Watch
1
Fork
You've already forked kernel_a52xq
0
mirror of https://github.com/a52xq-dev/kernel.git synced 2026-10-18 21:58:11 +07:00
Commit graph kernel_a52xq/fs/dcache.c
Message SHA1
treewide: import latest Galaxy A52 5G kernel
* this imports the latest version of SM-A526B kernel from https://opensource.samsung.com/uploadSearch?searchValue=SM-A526B

itsaschoolbus   commited 2026-09-27 19:03:59 +07:00
34794f4cb2
This is the 4.19.149 stable release
-----BEGIN PGP SIGNATURE-----
 
 iQIzBAABCAAdFiEEZH8oZUiU471FcZm+ONu9yGCSaT4FAl91ulMACgkQONu9yGCS
 aT7ezhAArTOQxPGkhktgdGfCMYgjvIHdny8o4pNGumnxW6TG7FCiJHoZuj8OLkdx
 2x5brOOvSGgcGTOwJXyUjL6opQzD5syTCuzbgEpGB2Tyd1x5q8vgqvI2XPxZeYHy
 x+mUDgacT+4m7FNbFDhNMZoTS4KCiJ3IcTevjeQexDtIs6R38HhxNl0Ee67gkqxZ
 p7c6L3kbUuR5T9EWGE1DPPLhOFGeOMk592qzkFsCGERsuswQOpXrxyw6zkik/0UG
 6Losmo2i+OtQFeiDz0WYJZNO9ySI511j+7R2Ewch/nFuTp6yFzy9kJZnP0YWK/KE
 U4BLmopgzCs9q+TQ/QNjxlCltl4eOrrjkFXF3Zz8o5ddbKwrugEsJUdUUDIpva71
 qEUgSw7vguGKoCttBenCDwyYOcjIVJRBFSWTVDzkgw5pXrz3m7qePF1Kj+KzG0pN
 8gTqosXPlYPzH1mh+2vRVntiCpZRMJYo18CX+ifqN20dHH3dsM4vA5NiWwjTJVY8
 JddRXfujxBQ0jxs2jFKvPZNrgqeY3Mh51L0a5G+HbHCIb+4kgD+2jl+C/X38TKch
 osTM1/qQriFVxtlH9TkTa8opYvrYBWO+G+XhNVc2tSpmd8T2EaKokMAVVvGiK3l9
 ZPq06SytJyKDPsSLvk4BKxCUv5CY0VT18k6mCYd1fq4oxTR92A4=
 =5bC5
 -----END PGP SIGNATURE-----

Merge 4.19.149 into android-4.19-stable

Changes in 4.19.149
	selinux: allow labeling before policy is loaded
	media: mc-device.c: fix memleak in media_device_register_entity
	dma-fence: Serialise signal enabling (dma_fence_enable_sw_signaling)
	ath10k: fix array out-of-bounds access
	ath10k: fix memory leak for tpc_stats_final
	mm: fix double page fault on arm64 if PTE_AF is cleared
	scsi: aacraid: fix illegal IO beyond last LBA
	m68k: q40: Fix info-leak in rtc_ioctl
	gma/gma500: fix a memory disclosure bug due to uninitialized bytes
	ASoC: kirkwood: fix IRQ error handling
	media: smiapp: Fix error handling at NVM reading
	arch/x86/lib/usercopy_64.c: fix __copy_user_flushcache() cache writeback
	x86/ioapic: Unbreak check_timer()
	ALSA: usb-audio: Add delay quirk for H570e USB headsets
	ALSA: hda/realtek - Couldn't detect Mic if booting with headset plugged
	ALSA: hda/realtek: Enable front panel headset LED on Lenovo ThinkStation P520
	lib/string.c: implement stpcpy
	leds: mlxreg: Fix possible buffer overflow
	PM / devfreq: tegra30: Fix integer overflow on CPU's freq max out
	scsi: fnic: fix use after free
	scsi: lpfc: Fix kernel crash at lpfc_nvme_info_show during remote port bounce
	net: silence data-races on sk_backlog.tail
	clk/ti/adpll: allocate room for terminating null
	drm/amdgpu/powerplay: fix AVFS handling with custom powerplay table
	mtd: cfi_cmdset_0002: don't free cfi->cfiq in error path of cfi_amdstd_setup()
	mfd: mfd-core: Protect against NULL call-back function pointer
	drm/amdgpu/powerplay/smu7: fix AVFS handling with custom powerplay table
	tpm_crb: fix fTPM on AMD Zen+ CPUs
	tracing: Adding NULL checks for trace_array descriptor pointer
	bcache: fix a lost wake-up problem caused by mca_cannibalize_lock
	dmaengine: mediatek: hsdma_probe: fixed a memory leak when devm_request_irq fails
	RDMA/qedr: Fix potential use after free
	RDMA/i40iw: Fix potential use after free
	fix dget_parent() fastpath race
	xfs: fix attr leaf header freemap.size underflow
	RDMA/iw_cgxb4: Fix an error handling path in 'c4iw_connect()'
	ubi: Fix producing anchor PEBs
	mmc: core: Fix size overflow for mmc partitions
	gfs2: clean up iopen glock mess in gfs2_create_inode
	scsi: pm80xx: Cleanup command when a reset times out
	debugfs: Fix !DEBUG_FS debugfs_create_automount
	CIFS: Properly process SMB3 lease breaks
	ASoC: max98090: remove msleep in PLL unlocked workaround
	kernel/sys.c: avoid copying possible padding bytes in copy_to_user
	KVM: arm/arm64: vgic: Fix potential double free dist->spis in __kvm_vgic_destroy()
	xfs: fix log reservation overflows when allocating large rt extents
	neigh_stat_seq_next() should increase position index
	rt_cpu_seq_next should increase position index
	ipv6_route_seq_next should increase position index
	seqlock: Require WRITE_ONCE surrounding raw_seqcount_barrier
	media: ti-vpe: cal: Restrict DMA to avoid memory corruption
	sctp: move trace_sctp_probe_path into sctp_outq_sack
	ACPI: EC: Reference count query handlers under lock
	scsi: ufs: Make ufshcd_add_command_trace() easier to read
	scsi: ufs: Fix a race condition in the tracing code
	dmaengine: zynqmp_dma: fix burst length configuration
	s390/cpum_sf: Use kzalloc and minor changes
	powerpc/eeh: Only dump stack once if an MMIO loop is detected
	Bluetooth: btrtl: Use kvmalloc for FW allocations
	tracing: Set kernel_stack's caller size properly
	ARM: 8948/1: Prevent OOB access in stacktrace
	ar5523: Add USB ID of SMCWUSBT-G2 wireless adapter
	ceph: ensure we have a new cap before continuing in fill_inode
	selftests/ftrace: fix glob selftest
	tools/power/x86/intel_pstate_tracer: changes for python 3 compatibility
	Bluetooth: Fix refcount use-after-free issue
	mm/swapfile.c: swap_next should increase position index
	mm: pagewalk: fix termination condition in walk_pte_range()
	Bluetooth: prefetch channel before killing sock
	KVM: fix overflow of zero page refcount with ksm running
	ALSA: hda: Clear RIRB status before reading WP
	skbuff: fix a data race in skb_queue_len()
	audit: CONFIG_CHANGE don't log internal bookkeeping as an event
	selinux: sel_avc_get_stat_idx should increase position index
	scsi: lpfc: Fix RQ buffer leakage when no IOCBs available
	scsi: lpfc: Fix coverity errors in fmdi attribute handling
	drm/omap: fix possible object reference leak
	clk: stratix10: use do_div() for 64-bit calculation
	crypto: chelsio - This fixes the kernel panic which occurs during a libkcapi test
	mt76: clear skb pointers from rx aggregation reorder buffer during cleanup
	ALSA: usb-audio: Don't create a mixer element with bogus volume range
	perf test: Fix test trace+probe_vfs_getname.sh on s390
	RDMA/rxe: Fix configuration of atomic queue pair attributes
	KVM: x86: fix incorrect comparison in trace event
	dmaengine: stm32-mdma: use vchan_terminate_vdesc() in .terminate_all
	media: staging/imx: Missing assignment in imx_media_capture_device_register()
	x86/pkeys: Add check for pkey "overflow"
	bpf: Remove recursion prevention from rcu free callback
	dmaengine: stm32-dma: use vchan_terminate_vdesc() in .terminate_all
	dmaengine: tegra-apb: Prevent race conditions on channel's freeing
	drm/amd/display: dal_ddc_i2c_payloads_create can fail causing panic
	firmware: arm_sdei: Use cpus_read_lock() to avoid races with cpuhp
	random: fix data races at timer_rand_state
	bus: hisi_lpc: Fixup IO ports addresses to avoid use-after-free in host removal
	media: go7007: Fix URB type for interrupt handling
	Bluetooth: guard against controllers sending zero'd events
	timekeeping: Prevent 32bit truncation in scale64_check_overflow()
	ext4: fix a data race at inode->i_disksize
	perf jevents: Fix leak of mapfile memory
	mm: avoid data corruption on CoW fault into PFN-mapped VMA
	drm/amdgpu: increase atombios cmd timeout
	drm/amd/display: Stop if retimer is not available
	ath10k: use kzalloc to read for ath10k_sdio_hif_diag_read
	scsi: aacraid: Disabling TM path and only processing IOP reset
	Bluetooth: L2CAP: handle l2cap config request during open state
	media: tda10071: fix unsigned sign extension overflow
	xfs: don't ever return a stale pointer from __xfs_dir3_free_read
	xfs: mark dir corrupt when lookup-by-hash fails
	ext4: mark block bitmap corrupted when found instead of BUGON
	tpm: ibmvtpm: Wait for buffer to be set before proceeding
	rtc: sa1100: fix possible race condition
	rtc: ds1374: fix possible race condition
	nfsd: Don't add locks to closed or closing open stateids
	RDMA/cm: Remove a race freeing timewait_info
	KVM: PPC: Book3S HV: Treat TM-related invalid form instructions on P9 like the valid ones
	drm/msm: fix leaks if initialization fails
	drm/msm/a5xx: Always set an OPP supported hardware value
	tracing: Use address-of operator on section symbols
	thermal: rcar_thermal: Handle probe error gracefully
	perf parse-events: Fix 3 use after frees found with clang ASAN
	serial: 8250_port: Don't service RX FIFO if throttled
	serial: 8250_omap: Fix sleeping function called from invalid context during probe
	serial: 8250: 8250_omap: Terminate DMA before pushing data on RX timeout
	perf cpumap: Fix snprintf overflow check
	cpufreq: powernv: Fix frame-size-overflow in powernv_cpufreq_work_fn
	tools: gpio-hammer: Avoid potential overflow in main
	nvme-multipath: do not reset on unknown status
	nvme: Fix controller creation races with teardown flow
	RDMA/rxe: Set sys_image_guid to be aligned with HW IB devices
	scsi: hpsa: correct race condition in offload enabled
	SUNRPC: Fix a potential buffer overflow in 'svc_print_xprts()'
	svcrdma: Fix leak of transport addresses
	PCI: Use ioremap(), not phys_to_virt() for platform ROM
	ubifs: Fix out-of-bounds memory access caused by abnormal value of node_len
	ALSA: usb-audio: Fix case when USB MIDI interface has more than one extra endpoint descriptor
	PCI: pciehp: Fix MSI interrupt race
	NFS: Fix races nfs_page_group_destroy() vs nfs_destroy_unlinked_subrequests()
	mm/kmemleak.c: use address-of operator on section symbols
	mm/filemap.c: clear page error before actual read
	mm/vmscan.c: fix data races using kswapd_classzone_idx
	nvmet-rdma: fix double free of rdma queue
	mm/mmap.c: initialize align_offset explicitly for vm_unmapped_area
	scsi: qedi: Fix termination timeouts in session logout
	serial: uartps: Wait for tx_empty in console setup
	KVM: Remove CREATE_IRQCHIP/SET_PIT2 race
	bdev: Reduce time holding bd_mutex in sync in blkdev_close()
	drivers: char: tlclk.c: Avoid data race between init and interrupt handler
	KVM: arm64: vgic-its: Fix memory leak on the error path of vgic_add_lpi()
	net: openvswitch: use u64 for meter bucket
	scsi: aacraid: Fix error handling paths in aac_probe_one()
	staging:r8188eu: avoid skb_clone for amsdu to msdu conversion
	sparc64: vcc: Fix error return code in vcc_probe()
	arm64: cpufeature: Relax checks for AArch32 support at EL[0-2]
	dt-bindings: sound: wm8994: Correct required supplies based on actual implementaion
	atm: fix a memory leak of vcc->user_back
	perf mem2node: Avoid double free related to realloc
	power: supply: max17040: Correct voltage reading
	phy: samsung: s5pv210-usb2: Add delay after reset
	Bluetooth: Handle Inquiry Cancel error after Inquiry Complete
	USB: EHCI: ehci-mv: fix error handling in mv_ehci_probe()
	tipc: fix memory leak in service subscripting
	tty: serial: samsung: Correct clock selection logic
	ALSA: hda: Fix potential race in unsol event handler
	powerpc/traps: Make unrecoverable NMIs die instead of panic
	fuse: don't check refcount after stealing page
	USB: EHCI: ehci-mv: fix less than zero comparison of an unsigned int
	scsi: cxlflash: Fix error return code in cxlflash_probe()
	arm64/cpufeature: Drop TraceFilt feature exposure from ID_DFR0 register
	e1000: Do not perform reset in reset_task if we are already down
	drm/nouveau/debugfs: fix runtime pm imbalance on error
	drm/nouveau: fix runtime pm imbalance on error
	drm/nouveau/dispnv50: fix runtime pm imbalance on error
	printk: handle blank console arguments passed in.
	usb: dwc3: Increase timeout for CmdAct cleared by device controller
	btrfs: don't force read-only after error in drop snapshot
	vfio/pci: fix memory leaks of eventfd ctx
	perf evsel: Fix 2 memory leaks
	perf trace: Fix the selection for architectures to generate the errno name tables
	perf stat: Fix duration_time value for higher intervals
	perf util: Fix memory leak of prefix_if_not_in
	perf metricgroup: Free metric_events on error
	perf kcore_copy: Fix module map when there are no modules loaded
	ASoC: img-i2s-out: Fix runtime PM imbalance on error
	wlcore: fix runtime pm imbalance in wl1271_tx_work
	wlcore: fix runtime pm imbalance in wlcore_regdomain_config
	mtd: rawnand: omap_elm: Fix runtime PM imbalance on error
	PCI: tegra: Fix runtime PM imbalance on error
	ceph: fix potential race in ceph_check_caps
	mm/swap_state: fix a data race in swapin_nr_pages
	rapidio: avoid data race between file operation callbacks and mport_cdev_add().
	mtd: parser: cmdline: Support MTD names containing one or more colons
	x86/speculation/mds: Mark mds_user_clear_cpu_buffers() __always_inline
	vfio/pci: Clear error and request eventfd ctx after releasing
	cifs: Fix double add page to memcg when cifs_readpages
	nvme: fix possible deadlock when I/O is blocked
	scsi: libfc: Handling of extra kref
	scsi: libfc: Skip additional kref updating work event
	selftests/x86/syscall_nt: Clear weird flags after each test
	vfio/pci: fix racy on error and request eventfd ctx
	btrfs: qgroup: fix data leak caused by race between writeback and truncate
	ubi: fastmap: Free unused fastmap anchor peb during detach
	perf parse-events: Use strcmp() to compare the PMU name
	net: openvswitch: use div_u64() for 64-by-32 divisions
	nvme: explicitly update mpath disk capacity on revalidation
	ASoC: wm8994: Skip setting of the WM8994_MICBIAS register for WM1811
	ASoC: wm8994: Ensure the device is resumed in wm89xx_mic_detect functions
	ASoC: Intel: bytcr_rt5640: Add quirk for MPMAN Converter9 2-in-1
	RISC-V: Take text_mutex in ftrace_init_nop()
	s390/init: add missing __init annotations
	lockdep: fix order in trace_hardirqs_off_caller()
	drm/amdkfd: fix a memory leak issue
	i2c: core: Call i2c_acpi_install_space_handler() before i2c_acpi_register_devices()
	objtool: Fix noreturn detection for ignored functions
	ieee802154: fix one possible memleak in ca8210_dev_com_init
	ieee802154/adf7242: check status of adf7242_read_reg
	clocksource/drivers/h8300_timer8: Fix wrong return value in h8300_8timer_init()
	mwifiex: Increase AES key storage size to 256 bits
	batman-adv: bla: fix type misuse for backbone_gw hash indexing
	atm: eni: fix the missed pci_disable_device() for eni_init_one()
	batman-adv: mcast/TT: fix wrongly dropped or rerouted packets
	mac802154: tx: fix use-after-free
	bpf: Fix clobbering of r2 in bpf_gen_ld_abs
	drm/vc4/vc4_hdmi: fill ASoC card owner
	net: qed: RDMA personality shouldn't fail VF load
	drm/sun4i: sun8i-csc: Secondary CSC register correction
	batman-adv: Add missing include for in_interrupt()
	batman-adv: mcast: fix duplicate mcast packets in BLA backbone from mesh
	batman-adv: mcast: fix duplicate mcast packets from BLA backbone to mesh
	bpf: Fix a rcu warning for bpffs map pretty-print
	ALSA: asihpi: fix iounmap in error handler
	regmap: fix page selection for noinc reads
	MIPS: Add the missing 'CPU_1074K' into __get_cpu_type()
	KVM: x86: Reset MMU context if guest toggles CR4.SMAP or CR4.PKE
	KVM: SVM: Add a dedicated INVD intercept routine
	tracing: fix double free
	s390/dasd: Fix zero write for FBA devices
	kprobes: Fix to check probe enabled before disarm_kprobe_ftrace()
	mm, THP, swap: fix allocating cluster for swapfile by mistake
	s390/zcrypt: Fix ZCRYPT_PERDEV_REQCNT ioctl
	kprobes: Fix compiler warning for !CONFIG_KPROBES_ON_FTRACE
	ata: define AC_ERR_OK
	ata: make qc_prep return ata_completion_errors
	ata: sata_mv, avoid trigerrable BUG_ON
	KVM: arm64: Assume write fault on S1PTW permission fault on instruction fetch
	Linux 4.19.149

Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
Change-Id: Idfc1b35ec63b4b464aeb6e32709102bee0efc872

Greg Kroah-Hartman   commited 2020-10-01 16:49:05 +02:00
9ce79d9bed
fix dget_parent() fastpath race
[ Upstream commit e84009336711d2bba885fc9cea66348ddfce3758 ]

We are overoptimistic about taking the fast path there; seeing
the same value in ->d_parent after having grabbed a reference
to that parent does *not* mean that it has remained our parent
all along.

That wouldn't be a big deal (in the end it is our parent and
we have grabbed the reference we are about to return), but...
the situation with barriers is messed up.

We might have hit the following sequence:

d is a dentry of /tmp/a/b
CPU1:					CPU2:
parent = d->d_parent (i.e. dentry of /tmp/a)
					rename /tmp/a/b to /tmp/b
					rmdir /tmp/a, making its dentry negative
grab reference to parent,
end up with cached parent->d_inode (NULL)
					mkdir /tmp/a, rename /tmp/b to /tmp/a/b
recheck d->d_parent, which is back to original
decide that everything's fine and return the reference we'd got.

The trouble is, caller (on CPU1) will observe dget_parent()
returning an apparently negative dentry.  It actually is positive,
but CPU1 has stale ->d_inode cached.

Use d->d_seq to see if it has been moved instead of rechecking ->d_parent.
NOTE: we are *NOT* going to retry on any kind of ->d_seq mismatch;
we just go into the slow path in such case.  We don't wait for ->d_seq
to become even either - again, if we are racing with renames, we
can bloody well go to slow path anyway.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Sasha Levin <sashal@kernel.org>

Al Viro   authored and   Greg Kroah-Hartman   commited 2020-10-01 13:14:27 +02:00
98e151baab
UPSTREAM: dcache: allocate external names from reclaimable kmalloc caches
We can use the newly introduced kmalloc-reclaimable-X caches, to allocate
external names in dcache, which will take care of the proper accounting
automatically, and also improve anti-fragmentation page grouping.

This effectively reverts commit f1782c9bc5 ("dcache: account external
names as indirectly reclaimable memory") and instead passes
__GFP_RECLAIMABLE to kmalloc().  The accounting thus moves from
NR_INDIRECTLY_RECLAIMABLE_BYTES to NR_SLAB_RECLAIMABLE, which is also
considered in MemAvailable calculation and overcommit decisions.

Link: http://lkml.kernel.org/r/20180731090649.16028-4-vbabka@suse.cz
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Mel Gorman <mgorman@techsingularity.net>
Acked-by: Roman Gushchin <guro@fb.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Laura Abbott <labbott@redhat.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Sumit Semwal <sumit.semwal@linaro.org>
Cc: Vijayanand Jitta <vjitta@codeaurora.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

(cherry picked from commit 2e03b4bc4ae84fcc0eee00e5ba5d228901d38809)

Bug: 138148041
Test: verify KReclaimable accounting after ION allocation+deallocation
Change-Id: I7db8f9d202aed82dafa28b82ed6615927a63558d
Signed-off-by: Suren Baghdasaryan <surenb@google.com>

Vlastimil Babka   authored and   Suren Baghdasaryan   commited 2019-12-13 14:04:22 -08:00
0ca673b38f
Merge remote-tracking branch 'origin/upstream-f2fs-stable-linux-4.19.y' into android-4.19
* origin/upstream-f2fs-stable-linux-4.19.y:
  f2fs: use EINVAL for superblock with invalid magic
  f2fs: fix to read source block before invalidating it
  f2fs: remove redundant check from f2fs_setflags_common()
  f2fs: use generic checking function for FS_IOC_FSSETXATTR
  f2fs: use generic checking and prep function for FS_IOC_SETFLAGS
  ubifs, fscrypt: cache decrypted symlink target in ->i_link
  vfs: use READ_ONCE() to access ->i_link
  fs, fscrypt: clear DCACHE_ENCRYPTED_NAME when unaliasing directory
  fscrypt: cache decrypted symlink target in ->i_link
  fscrypt: fix race where ->lookup() marks plaintext dentry as ciphertext
  fscrypt: only set dentry_operations on ciphertext dentries
  fscrypt: fix race allowing rename() and link() of ciphertext dentries
  fscrypt: clean up and improve dentry revalidation
  fscrypt: use READ_ONCE() to access ->i_crypt_info
  fscrypt: remove WARN_ON_ONCE() when decryption fails
  fscrypt: drop inode argument from fscrypt_get_ctx()
  f2fs: improve print log in f2fs_sanity_check_ckpt()
  f2fs: avoid out-of-range memory access
  f2fs: fix to avoid long latency during umount
  f2fs: allow all the users to pin a file
  f2fs: support swap file w/ DIO
  f2fs: allocate blocks for pinned file
  f2fs: fix is_idle() check for discard type
  f2fs: add a rw_sem to cover quota flag changes
  f2fs: set SBI_NEED_FSCK for xattr corruption case
  f2fs: use generic EFSBADCRC/EFSCORRUPTED
  f2fs: Use DIV_ROUND_UP() instead of open-coding
  f2fs: print kernel message if filesystem is inconsistent
  f2fs: introduce f2fs_<level> macros to wrap f2fs_printk()
  f2fs: avoid get_valid_blocks() for cleanup
  f2fs: ioctl for removing a range from F2FS
  f2fs: only set project inherit bit for directory
  f2fs: separate f2fs i_flags from fs_flags and ext4 i_flags
  f2fs: Add option to limit required GC for checkpoint=disable
  f2fs: Fix accounting for unusable blocks
  f2fs: Fix root reserved on remount
  f2fs: Lower threshold for disable_cp_again
  f2fs: fix sparse warning
  f2fs: fix f2fs_show_options to show nodiscard mount option
  f2fs: add error prints for debugging mount failure
  f2fs: fix to do sanity check on segment bitmap of LFS curseg
  f2fs: add missing sysfs entries in documentation
  f2fs: fix to avoid deadloop if data_flush is on
  f2fs: always assume that the device is idle under gc_urgent
  f2fs: add bio cache for IPU
  f2fs: allow ssr block allocation during checkpoint=disable period
  f2fs: fix to check layout on last valid checkpoint park

Change-Id: Ie910f127f574c2115e5b9a6725461ce002c267be
Signed-off-by: Jaegeuk Kim <jaegeuk@google.com>

Jaegeuk Kim   commited 2019-07-31 21:34:30 -07:00
e6f3ddbf65
fs, fscrypt: clear DCACHE_ENCRYPTED_NAME when unaliasing directory
Make __d_move() clear DCACHE_ENCRYPTED_NAME on the source dentry.  This
is needed for when d_splice_alias() moves a directory's encrypted alias
to its decrypted alias as a result of the encryption key being added.

Otherwise, the decrypted alias will incorrectly be invalidated on the
next lookup, causing problems such as unmounting a mount the user just
mount()ed there.

Note that we don't have to support arbitrary moves of this flag because
fscrypt doesn't allow dentries with DCACHE_ENCRYPTED_NAME to be the
source or target of a rename().

Fixes: 28b4c26396 ("ext4 crypto: revalidate dentry after adding or removing the key")
Reported-by: Sarthak Kukreti <sarthakkukreti@chromium.org>
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

Eric Biggers   authored and   Jaegeuk Kim   commited 2019-07-30 09:55:43 -07:00
dd038b348f
dcache: sort the freeing-without-RCU-delay mess for good.
commit 5467a68cbf6884c9a9d91e2a89140afb1839c835 upstream.

For lockless accesses to dentries we don't have pinned we rely
(among other things) upon having an RCU delay between dropping
the last reference and actually freeing the memory.

On the other hand, for things like pipes and sockets we neither
do that kind of lockless access, nor want to deal with the
overhead of an RCU delay every time a socket gets closed.

So delay was made optional - setting DCACHE_RCUACCESS in ->d_flags
made sure it would happen.  We tried to avoid setting it unless
we knew we need it.  Unfortunately, that had led to recurring
class of bugs, in which we missed the need to set it.

We only really need it for dentries that are created by
d_alloc_pseudo(), so let's not bother with trying to be smart -
just make having an RCU delay the default.  The ones that do
*not* get it set the replacement flag (DCACHE_NORCU) and we'd
better use that sparingly.  d_alloc_pseudo() is the only
such user right now.

FWIW, the race that finally prompted that switch had been
between __lock_parent() of immediate subdirectory of what's
currently the root of a disconnected tree (e.g. from
open-by-handle in progress) racing with d_splice_alias()
elsewhere picking another alias for the same inode, either
on outright corrupted fs image, or (in case of open-by-handle
on NFS) that subdirectory having been just moved on server.
It's not easy to hit, so the sky is not falling, but that's
not the first race on similar missed cases and the logics
for settinf DCACHE_RCUACCESS has gotten ridiculously
convoluted.

Cc: stable@vger.kernel.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Al Viro   authored and   Greg Kroah-Hartman   commited 2019-05-25 18:23:26 +02:00
c939121b54
fs/dcache: Fix incorrect nr_dentry_unused accounting in shrink_dcache_sb()
commit 1dbd449c9943e3145148cc893c2461b72ba6fef0 upstream.

The nr_dentry_unused per-cpu counter tracks dentries in both the LRU
lists and the shrink lists where the DCACHE_LRU_LIST bit is set.

The shrink_dcache_sb() function moves dentries from the LRU list to a
shrink list and subtracts the dentry count from nr_dentry_unused.  This
is incorrect as the nr_dentry_unused count will also be decremented in
shrink_dentry_list() via d_shrink_del().

To fix this double decrement, the decrement in the shrink_dcache_sb()
function is taken out.

Fixes: 4e717f5c10 ("list_lru: remove special case function list_lru_dispose_all."
Cc: stable@kernel.org
Signed-off-by: Waiman Long <longman@redhat.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Waiman Long   authored and   Greg Kroah-Hartman   commited 2019-02-06 17:30:11 +01:00
bb4e1ff5a8
fs/dcache.c: fix kmemcheck splat at take_dentry_name_snapshot()
Since only dentry->d_name.len + 1 bytes out of DNAME_INLINE_LEN bytes
are initialized at __d_alloc(), we can't copy the whole size
unconditionally.

 WARNING: kmemcheck: Caught 32-bit read from uninitialized memory (ffff8fa27465ac50)
 636f6e66696766732e746d70000000000010000000000000020000000188ffff
  i i i i i i i i i i i i i u u u u u u u u u u i i i i i u u u u
                                  ^
 RIP: 0010:take_dentry_name_snapshot+0x28/0x50
 RSP: 0018:ffffa83000f5bdf8 EFLAGS: 00010246
 RAX: 0000000000000020 RBX: ffff8fa274b20550 RCX: 0000000000000002
 RDX: ffffa83000f5be40 RSI: ffff8fa27465ac50 RDI: ffffa83000f5be60
 RBP: ffffa83000f5bdf8 R08: ffffa83000f5be48 R09: 0000000000000001
 R10: ffff8fa27465ac00 R11: ffff8fa27465acc0 R12: ffff8fa27465ac00
 R13: ffff8fa27465acc0 R14: 0000000000000000 R15: 0000000000000000
 FS:  00007f79737ac8c0(0000) GS:ffffffff8fc30000(0000) knlGS:0000000000000000
 CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
 CR2: ffff8fa274c0b000 CR3: 0000000134aa7002 CR4: 00000000000606f0
  take_dentry_name_snapshot+0x28/0x50
  vfs_rename+0x128/0x870
  SyS_rename+0x3b2/0x3d0
  entry_SYSCALL_64_fastpath+0x1a/0xa4
  0xffffffffffffffff

Link: http://lkml.kernel.org/r/201709131912.GBG39012.QMJLOVFSFFOOtH@I-love.SAKURA.ne.jp
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: Vegard Nossum <vegard.nossum@gmail.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>

Tetsuo Handa   authored and   Linus Torvalds   commited 2018-08-17 16:20:28 -07:00
6cd00a01f0
Merge branches 'work.misc' and 'work.dcache' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull misc vfs updates from Al Viro:
 "Misc cleanups from various folks all over the place

  I expected more fs/dcache.c cleanups this cycle, so that went into a
  separate branch. Said cleanups have missed the window, so in the
  hindsight it could've gone into work.misc instead. Decided not to
  cherry-pick, thus the 'work.dcache' branch"

* 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  fs: dcache: Use true and false for boolean values
  fold generic_readlink() into its only caller
  fs: shave 8 bytes off of struct inode
  fs: Add more kernel-doc to the produced documentation
  fs: Fix attr.c kernel-doc
  removed extra extern file_fdatawait_range

* 'work.dcache' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  kill dentry_update_name_case()

Linus Torvalds   commited 2018-08-13 21:28:25 -07:00
4591343e35
Merge branch 'work.mkdir' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull vfs icache updates from Al Viro:

 - NFS mkdir/open_by_handle race fix

 - analogous solution for FUSE, replacing the one currently in mainline

 - new primitive to be used when discarding halfway set up inodes on
   failed object creation; gives sane warranties re icache lookups not
   returning such doomed by still not freed inodes. A bunch of
   filesystems switched to that animal.

 - Miklos' fix for last cycle regression in iget5_locked(); -stable will
   need a slightly different variant, unfortunately.

 - misc bits and pieces around things icache-related (in adfs and jfs).

* 'work.mkdir' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  jfs: don't bother with make_bad_inode() in ialloc()
  adfs: don't put inodes into icache
  new helper: inode_fake_hash()
  vfs: don't evict uninitialized inode
  jfs: switch to discard_new_inode()
  ext2: make sure that partially set up inodes won't be returned by ext2_iget()
  udf: switch to discard_new_inode()
  ufs: switch to discard_new_inode()
  btrfs: switch to discard_new_inode()
  new primitive: discard_new_inode()
  kill d_instantiate_no_diralias()
  nfs_instantiate(): prevent multiple aliases for directory inode

Linus Torvalds   commited 2018-08-13 20:25:58 -07:00
0ea97a2d61
make sure that __dentry_kill() always invalidates d_seq, unhashed or not
RCU pathwalk relies upon the assumption that anything that changes
->d_inode of a dentry will invalidate its ->d_seq.  That's almost
true - the one exception is that the final dput() of already unhashed
dentry does *not* touch ->d_seq at all.  Unhashing does, though,
so for anything we'd found by RCU dcache lookup we are fine.
Unfortunately, we can *start* with an unhashed dentry or jump into
it.

We could try and be careful in the (few) places where that could
happen.  Or we could just make the final dput() invalidate the damn
thing, unhashed or not.  The latter is much simpler and easier to
backport, so let's do it that way.

Reported-by: "Dae R. Jeong" <threeearcat@gmail.com>
Cc: stable@vger.kernel.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Al Viro   commited 2018-08-09 18:07:15 -04:00
4c0d7cd5c8
root dentries need RCU-delayed freeing
Since mountpoint crossing can happen without leaving lazy mode,
root dentries do need the same protection against having their
memory freed without RCU delay as everything else in the tree.

It's partially hidden by RCU delay between detaching from the
mount tree and dropping the vfsmount reference, but the starting
point of pathwalk can be on an already detached mount, in which
case umount-caused RCU delay has already passed by the time the
lazy pathwalk grabs rcu_read_lock().  If the starting point
happens to be at the root of that vfsmount *and* that vfsmount
covers the entire filesystem, we get trouble.

Fixes: 48a066e72d ("RCU'd vsfmounts")
Cc: stable@vger.kernel.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Al Viro   commited 2018-08-06 09:13:32 -04:00
90bad5e05b
fs: dcache: Use true and false for boolean values
Return statements in functions returning bool should use true or false
instead of an integer value.

This issue was detected with the help of Coccinelle.

Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Gustavo A. R. Silva   authored and   Al Viro   commited 2018-08-05 15:52:44 -04:00
7964410fcf
new primitive: discard_new_inode()
We don't want open-by-handle picking half-set-up in-core
struct inode from e.g. mkdir() having failed halfway through.
In other words, we don't want such inodes returned by iget_locked()
on their way to extinction.  However, we can't just have them
unhashed - otherwise open-by-handle immediately *after* that would've
ended up creating a new in-core inode over the on-disk one that
is in process of being freed right under us.

	Solution: new flag (I_CREATING) set by insert_inode_locked() and
removed by unlock_new_inode() and a new primitive (discard_new_inode())
to be used by such halfway-through-setup failure exits instead of
unlock_new_inode() / iput() combinations.  That primitive unlocks new
inode, but leaves I_CREATING in place.

	iget_locked() treats finding an I_CREATING inode as failure
(-ESTALE, once we sort out the error propagation).
	insert_inode_locked() treats the same as instant -EBUSY.
	ilookup() treats those as icache miss.

[Fix by Dan Carpenter <dan.carpenter@oracle.com> folded in]

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Al Viro   commited 2018-08-03 15:55:30 -04:00
c2b6d621c4
kill d_instantiate_no_diralias()
The only user is fuse_create_new_entry(), and there it's used to
mitigate the same mkdir/open-by-handle race as in nfs_mkdir().
The same solution applies - unhash the mkdir argument, then
call d_splice_alias() and if that returns a reference to preexisting
alias, dput() and report success.  ->mkdir() argument left unhashed
negative with the preexisting alias moved in the right place is just
fine from the ->mkdir() callers point of view.

Cc: Miklos Szeredi <miklos@szeredi.hu>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Al Viro   commited 2018-08-01 23:18:53 -04:00
c971e6a006
kill dentry_update_name_case()
the last user is gone

Spotted-by: Richard Weinberger <richard@nod.at>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Al Viro   commited 2018-06-23 17:16:44 -04:00
63a67a926e
Merge branch 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull misc vfs updates from Al Viro:
 "Misc bits and pieces not fitting into anything more specific"

* 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  vfs: delete unnecessary assignment in vfs_listxattr
  Documentation: filesystems: update filesystem locking documentation
  vfs: namei: use path_equal() in follow_dotdot()
  fs.h: fix outdated comment about file flags
  __inode_security_revalidate() never gets NULL opt_dentry
  make xattr_getsecurity() static
  vfat: simplify checks in vfat_lookup()
  get rid of dead code in d_find_alias()
  it's SB_BORN, not MS_BORN...
  msdos_rmdir(): kill BS comment
  remove rpc_rmdir()
  fs: avoid fdput() after failed fdget() in vfs_dedupe_file_range()

Linus Torvalds   commited 2018-06-04 10:14:28 -07:00
f956d08a56
Merge branch 'work.dcache' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull dcache updates from Al Viro:
 "This is the first part of dealing with livelocks etc around
  shrink_dcache_parent()."

* 'work.dcache' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  restore cond_resched() in shrink_dcache_parent()
  dput(): turn into explicit while() loop
  dcache: move cond_resched() into the end of __dentry_kill()
  d_walk(): kill 'finish' callback
  d_invalidate(): unhash immediately

Linus Torvalds   commited 2018-06-04 08:57:36 -07:00
06c86e66d6
get rid of dead code in d_find_alias()
All "try disconnected alias if nothing else fits" logics in d_find_alias()
got accidentally disabled by Neil a while ago; for most of the callers it
was the right thing to do, so fixes belong in few callers that *do* want
disconnected aliases.  This just takes the now-dead code in d_find_alias()
out.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Al Viro   commited 2018-05-13 12:08:32 -04:00
61fec493c9
do d_instantiate/unlock_new_inode combinations safely
For anything NFS-exported we do _not_ want to unlock new inode
before it has grown an alias; original set of fixes got the
ordering right, but missed the nasty complication in case of
lockdep being enabled - unlock_new_inode() does
	lockdep_annotate_inode_mutex_key(inode)
which can only be done before anyone gets a chance to touch
->i_mutex.  Unfortunately, flipping the order and doing
unlock_new_inode() before d_instantiate() opens a window when
mkdir can race with open-by-fhandle on a guessed fhandle, leading
to multiple aliases for a directory inode and all the breakage
that follows from that.

	Correct solution: a new primitive (d_instantiate_new())
combining these two in the right order - lockdep annotate, then
d_instantiate(), then the rest of unlock_new_inode().  All
combinations of d_instantiate() with unlock_new_inode() should
be converted to that.

Cc: stable@kernel.org	# 2.6.29 and later
Tested-by: Mike Marshall <hubcap@omnibond.com>
Reviewed-by: Andreas Dilger <adilger@dilger.ca>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Al Viro   commited 2018-05-11 15:36:37 -04:00
1e2e547a93
restore cond_resched() in shrink_dcache_parent()
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Al Viro   commited 2018-04-19 23:58:48 -04:00
4fb4887140
dput(): turn into explicit while() loop
No need to mess with gotos when the code yielded by straight while()
isn't any worse...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Al Viro   commited 2018-04-15 23:36:58 -04:00
1088a6408c
dcache: move cond_resched() into the end of __dentry_kill()
cond_resched() in shrink_dentry_list() is too early

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Al Viro   commited 2018-04-15 23:36:58 -04:00
9c5f1d3019
d_walk(): kill 'finish' callback
no users left

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Al Viro   commited 2018-04-15 23:36:57 -04:00
3a8e3611e0
d_invalidate(): unhash immediately
Once that is done, we can just hunt mountpoints down one by one;
no new mountpoints can be added from now on, so we don't need
anything tricky in finish() callback, etc.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Al Viro   commited 2018-04-15 23:36:57 -04:00
ff17fa561a
fs/dcache.c: add cond_resched() in shrink_dentry_list()
As previously reported (https://patchwork.kernel.org/patch/8642031/)
it's possible to call shrink_dentry_list with a large number of dentries
(> 10000).  This, in turn, could trigger the softlockup detector and
possibly trigger a panic.  In addition to the unmount path being
vulnerable to this scenario, at SuSE we've observed similar situation
happening during process exit on processes that touch a lot of dentries.
Here is an excerpt from a crash dump.  The number after the colon are
the number of dentries on the list passed to shrink_dentry_list:

PID 99760: 10722
PID 107530: 215
PID 108809: 24134
PID 108877: 21331
PID 141708: 16487

So we want to kill between 15k-25k dentries without yielding.

And one possible call stack looks like:

4 [ffff8839ece41db0] _raw_spin_lock at ffffffff8152a5f8
5 [ffff8839ece41db0] evict at ffffffff811c3026
6 [ffff8839ece41dd0] __dentry_kill at ffffffff811bf258
7 [ffff8839ece41df0] shrink_dentry_list at ffffffff811bf593
8 [ffff8839ece41e18] shrink_dcache_parent at ffffffff811bf830
9 [ffff8839ece41e50] proc_flush_task at ffffffff8120dd61
10 [ffff8839ece41ec0] release_task at ffffffff81059ebd
11 [ffff8839ece41f08] do_exit at ffffffff8105b8ce
12 [ffff8839ece41f78] sys_exit at ffffffff8105bd53
13 [ffff8839ece41f80] system_call_fastpath at ffffffff81532909

While some of the callers of shrink_dentry_list do use cond_resched,
this is not sufficient to prevent softlockups.  So just move
cond_resched into shrink_dentry_list from its callers.

David said: I've found hundreds of occurrences of warnings that we emit
when need_resched stays set for a prolonged period of time with the
stack trace that is included in the change log.

Link: http://lkml.kernel.org/r/1521718946-31521-1-git-send-email-nborisov@suse.com
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: David Rientjes <rientjes@google.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Goldwyn Rodrigues <rgoldwyn@suse.de>
Cc: Jeff Mahoney <jeffm@suse.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Nikolay Borisov   authored and   Linus Torvalds   commited 2018-04-11 10:28:38 -07:00
32785c0539
dcache: account external names as indirectly reclaimable memory
I received a report about suspicious growth of unreclaimable slabs on
some machines.  I've found that it happens on machines with low memory
pressure, and these unreclaimable slabs are external names attached to
dentries.

External names are allocated using generic kmalloc() function, so they
are accounted as unreclaimable.  But they are held by dentries, which
are reclaimable, and they will be reclaimed under the memory pressure.

In particular, this breaks MemAvailable calculation, as it doesn't take
unreclaimable slabs into account.  This leads to a silly situation, when
a machine is almost idle, has no memory pressure and therefore has a big
dentry cache.  And the resulting MemAvailable is too low to start a new
workload.

To address the issue, the NR_INDIRECTLY_RECLAIMABLE_BYTES counter is
used to track the amount of memory, consumed by external names.  The
counter is increased in the dentry allocation path, if an external name
structure is allocated; and it's decreased in the dentry freeing path.

To reproduce the problem I've used the following Python script:

  import os

  for iter in range (0, 10000000):
      try:
          name = ("/some_long_name_%d" % iter) + "_" * 220
          os.stat(name)
      except Exception:
          pass

Without this patch:
  $ cat /proc/meminfo | grep MemAvailable
  MemAvailable:    7811688 kB
  $ python indirect.py
  $ cat /proc/meminfo | grep MemAvailable
  MemAvailable:    2753052 kB

With the patch:
  $ cat /proc/meminfo | grep MemAvailable
  MemAvailable:    7809516 kB
  $ python indirect.py
  $ cat /proc/meminfo | grep MemAvailable
  MemAvailable:    7749144 kB

[guro@fb.com: fix indirectly reclaimable memory accounting for CONFIG_SLOB]
  Link: http://lkml.kernel.org/r/20180312194140.19517-1-guro@fb.com
[guro@fb.com: fix indirectly reclaimable memory accounting]
  Link: http://lkml.kernel.org/r/20180313125701.7955-1-guro@fb.com
Link: http://lkml.kernel.org/r/20180305133743.12746-5-guro@fb.com
Signed-off-by: Roman Gushchin <guro@fb.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Roman Gushchin   authored and   Linus Torvalds   commited 2018-04-11 10:28:29 -07:00
f1782c9bc5
d_genocide: move export to definition
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Al Viro   commited 2018-03-29 15:08:21 -04:00
cbd4a5bcb2
fold dentry_lock_for_move() into its sole caller and clean it up
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Al Viro   commited 2018-03-29 15:07:49 -04:00
42177007aa
make non-exchanging __d_move() copy ->d_parent rather than swap them
Currently d_move(from, to) does the following:
	* name/parent of from <- old name/parent of to, from hashed there
	* to is unhashed
	* name of to is preserved
	* if from used to be detached, to gets detached
	* if from used to be attached, parent of to <- old parent of from.

That's both user-visibly bogus and complicates reasoning a lot.
Much saner semantics would be
	* name/parent of from <- name/parent of to, from hashed there.
	* to is unhashed
	* name/parent of to is unchanged.

The price, of course, is that old parent of from might lose a reference.
However,
	* all potentially cross-directory callers of d_move() have both
parents pinned directly; typically, dentries themselves are grabbed
only after we have grabbed and locked both parents.  IOW, the decrement
of old parent's refcount in case of d_move() won't reach zero.
	* __d_move() from d_splice_alias() is done to detached alias.
No refcount decrements in that case
	* __d_move() from __d_unalias() *can* get the refcount to zero.
So let's grab a reference to alias' old parent before calling __d_unalias()
and dput() it after we'd dropped rename_lock.

That does make d_splice_alias() potentially blocking.  However, it has
no callers in non-sleepable contexts (and the case where we'd grown
that dget/dput pair is _very_ rare, so performance is not an issue).

Another thing that needs adjustment is unlocking in the end of __d_move();
folded it in.  And cleaned the remnants of bogus ordering from the
"lock them in the beginning" counterpart - it's never been right and
now (well, for 7 years now) we have that thing always serialized on
rename_lock anyway.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Al Viro   commited 2018-03-29 15:07:49 -04:00
076515fc92
split d_path() and friends into a separate file
Those parts of fs/dcache.c are pretty much self-contained.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Al Viro   commited 2018-03-29 15:07:46 -04:00
7a5cf791a7
dcache.c: trim includes
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Al Viro   commited 2018-03-29 15:07:45 -04:00
43986d63b6
fs/dcache: Avoid a try_lock loop in shrink_dentry_list()
shrink_dentry_list() holds dentry->d_lock and needs to acquire
dentry->d_inode->i_lock. This cannot be done with a spin_lock()
operation because it's the reverse of the regular lock order.
To avoid ABBA deadlocks it is done with a trylock loop.

Trylock loops are problematic in two scenarios:

  1) PREEMPT_RT converts spinlocks to 'sleeping' spinlocks, which are
     preemptible. As a consequence the i_lock holder can be preempted
     by a higher priority task. If that task executes the trylock loop
     it will do so forever and live lock.

  2) In virtual machines trylock loops are problematic as well. The
     VCPU on which the i_lock holder runs can be scheduled out and a
     task on a different VCPU can loop for a whole time slice. In the
     worst case this can lead to starvation. Commits 47be61845c
     ("fs/dcache.c: avoid soft-lockup in dput()") and 046b961b45
     ("shrink_dentry_list(): take parent's d_lock earlier") are
     addressing exactly those symptoms.

Avoid the trylock loop by using dentry_kill(). When pruning ancestors,
the same code applies that is used to kill a dentry in dput(). This
also has the benefit that the locking order is now the same. First
the inode is locked, then the parent.

Signed-off-by: John Ogness <john.ogness@linutronix.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

John Ogness   authored and   Al Viro   commited 2018-03-29 15:07:44 -04:00
8f04da2adb
get rid of trylock loop around dentry_kill()
In case when trylock in there fails, deal with it directly in
dentry_kill().  Note that in cases when we drop and retake
->d_lock, we need to recheck whether to retain the dentry.
Another thing is that dropping/retaking ->d_lock might have
ended up with negative dentry turning into positive; that,
of course, can happen only once...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Al Viro   commited 2018-03-29 15:07:44 -04:00
f657a666fd
handle move to LRU in retain_dentry()
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Al Viro   commited 2018-03-29 15:07:43 -04:00
62d9956cef
dput(): consolidate the "do we need to retain it?" into an inlined helper
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Al Viro   commited 2018-03-29 15:07:43 -04:00
a338579f2f
split the slow part of lock_parent() off
Turn the "trylock failed" part into uninlined __lock_parent().

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Al Viro   commited 2018-03-29 15:07:42 -04:00
8b987a46a1
now lock_parent() can't run into killed dentry
all remaining callers hold either a reference or ->i_lock

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Al Viro   commited 2018-03-29 15:07:42 -04:00
65d8eb5a8f
get rid of trylock loop in locking dentries on shrink list
In case of trylock failure don't re-add to the list - drop the locks
and carefully get them in the right order.  For shrink_dentry_list(),
somebody having grabbed a reference to dentry means that we can
kick it off-list, so if we find dentry being modified under us we
don't need to play silly buggers with retries anyway - off the list
it is.

The locking logics taken out into a helper of its own; lock_parent()
is no longer used for dentries that can be killed under us.

[fix from Eric Biggers folded]

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Al Viro   commited 2018-03-29 15:07:02 -04:00
3b3f09f48b
d_delete(): get rid of trylock loop
just grab ->i_lock first; we have a positive dentry, nothing's going
to happen to inode

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Al Viro   commited 2018-03-12 11:59:14 -04:00
c19457f0ae
fs/dcache: Move dentry_kill() below lock_parent()
A subsequent patch will modify dentry_kill() to call lock_parent().
Move the dentry_kill() implementation "as is" below lock_parent()
first. This will help simplify the review of the subsequent patch
with dentry_kill() changes.

Signed-off-by: John Ogness <john.ogness@linutronix.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

John Ogness   authored and   Al Viro   commited 2018-03-12 11:59:13 -04:00
c1d0c1a2b5
fs/dcache: Remove stale comment from dentry_kill()
Commit 0d98439ea3 ("vfs: use lockred "dead" flag to mark unrecoverably
dead dentries") removed the `ref' parameter in dentry_kill() but its
documentation remained. Remove it.

Signed-off-by: John Ogness <john.ogness@linutronix.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

John Ogness   authored and   Al Viro   commited 2018-03-12 11:59:13 -04:00
06080d100d
take write_seqcount_invalidate() into __d_drop()
... and reorder it with making d_unhashed() true.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Al Viro   commited 2018-03-12 11:59:12 -04:00
0632a9ac7b
fs: dcache: Use READ_ONCE when accessing i_dir_seq
i_dir_seq is subject to concurrent modification by a cmpxchg or
store-release operation, so ensure that the relaxed access in
d_alloc_parallel uses READ_ONCE.

Reported-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Will Deacon   authored and   Al Viro   commited 2018-02-25 12:51:10 -05:00
8cc07c808c
fs: dcache: Avoid livelock between d_alloc_parallel and __d_add
If d_alloc_parallel runs concurrently with __d_add, it is possible for
d_alloc_parallel to continuously retry whilst i_dir_seq has been
incremented to an odd value by __d_add:

CPU0:
__d_add
	n = start_dir_add(dir);
		cmpxchg(&dir->i_dir_seq, n, n + 1) == n

CPU1:
d_alloc_parallel
retry:
	seq = smp_load_acquire(&parent->d_inode->i_dir_seq) & ~1;
	hlist_bl_lock(b);
		bit_spin_lock(0, (unsigned long *)b); // Always succeeds

CPU0:
	__d_lookup_done(dentry)
		hlist_bl_lock
			bit_spin_lock(0, (unsigned long *)b); // Never succeeds

CPU1:
	if (unlikely(parent->d_inode->i_dir_seq != seq)) {
		hlist_bl_unlock(b);
		goto retry;
	}

Since the simple bit_spin_lock used to implement hlist_bl_lock does not
provide any fairness guarantees, then CPU1 can starve CPU0 of the lock
and prevent it from reaching end_dir_add(dir), therefore CPU1 cannot
exit its retry loop because the sequence number always has the bottom
bit set.

This patch resolves the livelock by not taking hlist_bl_lock in
d_alloc_parallel if the sequence counter is odd, since any subsequent
masked comparison with i_dir_seq will fail anyway.

Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Reported-by: Naresh Madhusudana <naresh.madhusudana@arm.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Matthew Wilcox <mawilcox@microsoft.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Will Deacon   authored and   Al Viro   commited 2018-02-25 12:51:09 -05:00
015555fd4d
lock_parent() needs to recheck if dentry got __dentry_kill'ed under it
In case when dentry passed to lock_parent() is protected from freeing only
by the fact that it's on a shrink list and trylock of parent fails, we
could get hit by __dentry_kill() (and subsequent dentry_kill(parent))
between unlocking dentry and locking presumed parent.  We need to recheck
that dentry is alive once we lock both it and parent *and* postpone
rcu_read_unlock() until after that point.  Otherwise we could return
a pointer to struct dentry that already is rcu-scheduled for freeing, with
->d_lock held on it; caller's subsequent attempt to unlock it can end
up with memory corruption.

Cc: stable@vger.kernel.org # 3.12+, counting backports
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Al Viro   commited 2018-02-23 20:47:17 -05:00
3b82140963
Merge branch 'overlayfs-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs
Pull overlayfs updates from Miklos Szeredi:
 "This work from Amir adds NFS export capability to overlayfs. NFS
  exporting an overlay filesystem is a challange because we want to keep
  track of any copy-up of a file or directory between encoding the file
  handle and decoding it.

  This is achieved by indexing copied up objects by lower layer file
  handle. The index is already used for hard links, this patchset
  extends the use to NFS file handle decoding"

* 'overlayfs-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs: (51 commits)
  ovl: check ERR_PTR() return value from ovl_encode_fh()
  ovl: fix regression in fsnotify of overlay merge dir
  ovl: wire up NFS export operations
  ovl: lookup indexed ancestor of lower dir
  ovl: lookup connected ancestor of dir in inode cache
  ovl: hash non-indexed dir by upper inode for NFS export
  ovl: decode pure lower dir file handles
  ovl: decode indexed dir file handles
  ovl: decode lower file handles of unlinked but open files
  ovl: decode indexed non-dir file handles
  ovl: decode lower non-dir file handles
  ovl: encode lower file handles
  ovl: copy up before encoding non-connectable dir file handle
  ovl: encode non-indexed upper file handles
  ovl: decode connected upper dir file handles
  ovl: decode pure upper file handles
  ovl: encode pure upper file handles
  ovl: document NFS export
  vfs: factor out helpers d_instantiate_anon() and d_alloc_anon()
  ovl: store 'has_upper' and 'opaque' as bit flags
  ...

Linus Torvalds   commited 2018-02-05 13:05:20 -08:00
139351f1f9
Currently, hardened usercopy performs dynamic bounds checking on slab
cache objects. This is good, but still leaves a lot of kernel memory
 available to be copied to/from userspace in the face of bugs. To further
 restrict what memory is available for copying, this creates a way to
 whitelist specific areas of a given slab cache object for copying to/from
 userspace, allowing much finer granularity of access control. Slab caches
 that are never exposed to userspace can declare no whitelist for their
 objects, thereby keeping them unavailable to userspace via dynamic copy
 operations. (Note, an implicit form of whitelisting is the use of constant
 sizes in usercopy operations and get_user()/put_user(); these bypass all
 hardened usercopy checks since these sizes cannot change at runtime.)
 
 This new check is WARN-by-default, so any mistakes can be found over the
 next several releases without breaking anyone's system.
 
 The series has roughly the following sections:
 - remove %p and improve reporting with offset
 - prepare infrastructure and whitelist kmalloc
 - update VFS subsystem with whitelists
 - update SCSI subsystem with whitelists
 - update network subsystem with whitelists
 - update process memory with whitelists
 - update per-architecture thread_struct with whitelists
 - update KVM with whitelists and fix ioctl bug
 - mark all other allocations as not whitelisted
 - update lkdtm for more sensible test overage
 -----BEGIN PGP SIGNATURE-----
 Version: GnuPG v1
 Comment: Kees Cook <kees@outflux.net>
 
 iQIcBAABCgAGBQJabvleAAoJEIly9N/cbcAmO1kQAJnjVPutnLSbnUteZxtsv7W4
 43Cggvokfxr6l08Yh3hUowNxZVKjhF9uwMVgRRg9Nl5WdYCN+vCQbHz+ZdzGJXKq
 cGqdKWgexMKX+aBdNDrK7BphUeD46sH7JWR+a/lDV/BgPxBCm9i5ZZCgXbPP89AZ
 NpLBji7gz49wMsnm/x135xtNlZ3dG0oKETzi7MiR+NtKtUGvoIszSKy5JdPZ4m8q
 9fnXmHqmwM6uQFuzDJPt1o+D1fusTuYnjI7EgyrJRRhQ+BB3qEFZApXnKNDRS9Dm
 uB7jtcwefJCjlZVCf2+PWTOEifH2WFZXLPFlC8f44jK6iRW2Nc+wVRisJ3vSNBG1
 gaRUe/FSge68eyfQj5OFiwM/2099MNkKdZ0fSOjEBeubQpiFChjgWgcOXa5Bhlrr
 C4CIhFV2qg/tOuHDAF+Q5S96oZkaTy5qcEEwhBSW15ySDUaRWFSrtboNt6ZVOhug
 d8JJvDCQWoNu1IQozcbv6xW/Rk7miy8c0INZ4q33YUvIZpH862+vgDWfTJ73Zy9H
 jR/8eG6t3kFHKS1vWdKZzOX1bEcnd02CGElFnFYUEewKoV7ZeeLsYX7zodyUAKyi
 Yp5CImsDbWWTsptBg6h9nt2TseXTxYCt2bbmpJcqzsqSCUwOQNQ4/YpuzLeG0ihc
 JgOmUnQNJWCTwUUw5AS1
 =tzmJ
 -----END PGP SIGNATURE-----

Merge tag 'usercopy-v4.16-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux

Pull hardened usercopy whitelisting from Kees Cook:
 "Currently, hardened usercopy performs dynamic bounds checking on slab
  cache objects. This is good, but still leaves a lot of kernel memory
  available to be copied to/from userspace in the face of bugs.

  To further restrict what memory is available for copying, this creates
  a way to whitelist specific areas of a given slab cache object for
  copying to/from userspace, allowing much finer granularity of access
  control.

  Slab caches that are never exposed to userspace can declare no
  whitelist for their objects, thereby keeping them unavailable to
  userspace via dynamic copy operations. (Note, an implicit form of
  whitelisting is the use of constant sizes in usercopy operations and
  get_user()/put_user(); these bypass all hardened usercopy checks since
  these sizes cannot change at runtime.)

  This new check is WARN-by-default, so any mistakes can be found over
  the next several releases without breaking anyone's system.

  The series has roughly the following sections:
   - remove %p and improve reporting with offset
   - prepare infrastructure and whitelist kmalloc
   - update VFS subsystem with whitelists
   - update SCSI subsystem with whitelists
   - update network subsystem with whitelists
   - update process memory with whitelists
   - update per-architecture thread_struct with whitelists
   - update KVM with whitelists and fix ioctl bug
   - mark all other allocations as not whitelisted
   - update lkdtm for more sensible test overage"

* tag 'usercopy-v4.16-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux: (38 commits)
  lkdtm: Update usercopy tests for whitelisting
  usercopy: Restrict non-usercopy caches to size 0
  kvm: x86: fix KVM_XEN_HVM_CONFIG ioctl
  kvm: whitelist struct kvm_vcpu_arch
  arm: Implement thread_struct whitelist for hardened usercopy
  arm64: Implement thread_struct whitelist for hardened usercopy
  x86: Implement thread_struct whitelist for hardened usercopy
  fork: Provide usercopy whitelisting for task_struct
  fork: Define usercopy region in thread_stack slab caches
  fork: Define usercopy region in mm_struct slab caches
  net: Restrict unwhitelisted proto caches to size 0
  sctp: Copy struct sctp_sock.autoclose to userspace using put_user()
  sctp: Define usercopy region in SCTP proto slab cache
  caif: Define usercopy region in caif proto slab cache
  ip: Define usercopy region in IP proto slab cache
  net: Define usercopy region in struct proto slab cache
  scsi: Define usercopy region in scsi_sense_cache slab cache
  cifs: Define usercopy region in cifs_request slab cache
  vxfs: Define usercopy region in vxfs_inode slab cache
  ufs: Define usercopy region in ufs_inode_cache slab cache
  ...

Linus Torvalds   commited 2018-02-03 16:25:42 -08:00
617aebe6a9
Merge branch 'KASAN-read_word_at_a_time'
Merge KASAN word-at-a-time fixups from Andrey Ryabinin.

The word-at-a-time optimizations have caused headaches for KASAN, since
the whole point is that we access byte streams in bigger chunks, and
KASAN can be unhappy about the potential extra access at the end of the
string.

We used to have a horrible hack in dcache, and then people got
complaints from the strscpy() case.  This fixes it all up properly, by
adding an explicit helper for the "access byte stream one word at a
time" case.

* emailed patches from Andrey Ryabinin <aryabinin@virtuozzo.com>:
  fs: dcache: Revert "manually unpoison dname after allocation to shut up kasan's reports"
  fs/dcache: Use read_word_at_a_time() in dentry_string_cmp()
  lib/strscpy: Shut up KASAN false-positives in strscpy()
  compiler.h: Add read_word_at_a_time() function.
  compiler.h, kasan: Avoid duplicating __read_once_size_nocheck()

Linus Torvalds   commited 2018-02-01 12:20:53 -08:00
8e44e6600c