bits, but it's better to avoid that subtlety. Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk> Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* vm_area_operations: kill ->migrate()Al Viro2014-12-171-22/+0
| | | | | | | the only instance this method has ever grown was one in kernfs - one that call ->migrate() of another vm_ops if it exists. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* Merge tag 'driver-core-3.19-rc1' of ↵Linus Torvalds2014-12-151-23/+50
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core Pull driver core update from Greg KH: "Here's the set of driver core patches for 3.19-rc1. They are dominated by the removal of the .owner field in platform drivers. They touch a lot of files, but they are "simple" changes, just removing a line in a structure. Other than that, a few minor driver core and debugfs changes. There are some ath9k patches coming in through this tree that have been acked by the wireless maintainers as they relied on the debugfs changes. Everything has been in linux-next for a while" * tag 'driver-core-3.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (324 commits) Revert "ath: ath9k: use debugfs_create_devm_seqfile() helper for seq_file entries" fs: debugfs: add forward declaration for struct device type firmware class: Deletion of an unnecessary check before the function call "vunmap" firmware loader: fix hung task warning dump devcoredump: provide a one-way disable function device: Add dev_<level>_once variants ath: ath9k: use debugfs_create_devm_seqfile() helper for seq_file entries ath: use seq_file api for ath9k debugfs files debugfs: add helper function to create device related seq_file drivers/base: cacheinfo: remove noisy error boot message Revert "core: platform: add warning if driver has no owner" drivers: base: support cpu cache information interface to userspace via sysfs drivers: base: add cpu_device_create to support per-cpu devices topology: replace custom attribute macros with standard DEVICE_ATTR* cpumask: factor out show_cpumap into separate helper function driver core: Fix unbalanced device reference in drivers_probe driver core: fix race with userland in device_add() sysfs/kernfs: make read requests on pre-alloc files use the buffer. sysfs/kernfs: allow attributes to request write buffer be pre-allocated. fs: sysfs: return EGBIG on write if offset is larger than file size ...
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