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* fs: Better permission checking for submountsEric W. Biederman2022-10-28
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 93faccbbfa958a9668d3ab4e30f38dd205cee8d8 upstream. To support unprivileged users mounting filesystems two permission checks have to be performed: a test to see if the user allowed to create a mount in the mount namespace, and a test to see if the user is allowed to access the specified filesystem. The automount case is special in that mounting the original filesystem grants permission to mount the sub-filesystems, to any user who happens to stumble across the their mountpoint and satisfies the ordinary filesystem permission checks. Attempting to handle the automount case by using override_creds almost works. It preserves the idea that permission to mount the original filesystem is permission to mount the sub-filesystem. Unfortunately using override_creds messes up the filesystems ordinary permission checks. Solve this by being explicit that a mount is a submount by introducing vfs_submount, and using it where appropriate. vfs_submount uses a new mount internal mount flags MS_SUBMOUNT, to let sget and friends know that a mount is a submount so they can take appropriate action. sget and sget_userns are modified to not perform any permission checks on submounts. follow_automount is modified to stop using override_creds as that has proven problemantic. do_mount is modified to always remove the new MS_SUBMOUNT flag so that we know userspace will never by able to specify it. autofs4 is modified to stop using current_real_cred that was put in there to handle the previous version of submount permission checking. cifs is modified to pass the mountpoint all of the way down to vfs_submount. debugfs is modified to pass the mountpoint all of the way down to trace_automount by adding a new parameter. To make this change easier a new typedef debugfs_automount_t is introduced to capture the type of the debugfs automount function. Fixes: 069d5ac9ae0d ("autofs: Fix automounts by using current_real_cred()->uid") Fixes: aeaa4a79ff6a ("fs: Call d_automount with the filesystems creds") Reviewed-by: Trond Myklebust <trond.myklebust@primarydata.com> Reviewed-by: Seth Forshee <seth.forshee@canonical.com> Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Change-Id: I09cb1f35368fb8dc4a64b5ac5a35c9d2843ef95b
* mnt: Move the FS_USERNS_MOUNT check into sget_usernsEric W. Biederman2022-10-28
| | | | | | | | | | | Allowing a filesystem to be mounted by other than root in the initial user namespace is a filesystem property not a mount namespace property and as such should be checked in filesystem specific code. Move the FS_USERNS_MOUNT test into super.c:sget_userns(). Acked-by: Seth Forshee <seth.forshee@canonical.com> Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com> Change-Id: I5da9f5ce3e7b85379a771617e3238817b777eab4
* fs: Add user namespace member to struct super_blockEric W. Biederman2022-04-19
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Start marking filesystems with a user namespace owner, s_user_ns. In this change this is only used for permission checks of who may mount a filesystem. Ultimately s_user_ns will be used for translating ids and checking capabilities for filesystems mounted from user namespaces. The default policy for setting s_user_ns is implemented in sget(), which arranges for s_user_ns to be set to current_user_ns() and to ensure that the mounter of the filesystem has CAP_SYS_ADMIN in that user_ns. The guts of sget are split out into another function sget_userns(). The function sget_userns calls alloc_super with the specified user namespace or it verifies the existing superblock that was found has the expected user namespace, and fails with EBUSY when it is not. This failing prevents users with the wrong privileges mounting a filesystem. The reason for the split of sget_userns from sget is that in some cases such as mount_ns and kernfs_mount_ns a different policy for permission checking of mounts and setting s_user_ns is necessary, and the existence of sget_userns() allows those policies to be implemented. The helper mount_ns is expected to be used for filesystems such as proc and mqueuefs which present per namespace information. The function mount_ns is modified to call sget_userns instead of sget to ensure the user namespace owner of the namespace whose information is presented by the filesystem is used on the superblock. For sysfs and cgroup the appropriate permission checks are already in place, and kernfs_mount_ns is modified to call sget_userns so that the init_user_ns is the only user namespace used. For the cgroup filesystem cgroup namespace mounts are bind mounts of a subset of the full cgroup filesystem and as such s_user_ns must be the same for all of them as there is only a single superblock. Mounts of sysfs that vary based on the network namespace could in principle change s_user_ns but it keeps the analysis and implementation of kernfs simpler if that is not supported, and at present there appear to be no benefits from supporting a different s_user_ns on any sysfs mount. Getting the details of setting s_user_ns correct has been a long process. Thanks to Pavel Tikhorirorv who spotted a leak in sget_userns. Thanks to Seth Forshee who has kept the work alive. Thanks-to: Seth Forshee <seth.forshee@canonical.com> Thanks-to: Pavel Tikhomirov <ptikhomirov@virtuozzo.com> Acked-by: Seth Forshee <seth.forshee@canonical.com> Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Chatur27 <jasonbright2709@gmail.com>
* vfs: Pass data, ns, and ns->userns to mount_nsEric W. Biederman2022-04-19
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | Today what is normally called data (the mount options) is not passed to fill_super through mount_ns. Pass the mount options and the namespace separately to mount_ns so that filesystems such as proc that have mount options, can use mount_ns. Pass the user namespace to mount_ns so that the standard permission check that verifies the mounter has permissions over the namespace can be performed in mount_ns instead of in each filesystems .mount method. Thus removing the duplication between mqueuefs and proc in terms of permission checks. The extra permission check does not currently affect the rpc_pipefs filesystem and the nfsd filesystem as those filesystems do not currently allow unprivileged mounts. Without unpvileged mounts it is guaranteed that the caller has already passed capable(CAP_SYS_ADMIN) which guarantees extra permission check will pass. Update rpc_pipefs and the nfsd filesystem to ensure that the network namespace reference is always taken in fill_super and always put in kill_sb so that the logic is simpler and so that errors originating inside of fill_super do not cause a network namespace leak. Acked-by: Seth Forshee <seth.forshee@canonical.com> Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: Chatur27 <jasonbright2709@gmail.com>
* Merge android-4.4.173 (64b5644) into msm-4.4Srinivasarao P2019-02-08
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * refs/heads/tmp-64b5644 Linux 4.4.173 fs: don't scan the inode cache before SB_BORN is set mm: migrate: don't rely on __PageMovable() of newpage after unlocking it drivers: core: Remove glue dirs from sysfs earlier cifs: Always resolve hostname before reconnecting mm, oom: fix use-after-free in oom_kill_process kernel/exit.c: release ptraced tasks before zap_pid_ns_processes mmc: sdhci-iproc: handle mmc_of_parse() errors during probe platform/x86: asus-nb-wmi: Drop mapping of 0x33 and 0x34 scan codes platform/x86: asus-nb-wmi: Map 0x35 to KEY_SCREENLOCK gfs2: Revert "Fix loop in gfs2_rbm_find" arm64: hyp-stub: Forbid kprobing of the hyp-stub ARM: cns3xxx: Fix writing to wrong PCI config registers after alignment fs/dcache: Fix incorrect nr_dentry_unused accounting in shrink_dcache_sb() CIFS: Do not count -ENODATA as failure for query directory l2tp: fix reading optional fields of L2TPv3 l2tp: remove l2specific_len dependency in l2tp_core ucc_geth: Reset BQL queue when stopping device net/rose: fix NULL ax25_cb kernel panic netrom: switch to sock timer API net/mlx4_core: Add masking for a few queries on HCA caps l2tp: copy 4 more bytes to linear part if necessary ipv6: Consider sk_bound_dev_if when binding a socket to an address fs: add the fsnotify call to vfs_iter_write s390/smp: Fix calling smp_call_ipl_cpu() from ipl CPU Revert "loop: Fold __loop_release into loop_release" Revert "loop: Get rid of loop_index_mutex" Revert "loop: Fix double mutex_unlock(&loop_ctl_mutex) in loop_control_ioctl()" f2fs: read page index before freeing arm64: mm: remove page_mapping check in __sync_icache_dcache irqchip/gic-v3-its: Align PCI Multi-MSI allocation on their size perf unwind: Take pgoff into account when reporting elf to libdwfl perf unwind: Unwind with libdw doesn't take symfs into account vt: invoke notifier on screen size change can: bcm: check timer values before ktime conversion can: dev: __can_get_echo_skb(): fix bogous check for non-existing skb by removing it x86/kaslr: Fix incorrect i8254 outb() parameters KVM: x86: Fix single-step debugging Input: xpad - add support for SteelSeries Stratus Duo CIFS: Fix possible hang during async MTU reads and writes tty/n_hdlc: fix __might_sleep warning tty: Handle problem if line discipline does not have receive_buf staging: rtl8188eu: Add device code for D-Link DWA-121 rev B1 char/mwave: fix potential Spectre v1 vulnerability s390/smp: fix CPU hotplug deadlock with CPU rescan s390/early: improve machine detection ARC: perf: map generic branches to correct hardware condition ASoC: atom: fix a missing check of snd_pcm_lib_malloc_pages USB: serial: pl2303: add new PID to support PL2303TB USB: serial: simple: add Motorola Tetra TPG2200 device id net: bridge: Fix ethernet header pointer before check skb forwardable net_sched: refetch skb protocol for each filter net: ipv4: Fix memory leak in network namespace dismantle openvswitch: Avoid OOB read when parsing flow nlattrs net: Fix usage of pskb_trim_rcsum UPSTREAM: binder: filter out nodes when showing binder procs ANDROID: cuttlefish_defconfig: Enable CONFIG_RTC_HCTOSYS Conflicts: mm/migrate.c Change-Id: I7986dc89d88607986d00d56f01812fe806d7f4dc Signed-off-by: Srinivasarao P <spathi@codeaurora.org>
| * Merge 4.4.173 into android-4.4Greg Kroah-Hartman2019-02-07
| |\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Changes in 4.4.173 net: Fix usage of pskb_trim_rcsum openvswitch: Avoid OOB read when parsing flow nlattrs net: ipv4: Fix memory leak in network namespace dismantle net_sched: refetch skb protocol for each filter net: bridge: Fix ethernet header pointer before check skb forwardable USB: serial: simple: add Motorola Tetra TPG2200 device id USB: serial: pl2303: add new PID to support PL2303TB ASoC: atom: fix a missing check of snd_pcm_lib_malloc_pages ARC: perf: map generic branches to correct hardware condition s390/early: improve machine detection s390/smp: fix CPU hotplug deadlock with CPU rescan char/mwave: fix potential Spectre v1 vulnerability staging: rtl8188eu: Add device code for D-Link DWA-121 rev B1 tty: Handle problem if line discipline does not have receive_buf tty/n_hdlc: fix __might_sleep warning CIFS: Fix possible hang during async MTU reads and writes Input: xpad - add support for SteelSeries Stratus Duo KVM: x86: Fix single-step debugging x86/kaslr: Fix incorrect i8254 outb() parameters can: dev: __can_get_echo_skb(): fix bogous check for non-existing skb by removing it can: bcm: check timer values before ktime conversion vt: invoke notifier on screen size change perf unwind: Unwind with libdw doesn't take symfs into account perf unwind: Take pgoff into account when reporting elf to libdwfl irqchip/gic-v3-its: Align PCI Multi-MSI allocation on their size arm64: mm: remove page_mapping check in __sync_icache_dcache f2fs: read page index before freeing Revert "loop: Fix double mutex_unlock(&loop_ctl_mutex) in loop_control_ioctl()" Revert "loop: Get rid of loop_index_mutex" Revert "loop: Fold __loop_release into loop_release" s390/smp: Fix calling smp_call_ipl_cpu() from ipl CPU fs: add the fsnotify call to vfs_iter_write ipv6: Consider sk_bound_dev_if when binding a socket to an address l2tp: copy 4 more bytes to linear part if necessary net/mlx4_core: Add masking for a few queries on HCA caps netrom: switch to sock timer API net/rose: fix NULL ax25_cb kernel panic ucc_geth: Reset BQL queue when stopping device l2tp: remove l2specific_len dependency in l2tp_core l2tp: fix reading optional fields of L2TPv3 CIFS: Do not count -ENODATA as failure for query directory fs/dcache: Fix incorrect nr_dentry_unused accounting in shrink_dcache_sb() ARM: cns3xxx: Fix writing to wrong PCI config registers after alignment arm64: hyp-stub: Forbid kprobing of the hyp-stub gfs2: Revert "Fix loop in gfs2_rbm_find" platform/x86: asus-nb-wmi: Map 0x35 to KEY_SCREENLOCK platform/x86: asus-nb-wmi: Drop mapping of 0x33 and 0x34 scan codes mmc: sdhci-iproc: handle mmc_of_parse() errors during probe kernel/exit.c: release ptraced tasks before zap_pid_ns_processes mm, oom: fix use-after-free in oom_kill_process cifs: Always resolve hostname before reconnecting drivers: core: Remove glue dirs from sysfs earlier mm: migrate: don't rely on __PageMovable() of newpage after unlocking it fs: don't scan the inode cache before SB_BORN is set Linux 4.4.173 Change-Id: Ifc01c8b56016e9145bb67258f91dfc6b6983354c Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
| | * fs: don't scan the inode cache before SB_BORN is setDave Chinner2019-02-06
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 79f546a696bff2590169fb5684e23d65f4d9f591 upstream. We recently had an oops reported on a 4.14 kernel in xfs_reclaim_inodes_count() where sb->s_fs_info pointed to garbage and so the m_perag_tree lookup walked into lala land. It produces an oops down this path during the failed mount: radix_tree_gang_lookup_tag+0xc4/0x130 xfs_perag_get_tag+0x37/0xf0 xfs_reclaim_inodes_count+0x32/0x40 xfs_fs_nr_cached_objects+0x11/0x20 super_cache_count+0x35/0xc0 shrink_slab.part.66+0xb1/0x370 shrink_node+0x7e/0x1a0 try_to_free_pages+0x199/0x470 __alloc_pages_slowpath+0x3a1/0xd20 __alloc_pages_nodemask+0x1c3/0x200 cache_grow_begin+0x20b/0x2e0 fallback_alloc+0x160/0x200 kmem_cache_alloc+0x111/0x4e0 The problem is that the superblock shrinker is running before the filesystem structures it depends on have been fully set up. i.e. the shrinker is registered in sget(), before ->fill_super() has been called, and the shrinker can call into the filesystem before fill_super() does it's setup work. Essentially we are exposed to both use-after-free and use-before-initialisation bugs here. To fix this, add a check for the SB_BORN flag in super_cache_count. In general, this flag is not set until ->fs_mount() completes successfully, so we know that it is set after the filesystem setup has completed. This matches the trylock_super() behaviour which will not let super_cache_scan() run if SB_BORN is not set, and hence will not allow the superblock shrinker from entering the filesystem while it is being set up or after it has failed setup and is being torn down. Cc: stable@kernel.org Signed-Off-By: Dave Chinner <dchinner@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Aaron Lu <aaron.lu@linux.alibaba.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* | | Merge android-4.4.120 (d63fdf6) into msm-4.4Srinivasarao P2018-03-08
|\| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * refs/heads/tmp-d63fdf6 Linux 4.4.120 MIPS: Implement __multi3 for GCC7 MIPS64r6 builds net: gianfar_ptp: move set_fipers() to spinlock protecting area sctp: make use of pre-calculated len xen/gntdev: Fix partial gntdev_mmap() cleanup xen/gntdev: Fix off-by-one error when unmapping with holes SolutionEngine771x: fix Ether platform data mdio-sun4i: Fix a memory leak xen-netfront: enable device after manual module load bnxt_en: Fix the 'Invalid VF' id check in bnxt_vf_ndo_prep routine. can: flex_can: Correct the checking for frame length in flexcan_start_xmit() mac80211: mesh: drop frames appearing to be from us drm/ttm: check the return value of kzalloc e1000: fix disabling already-disabled warning xfs: quota: check result of register_shrinker() xfs: quota: fix missed destroy of qi_tree_lock IB/ipoib: Fix race condition in neigh creation IB/mlx4: Fix mlx4_ib_alloc_mr error flow s390/dasd: fix wrongly assigned configuration data led: core: Fix brightness setting when setting delay_off=0 bnx2x: Improve reliability in case of nested PCI errors tg3: Enable PHY reset in MTU change path for 5720 tg3: Add workaround to restrict 5762 MRRS to 2048 lib/mpi: Fix umul_ppmm() for MIPS64r6 ARM: dts: ls1021a: fix incorrect clock references scsi: storvsc: Fix scsi_cmd error assignments in storvsc_handle_error net: arc_emac: fix arc_emac_rx() error paths spi: atmel: fixed spin_lock usage inside atmel_spi_remove drm/nouveau/pci: do a msi rearm on init sget(): handle failures of register_shrinker() ARM: 8731/1: Fix csum_partial_copy_from_user() stack mismatch ipv6: icmp6: Allow icmp messages to be looped back mtd: nand: gpmi: Fix failure when a erased page has a bitflip at BBM f2fs: fix a bug caused by NULL extent tree hrtimer: Ensure POSIX compliance (relative CLOCK_REALTIME hrtimers) ANDROID: keychord: Check for write data size Revert "binder: add missing binder_unlock()" Linux 4.4.119 binder: add missing binder_unlock() drm/amdgpu: Avoid leaking PM domain on driver unbind (v2) usb: renesas_usbhs: missed the "running" flag in usb_dmac with rx path usb: gadget: f_fs: Process all descriptors during bind usb: ldusb: add PIDs for new CASSY devices supported by this driver usb: dwc3: gadget: Set maxpacket size for ep0 IN drm/edid: Add 6 bpc quirk for CPT panel in Asus UX303LA Add delay-init quirk for Corsair K70 RGB keyboards arm64: Disable unhandled signal log messages by default usb: ohci: Proper handling of ed_rm_list to handle race condition between usb_kill_urb() and finish_unlinks() irqchip/gic-v3: Use wmb() instead of smb_wmb() in gic_raise_softirq() x86/oprofile: Fix bogus GCC-8 warning in nmi_setup() iio: adis_lib: Initialize trigger before requesting interrupt iio: buffer: check if a buffer has been set up when poll is called cfg80211: fix cfg80211_beacon_dup scsi: ibmvfc: fix misdefined reserved field in ibmvfc_fcp_rsp_info ip_tunnel: fix preempt warning in ip tunnel creation/updating ip_tunnel: replace dst_cache with generic implementation PCI: keystone: Fix interrupt-controller-node lookup powerpc/64s: Fix RFI flush dependency on HARDLOCKUP_DETECTOR netfilter: drop outermost socket lock in getsockopt() ANDROID: sdcardfs: Set num in extension_details during make_item Conflicts: drivers/usb/gadget/function/f_fs.c Change-Id: I594b9686fd64d4b62ebef4452d4f1ccca4f5a77b Signed-off-by: Srinivasarao P <spathi@codeaurora.org>
| * | Merge 4.4.120 into android-4.4Greg Kroah-Hartman2018-03-06
| |\| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Changes in 4.4.120 hrtimer: Ensure POSIX compliance (relative CLOCK_REALTIME hrtimers) f2fs: fix a bug caused by NULL extent tree mtd: nand: gpmi: Fix failure when a erased page has a bitflip at BBM ipv6: icmp6: Allow icmp messages to be looped back ARM: 8731/1: Fix csum_partial_copy_from_user() stack mismatch sget(): handle failures of register_shrinker() drm/nouveau/pci: do a msi rearm on init spi: atmel: fixed spin_lock usage inside atmel_spi_remove net: arc_emac: fix arc_emac_rx() error paths scsi: storvsc: Fix scsi_cmd error assignments in storvsc_handle_error ARM: dts: ls1021a: fix incorrect clock references lib/mpi: Fix umul_ppmm() for MIPS64r6 tg3: Add workaround to restrict 5762 MRRS to 2048 tg3: Enable PHY reset in MTU change path for 5720 bnx2x: Improve reliability in case of nested PCI errors led: core: Fix brightness setting when setting delay_off=0 s390/dasd: fix wrongly assigned configuration data IB/mlx4: Fix mlx4_ib_alloc_mr error flow IB/ipoib: Fix race condition in neigh creation xfs: quota: fix missed destroy of qi_tree_lock xfs: quota: check result of register_shrinker() e1000: fix disabling already-disabled warning drm/ttm: check the return value of kzalloc mac80211: mesh: drop frames appearing to be from us can: flex_can: Correct the checking for frame length in flexcan_start_xmit() bnxt_en: Fix the 'Invalid VF' id check in bnxt_vf_ndo_prep routine. xen-netfront: enable device after manual module load mdio-sun4i: Fix a memory leak SolutionEngine771x: fix Ether platform data xen/gntdev: Fix off-by-one error when unmapping with holes xen/gntdev: Fix partial gntdev_mmap() cleanup sctp: make use of pre-calculated len net: gianfar_ptp: move set_fipers() to spinlock protecting area MIPS: Implement __multi3 for GCC7 MIPS64r6 builds Linux 4.4.120 Change-Id: Ie363d2e798f7bbe76e728c995e605af94667dfe5 Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
| | * sget(): handle failures of register_shrinker()Al Viro2018-03-03
| | | | | | | | | | | | | | | | | | | | | | | | [ Upstream commit 9ee332d99e4d5a97548943b81c54668450ce641b ] Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Sasha Levin <alexander.levin@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * | Merge remote-tracking branch 'common/android-4.4' into android-4.4.yDmitry Shmidt2017-02-15
| |\ \ | | | | | | | | | | | | Change-Id: Icf907f5067fb6da5935ab0d3271df54b8d5df405
| | * | ANDROID: vfs: Allow filesystems to access their private mount dataDaniel Rosenberg2017-01-26
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Now we pass the vfsmount when mounting and remounting. This allows the filesystem to actually set up the mount specific data, although we can't quite do anything with it yet. show_options is expanded to include data that lives with the mount. To avoid changing existing filesystems, these have been added as new vfs functions. Change-Id: If80670bfad9f287abb8ac22457e1b034c9697097 Signed-off-by: Daniel Rosenberg <drosen@google.com>
| * | | Merge tag 'v4.4.28' into android-4.4.yDmitry Shmidt2016-10-28
| |\ \ \ | | | |/ | | |/| | | | | This is the 4.4.28 stable release
| * | | Merge tag 'v4.4.16' into android-4.4.yDmitry Shmidt2016-08-01
| |\ \ \ | | |_|/ | |/| | | | | | | | | | | | | | This is the 4.4.16 stable release Change-Id: Ibaf7b7e03695e1acebc654a2ca1a4bfcc48fcea4
* | | | block: Use pointer to backing_dev_info from request_queueJan Kara2017-10-18
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We will want to have struct backing_dev_info allocated separately from struct request_queue. As the first step add pointer to backing_dev_info to request_queue and convert all users touching it. No functional changes in this patch. Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Jens Axboe <axboe@fb.com> Change-Id: I77fbb181de7e39c83fbfba8cfb128d6ace161f31 Git-repo: git://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux-block.git Git-commit: 97419acd22a0bacc52dbc34d5bbc96d315e48acb [riteshh@codeaurora.org: resolved merge conflicts] Signed-off-by: Ritesh Harjani <riteshh@codeaurora.org>
* | | | ANDROID: vfs: Allow filesystems to access their private mount dataDaniel Rosenberg2017-02-03
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Now we pass the vfsmount when mounting and remounting. This allows the filesystem to actually set up the mount specific data, although we can't quite do anything with it yet. show_options is expanded to include data that lives with the mount. To avoid changing existing filesystems, these have been added as new vfs functions. Change-Id: If80670bfad9f287abb8ac22457e1b034c9697097 Signed-off-by: Daniel Rosenberg <drosen@google.com>
* | | | Merge branch 'linux-linaro-lsk-v4.4' into linux-linaro-lsk-v4.4-androidAlex Shi2016-10-29
|\ \ \ \ | | |_|/ | |/| |
| * | | fs/super.c: fix race between freeze_super() and thaw_super()Oleg Nesterov2016-10-28
| | |/ | |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 89f39af129382a40d7cd1f6914617282cfeee28e upstream. Change thaw_super() to check frozen != SB_FREEZE_COMPLETE rather than frozen == SB_UNFROZEN, otherwise it can race with freeze_super() which drops sb->s_umount after SB_FREEZE_WRITE to preserve the lock ordering. In this case thaw_super() will wrongly call s_op->unfreeze_fs() before it was actually frozen, and call sb_freeze_unlock() which leads to the unbalanced percpu_up_write(). Unfortunately lockdep can't detect this, so this triggers misc BUG_ON()'s in kernel/rcu/sync.c. Reported-and-tested-by: Nikolay Borisov <kernel@kyup.com> Signed-off-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* | | Merge branch 'linux-linaro-lsk-v4.4' into linux-linaro-lsk-v4.4-androidAlex Shi2016-03-14
|\| | | |/ |/| | | | | | | Conflicts solution: keep 'KBUILD_CFLAGS += -fno-pic' in arch/arm64/Makefile
| * writeback: flush inode cgroup wb switches instead of pinning super_blockTejun Heo2016-03-09
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit a1a0e23e49037c23ea84bc8cc146a03584d13577 upstream. If cgroup writeback is in use, inodes can be scheduled for asynchronous wb switching. Before 5ff8eaac1636 ("writeback: keep superblock pinned during cgroup writeback association switches"), this could race with umount leading to super_block being destroyed while inodes are pinned for wb switching. 5ff8eaac1636 fixed it by bumping s_active while wb switches are in flight; however, this allowed in-flight wb switches to make umounts asynchronous when the userland expected synchronosity - e.g. fsck immediately following umount may fail because the device is still busy. This patch removes the problematic super_block pinning and instead makes generic_shutdown_super() flush in-flight wb switches. wb switches are now executed on a dedicated isw_wq so that they can be flushed and isw_nr_in_flight keeps track of the number of in-flight wb switches so that flushing can be avoided in most cases. v2: Move cgroup_writeback_umount() further below and add MS_ACTIVE check in inode_switch_wbs() as Jan an Al suggested. Signed-off-by: Tejun Heo <tj@kernel.org> Reported-by: Tahsin Erdogan <tahsin@google.com> Cc: Jan Kara <jack@suse.cz> Cc: Al Viro <viro@ZenIV.linux.org.uk> Link: http://lkml.kernel.org/g/CAAeU0aNCq7LGODvVGRU-oU_o-6enii5ey0p1c26D1ZzYwkDc5A@mail.gmail.com Fixes: 5ff8eaac1636 ("writeback: keep superblock pinned during cgroup writeback association switches") Reviewed-by: Jan Kara <jack@suse.cz> Tested-by: Tahsin Erdogan <tahsin@google.com> Signed-off-by: Jens Axboe <axboe@fb.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* | Fix for in kernel emergency remount when loop mounts are usedChristian Poetzsch2016-02-16
|/ | | | | | | | | | | | | | | | | | | | | | | adb reboot calls /proc/sysrq-trigger to force an emergency remount (ro) of all mounted disks. This is executed in the order of the time the mount was originally done. Because we have a test system which loop mount images from an extra partition, we see errors cause the loop mounted partitions gets remounted after this physical partition was set to read only already. Fix this by reversing the order of the emergency remount. This will remount the disk first which have been mounted last. So instead of remounting in this order: /dev/sda1 /dev/loop1 /dev/loop2 we now remount in this order: /dev/loop2 /dev/loop1 /dev/sda1 Change-Id: I68fe7e16cc9400ab5278877af70c9ea1d9b57936 Signed-off-by: Christian Poetzsch <christian.potzsch@imgtec.com>
* Merge branch 'superblock-scaling' of ↵Al Viro2015-08-21
|\ | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/josef/btrfs-next into for-next Conflicts: include/linux/fs.h
| * sync: serialise per-superblock sync operationsDave Chinner2015-08-17
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When competing sync(2) calls walk the same filesystem, they need to walk the list of inodes on the superblock to find all the inodes that we need to wait for IO completion on. However, when multiple wait_sb_inodes() calls do this at the same time, they contend on the the inode_sb_list_lock and the contention causes system wide slowdowns. In effect, concurrent sync(2) calls can take longer and burn more CPU than if they were serialised. Stop the worst of the contention by adding a per-sb mutex to wrap around wait_sb_inodes() so that we only execute one sync(2) IO completion walk per superblock superblock at a time and hence avoid contention being triggered by concurrent sync(2) calls. Signed-off-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Josef Bacik <jbacik@fb.com> Reviewed-by: Jan Kara <jack@suse.cz> Reviewed-by: Christoph Hellwig <hch@lst.de> Tested-by: Dave Chinner <dchinner@redhat.com>
| * inode: convert inode_sb_list_lock to per-sbDave Chinner2015-08-17
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The process of reducing contention on per-superblock inode lists starts with moving the locking to match the per-superblock inode list. This takes the global lock out of the picture and reduces the contention problems to within a single filesystem. This doesn't get rid of contention as the locks still have global CPU scope, but it does isolate operations on different superblocks form each other. Signed-off-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Josef Bacik <jbacik@fb.com> Reviewed-by: Jan Kara <jack@suse.cz> Reviewed-by: Christoph Hellwig <hch@lst.de> Tested-by: Dave Chinner <dchinner@redhat.com>
* | change sb_writers to use percpu_rw_semaphoreOleg Nesterov2015-08-15
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We can remove everything from struct sb_writers except frozen and add the array of percpu_rw_semaphore's instead. This patch doesn't remove sb_writers->wait_unfrozen yet, we keep it for get_super_thawed(). We will probably remove it later. This change tries to address the following problems: - Firstly, __sb_start_write() looks simply buggy. It does __sb_end_write() if it sees ->frozen, but if it migrates to another CPU before percpu_counter_dec(), sb_wait_write() can wrongly succeed if there is another task which holds the same "semaphore": sb_wait_write() can miss the result of the previous percpu_counter_inc() but see the result of this percpu_counter_dec(). - As Dave Hansen reports, it is suboptimal. The trivial microbenchmark that writes to a tmpfs file in a loop runs 12% faster if we change this code to rely on RCU and kill the memory barriers. - This code doesn't look simple. It would be better to rely on the generic locking code. According to Dave, this change adds the same performance improvement. Note: with this change both freeze_super() and thaw_super() will do synchronize_sched_expedited() 3 times. This is just ugly. But: - This will be "fixed" by the rcu_sync changes we are going to merge. After that freeze_super()->percpu_down_write() will use synchronize_sched(), and thaw_super() won't use synchronize() at all. This doesn't need any changes in fs/super.c. - Once we merge rcu_sync changes, we can also change super.c so that all wb_write->rw_sem's will share the single ->rss in struct sb_writes, then freeze_super() will need only one synchronize_sched(). Signed-off-by: Oleg Nesterov <oleg@redhat.com> Reviewed-by: Jan Kara <jack@suse.com>
* | shift percpu_counter_destroy() into destroy_super_work()Oleg Nesterov2015-08-15
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Of course, this patch is ugly as hell. It will be (partially) reverted later. We add it to ensure that other WIP changes in percpu_rw_semaphore won't break fs/super.c. We do not even need this change right now, percpu_free_rwsem() is fine in atomic context. But we are going to change this, it will be might_sleep() after we merge the rcu_sync() patches. And even after that we do not really need destroy_super_work(), we will kill it in any case. Instead, destroy_super_rcu() should just check that rss->cb_state == CB_IDLE and do call_rcu() again in the (very unlikely) case this is not true. So this is just the temporary kludge which helps us to avoid the conflicts with the changes which will be (hopefully) routed via rcu tree. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Reviewed-by: Jan Kara <jack@suse.com>
* | document rwsem_release() in sb_wait_write()Oleg Nesterov2015-08-15
| | | | | | | | | | | | | | | | | | | | | | Not only we need to avoid the warning from lockdep_sys_exit(), the caller of freeze_super() can never release this lock. Another thread can do this, so there is another reason for rwsem_release(). Plus the comment should explain why we have to fool lockdep. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Reviewed-by: Jan Kara <jack@suse.com>
* | fix the broken lockdep logic in __sb_start_write()Oleg Nesterov2015-08-15
|/ | | | | | | | | | | | | | | | | | | | | | | | | 1. wait_event(frozen < level) without rwsem_acquire_read() is just wrong from lockdep perspective. If we are going to deadlock because the caller is buggy, lockdep can't detect this problem. 2. __sb_start_write() can race with thaw_super() + freeze_super(), and after "goto retry" the 2nd acquire_freeze_lock() is wrong. 3. The "tell lockdep we are doing trylock" hack doesn't look nice. I think this is correct, but this logic should be more explicit. Yes, the recursive read_lock() is fine if we hold the lock on a higher level. But we do not need to fool lockdep. If we can not deadlock in this case then try-lock must not fail and we can use use wait == F throughout this code. Note: as Dave Chinner explains, the "trylock" hack and the fat comment can be probably removed. But this needs a separate change and it will be trivial: just kill __sb_start_write() and rename do_sb_start_write() back to __sb_start_write(). Signed-off-by: Oleg Nesterov <oleg@redhat.com> Reviewed-by: Jan Kara <jack@suse.com>
* fs:super:get_anon_bdev: fix race condition could cause dev exceed its upper ↵Wang YanQing2015-07-01
| | | | | | | | | | | | | limitation Execution of get_anon_bdev concurrently and preemptive kernel all could bring race condition, it isn't enough to check dev against its upper limitation with equality operator only. This patch fix it. Signed-off-by: Wang YanQing <udknight@gmail.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* cleancache: remove limit on the number of cleancache enabled filesystemsVladimir Davydov2015-04-14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The limit equals 32 and is imposed by the number of entries in the fs_poolid_map and shared_fs_poolid_map. Nowadays it is insufficient, because with containers on board a Linux host can have hundreds of active fs mounts. These maps were introduced by commit 49a9ab815acb8 ("mm: cleancache: lazy initialization to allow tmem backends to build/run as modules") in order to allow compiling cleancache drivers as modules. Real pool ids are stored in these maps while super_block->cleancache_poolid points to an entry in the map, so that on cleancache registration we can walk over all (if there are <= 32 of them, of course) cleancache-enabled super blocks and assign real pool ids. Actually, there is absolutely no need in these maps, because we can iterate over all super blocks immediately using iterate_supers. This is not racy, because cleancache_init_ops is called from mount_fs with super_block->s_umount held for writing, while iterate_supers takes this semaphore for reading, so if we call iterate_supers after setting cleancache_ops, all super blocks that had been created before cleancache_register_ops was called will be assigned pool ids by the action function of iterate_supers while all newer super blocks will receive it in cleancache_init_fs. This patch therefore removes the maps and hence the artificial limit on the number of cleancache enabled filesystems. Signed-off-by: Vladimir Davydov <vdavydov@parallels.com> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: David Vrabel <david.vrabel@citrix.com> Cc: Mark Fasheh <mfasheh@suse.com> Cc: Joel Becker <jlbec@evilplan.org> Cc: Stefan Hengelein <ilendir@googlemail.com> Cc: Florian Schmaus <fschmaus@gmail.com> Cc: Andor Daam <andor.daam@googlemail.com> Cc: Dan Magenheimer <dan.magenheimer@oracle.com> Cc: Bob Liu <lliubbo@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* trylock_super(): replacement for grab_super_passive()Konstantin Khlebnikov2015-02-22
| | | | | | | | | | | | | | | | | | | | | | | | | I've noticed significant locking contention in memory reclaimer around sb_lock inside grab_super_passive(). Grab_super_passive() is called from two places: in icache/dcache shrinkers (function super_cache_scan) and from writeback (function __writeback_inodes_wb). Both are required for progress in memory allocator. Grab_super_passive() acquires sb_lock to increment sb->s_count and check sb->s_instances. It seems sb->s_umount locked for read is enough here: super-block deactivation always runs under sb->s_umount locked for write. Protecting super-block itself isn't a problem: in super_cache_scan() sb is protected by shrinker_rwsem: it cannot be freed if its slab shrinkers are still active. Inside writeback super-block comes from inode from bdi writeback list under wb->list_lock. This patch removes locking sb_lock and checks s_instances under s_umount: generic_shutdown_super() unlinks it under sb->s_umount locked for write. New variant is called trylock_super() and since it only locks semaphore, callers must call up_read(&sb->s_umount) instead of drop_super(sb) when they're done. Signed-off-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* Merge branch 'for-linus' of ↵Linus Torvalds2015-02-17
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull misc VFS updates from Al Viro: "This cycle a lot of stuff sits on topical branches, so I'll be sending more or less one pull request per branch. This is the first pile; more to follow in a few. In this one are several misc commits from early in the cycle (before I went for separate branches), plus the rework of mntput/dput ordering on umount, switching to use of fs_pin instead of convoluted games in namespace_unlock()" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: switch the IO-triggering parts of umount to fs_pin new fs_pin killing logics allow attaching fs_pin to a group not associated with some superblock get rid of the second argument of acct_kill() take count and rcu_head out of fs_pin dcache: let the dentry count go down to zero without taking d_lock pull bumping refcount into ->kill() kill pin_put() mode_t whack-a-mole: chelsio file->f_path.dentry is pinned down for as long as the file is open... get rid of lustre_dump_dentry() gut proc_register() a bit kill d_validate() ncpfs: get rid of d_validate() nonsense selinuxfs: don't open-code d_genocide()
| * allow attaching fs_pin to a group not associated with some superblockAl Viro2015-01-25
| | | | | | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* | Merge branch 'akpm' (patches from Andrew)Linus Torvalds2015-02-12
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Merge third set of updates from Andrew Morton: - the rest of MM [ This includes getting rid of the numa hinting bits, in favor of just generic protnone logic. Yay. - Linus ] - core kernel - procfs - some of lib/ (lots of lib/ material this time) * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (104 commits) lib/lcm.c: replace include lib/percpu_ida.c: remove redundant includes lib/strncpy_from_user.c: replace module.h include lib/stmp_device.c: replace module.h include lib/sort.c: move include inside #if 0 lib/show_mem.c: remove redundant include lib/radix-tree.c: change to simpler include lib/plist.c: remove redundant include lib/nlattr.c: remove redundant include lib/kobject_uevent.c: remove redundant include lib/llist.c: remove redundant include lib/md5.c: simplify include lib/list_sort.c: rearrange includes lib/genalloc.c: remove redundant include lib/idr.c: remove redundant include lib/halfmd4.c: simplify includes lib/dynamic_queue_limits.c: simplify includes lib/sort.c: use simpler includes lib/interval_tree.c: simplify includes hexdump: make it return number of bytes placed in buffer ...
| * | fs: shrinker: always scan at least one object of each typeVladimir Davydov2015-02-12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In super_cache_scan() we divide the number of objects of particular type by the total number of objects in order to distribute pressure among As a result, in some corner cases we can get nr_to_scan=0 even if there are some objects to reclaim, e.g. dentries=1, inodes=1, fs_objects=1, nr_to_scan=1/3=0. This is unacceptable for per memcg kmem accounting, because this means that some objects may never get reclaimed after memcg death, preventing it from being freed. This patch therefore assures that super_cache_scan() will scan at least one object of each type if any. [akpm@linux-foundation.org: add comment] Signed-off-by: Vladimir Davydov <vdavydov@parallels.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@suse.cz> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Dave Chinner <david@fromorbit.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * | fs: make shrinker memcg awareVladimir Davydov2015-02-12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Now, to make any list_lru-based shrinker memcg aware we should only initialize its list_lru as memcg aware. Let's do it for the general FS shrinker (super_block::s_shrink). There are other FS-specific shrinkers that use list_lru for storing objects, such as XFS and GFS2 dquot cache shrinkers, but since they reclaim objects that are shared among different cgroups, there is no point making them memcg aware. It's a big question whether we should account them to memcg at all. Signed-off-by: Vladimir Davydov <vdavydov@parallels.com> Cc: Dave Chinner <david@fromorbit.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@suse.cz> Cc: Greg Thelen <gthelen@google.com> Cc: Glauber Costa <glommer@gmail.com> 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> Cc: Tejun Heo <tj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * | list_lru: organize all list_lrus to listVladimir Davydov2015-02-12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | To make list_lru memcg aware, we need all list_lrus to be kept on a list protected by a mutex, so that we could sleep while walking over the list. Therefore after this change list_lru_destroy may sleep. Fortunately, there is only one user that calls it from an atomic context - it's put_super - and we can easily fix it by calling list_lru_destroy before put_super in destroy_locked_super - anyway we don't longer need lrus by that time. Another point that should be noted is that list_lru_destroy is allowed to be called on an uninitialized zeroed-out object, in which case it is a no-op. Before this patch this was guaranteed by kfree, but now we need an explicit check there. Signed-off-by: Vladimir Davydov <vdavydov@parallels.com> Cc: Dave Chinner <david@fromorbit.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@suse.cz> Cc: Greg Thelen <gthelen@google.com> Cc: Glauber Costa <glommer@gmail.com> 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> Cc: Tejun Heo <tj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * | fs: consolidate {nr,free}_cached_objects args in shrink_controlVladimir Davydov2015-02-12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We are going to make FS shrinkers memcg-aware. To achieve that, we will have to pass the memcg to scan to the nr_cached_objects and free_cached_objects VFS methods, which currently take only the NUMA node to scan. Since the shrink_control structure already holds the node, and the memcg to scan will be added to it when we introduce memcg-aware vmscan, let us consolidate the methods' arguments in this structure to keep things clean. Signed-off-by: Vladimir Davydov <vdavydov@parallels.com> Suggested-by: Dave Chinner <david@fromorbit.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@suse.cz> Cc: Greg Thelen <gthelen@google.com> Cc: Glauber Costa <glommer@gmail.com> 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> Cc: Tejun Heo <tj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * | list_lru: introduce list_lru_shrink_{count,walk}Vladimir Davydov2015-02-12
| |/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Kmem accounting of memcg is unusable now, because it lacks slab shrinker support. That means when we hit the limit we will get ENOMEM w/o any chance to recover. What we should do then is to call shrink_slab, which would reclaim old inode/dentry caches from this cgroup. This is what this patch set is intended to do. Basically, it does two things. First, it introduces the notion of per-memcg slab shrinker. A shrinker that wants to reclaim objects per cgroup should mark itself as SHRINKER_MEMCG_AWARE. Then it will be passed the memory cgroup to scan from in shrink_control->memcg. For such shrinkers shrink_slab iterates over the whole cgroup subtree under the target cgroup and calls the shrinker for each kmem-active memory cgroup. Secondly, this patch set makes the list_lru structure per-memcg. It's done transparently to list_lru users - everything they have to do is to tell list_lru_init that they want memcg-aware list_lru. Then the list_lru will automatically distribute objects among per-memcg lists basing on which cgroup the object is accounted to. This way to make FS shrinkers (icache, dcache) memcg-aware we only need to make them use memcg-aware list_lru, and this is what this patch set does. As before, this patch set only enables per-memcg kmem reclaim when the pressure goes from memory.limit, not from memory.kmem.limit. Handling memory.kmem.limit is going to be tricky due to GFP_NOFS allocations, and it is still unclear whether we will have this knob in the unified hierarchy. This patch (of 9): NUMA aware slab shrinkers use the list_lru structure to distribute objects coming from different NUMA nodes to different lists. Whenever such a shrinker needs to count or scan objects from a particular node, it issues commands like this: count = list_lru_count_node(lru, sc->nid); freed = list_lru_walk_node(lru, sc->nid, isolate_func, isolate_arg, &sc->nr_to_scan); where sc is an instance of the shrink_control structure passed to it from vmscan. To simplify this, let's add special list_lru functions to be used by shrinkers, list_lru_shrink_count() and list_lru_shrink_walk(), which consolidate the nid and nr_to_scan arguments in the shrink_control structure. This will also allow us to avoid patching shrinkers that use list_lru when we make shrink_slab() per-memcg - all we will have to do is extend the shrink_control structure to include the target memcg and make list_lru_shrink_{count,walk} handle this appropriately. Signed-off-by: Vladimir Davydov <vdavydov@parallels.com> Suggested-by: Dave Chinner <david@fromorbit.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@suse.cz> Cc: Greg Thelen <gthelen@google.com> Cc: Glauber Costa <glommer@gmail.com> 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> Cc: Tejun Heo <tj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | Make super_blocks and sb_lock staticAl Viro2015-02-02
| | | | | | | | | | | | | | | | The only user outside of fs/super.c is gone now Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Acked-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@fb.com>
* | fs: remove default_backing_dev_infoChristoph Hellwig2015-01-20
|/ | | | | | | | | | | | | | | | | | Now that default_backing_dev_info is not used for writeback purposes we can git rid of it easily: - instead of using it's name for tracing unregistered bdi we just use "unknown" - btrfs and ceph can just assign the default read ahead window themselves like several other filesystems already do. - we can assign noop_backing_dev_info as the default one in alloc_super. All filesystems already either assigned their own or noop_backing_dev_info. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Tejun Heo <tj@kernel.org> Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: Jens Axboe <axboe@fb.com>
* Merge branch 'for-linus' of ↵Linus Torvalds2014-10-13
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull vfs updates from Al Viro: "The big thing in this pile is Eric's unmount-on-rmdir series; we finally have everything we need for that. The final piece of prereqs is delayed mntput() - now filesystem shutdown always happens on shallow stack. Other than that, we have several new primitives for iov_iter (Matt Wilcox, culled from his XIP-related series) pushing the conversion to ->read_iter()/ ->write_iter() a bit more, a bunch of fs/dcache.c cleanups and fixes (including the external name refcounting, which gives consistent behaviour of d_move() wrt procfs symlinks for long and short names alike) and assorted cleanups and fixes all over the place. This is just the first pile; there's a lot of stuff from various people that ought to go in this window. Starting with unionmount/overlayfs mess... ;-/" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (60 commits) fs/file_table.c: Update alloc_file() comment vfs: Deduplicate code shared by xattr system calls operating on paths reiserfs: remove pointless forward declaration of struct nameidata don't need that forward declaration of struct nameidata in dcache.h anymore take dname_external() into fs/dcache.c let path_init() failures treated the same way as subsequent link_path_walk() fix misuses of f_count() in ppp and netlink ncpfs: use list_for_each_entry() for d_subdirs walk vfs: move getname() from callers to do_mount() gfs2_atomic_open(): skip lookups on hashed dentry [infiniband] remove pointless assignments gadgetfs: saner API for gadgetfs_create_file() f_fs: saner API for ffs_sb_create_file() jfs: don't hash direct inode [s390] remove pointless assignment of ->f_op in vmlogrdr ->open() ecryptfs: ->f_op is never NULL android: ->f_op is never NULL nouveau: __iomem misannotations missing annotation in fs/file.c fs: namespace: suppress 'may be used uninitialized' warnings ...
| * fs: Fix theoretical division by 0 in super_cache_scan().Tetsuo Handa2014-10-09
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | total_objects could be 0 and is used as a denom. While total_objects is a "long", total_objects == 0 unlikely happens for 3.12 and later kernels because 32-bit architectures would not be able to hold (1 << 32) objects. However, total_objects == 0 may happen for kernels between 3.1 and 3.11 because total_objects in prune_super() was an "int" and (e.g.) x86_64 architecture might be able to hold (1 << 32) objects. Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Reviewed-by: Christoph Hellwig <hch@lst.de> Cc: stable <stable@kernel.org> # 3.1+ Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* | percpu_counter: add @gfp to percpu_counter_init()Tejun Heo2014-09-08
|/ | | | | | | | | | | | | | | | | | | | | | | | Percpu allocator now supports allocation mask. Add @gfp to percpu_counter_init() so that !GFP_KERNEL allocation masks can be used with percpu_counters too. We could have left percpu_counter_init() alone and added percpu_counter_init_gfp(); however, the number of users isn't that high and introducing _gfp variants to all percpu data structures would be quite ugly, so let's just do the conversion. This is the one with the most users. Other percpu data structures are a lot easier to convert. This patch doesn't make any functional difference. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Jan Kara <jack@suse.cz> Acked-by: "David S. Miller" <davem@davemloft.net> Cc: x86@kernel.org Cc: Jens Axboe <axboe@kernel.dk> Cc: "Theodore Ts'o" <tytso@mit.edu> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Andrew Morton <akpm@linux-foundation.org>
* Merge branch 'for_linus' of ↵Linus Torvalds2014-08-13
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs Pull quota, reiserfs, UDF updates from Jan Kara: "Scalability improvements for quota, a few reiserfs fixes, and couple of misc cleanups (udf, ext2)" * 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs: reiserfs: Fix use after free in journal teardown reiserfs: fix corruption introduced by balance_leaf refactor udf: avoid redundant memcpy when writing data in ICB fs/udf: re-use hex_asc_upper_{hi,lo} macros fs/quota: kernel-doc warning fixes udf: use linux/uaccess.h fs/ext2/super.c: Drop memory allocation cast quota: remove dqptr_sem quota: simplify remove_inode_dquot_ref() quota: avoid unnecessary dqget()/dqput() calls quota: protect Q_GETFMT by dqonoff_mutex
| * quota: remove dqptr_semNiu Yawei2014-07-15
| | | | | | | | | | | | | | | | | | | | Remove dqptr_sem to make quota code scalable: Remove the dqptr_sem, accessing inode->i_dquot now protected by dquot_srcu, and changing inode->i_dquot is now serialized by dq_data_lock. Signed-off-by: Lai Siyao <lai.siyao@intel.com> Signed-off-by: Niu Yawei <yawei.niu@intel.com> Signed-off-by: Jan Kara <jack@suse.cz>
* | make fs/{namespace,super}.c forget about acct.hAl Viro2014-08-07
| | | | | | | | | | | | | | These externs belong in fs/internal.h. Rename (they are not acct-specific anymore) and move them over there. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* | drop ->s_umount around acct_auto_close()Al Viro2014-08-07
| | | | | | | | | | | | | | | | | | | | just repeat the frozen check after regaining it, and check that sb is still alive. If several threads hit acct_auto_close() at the same time, acct_auto_close() will survive that just fine. And we really don't want to play with writes and closing the file with ->s_umount held exclusive - it's a deadlock country. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* | acct: get rid of acct_listAl Viro2014-08-07
|/ | | | | | | | Put these suckers on per-vfsmount and per-superblock lists instead. Note: right now it's still acct_lock for everything, but that's going to change. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* fs/superblock: avoid locking counting inodes and dentries before reclaiming themTim Chen2014-06-04
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We remove the call to grab_super_passive in call to super_cache_count. This becomes a scalability bottleneck as multiple threads are trying to do memory reclamation, e.g. when we are doing large amount of file read and page cache is under pressure. The cached objects quickly got reclaimed down to 0 and we are aborting the cache_scan() reclaim. But counting creates a log jam acquiring the sb_lock. We are holding the shrinker_rwsem which ensures the safety of call to list_lru_count_node() and s_op->nr_cached_objects. The shrinker is unregistered now before ->kill_sb() so the operation is safe when we are doing unmount. The impact will depend heavily on the machine and the workload but for a small machine using postmark tuned to use 4xRAM size the results were 3.15.0-rc5 3.15.0-rc5 vanilla shrinker-v1r1 Ops/sec Transactions 21.00 ( 0.00%) 24.00 ( 14.29%) Ops/sec FilesCreate 39.00 ( 0.00%) 44.00 ( 12.82%) Ops/sec CreateTransact 10.00 ( 0.00%) 12.00 ( 20.00%) Ops/sec FilesDeleted 6202.00 ( 0.00%) 6202.00 ( 0.00%) Ops/sec DeleteTransact 11.00 ( 0.00%) 12.00 ( 9.09%) Ops/sec DataRead/MB 25.97 ( 0.00%) 29.10 ( 12.05%) Ops/sec DataWrite/MB 49.99 ( 0.00%) 56.02 ( 12.06%) ffsb running in a configuration that is meant to simulate a mail server showed 3.15.0-rc5 3.15.0-rc5 vanilla shrinker-v1r1 Ops/sec readall 9402.63 ( 0.00%) 9567.97 ( 1.76%) Ops/sec create 4695.45 ( 0.00%) 4735.00 ( 0.84%) Ops/sec delete 173.72 ( 0.00%) 179.83 ( 3.52%) Ops/sec Transactions 14271.80 ( 0.00%) 14482.81 ( 1.48%) Ops/sec Read 37.00 ( 0.00%) 37.60 ( 1.62%) Ops/sec Write 18.20 ( 0.00%) 18.30 ( 0.55%) Signed-off-by: Tim Chen <tim.c.chen@linux.intel.com> Signed-off-by: Mel Gorman <mgorman@suse.de> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Hugh Dickins <hughd@google.com> Cc: Dave Chinner <david@fromorbit.com> Tested-by: Yuanhan Liu <yuanhan.liu@linux.intel.com> Cc: Bob Liu <bob.liu@oracle.com> Cc: Jan Kara <jack@suse.cz> Acked-by: Rik van Riel <riel@redhat.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>