[for-6.1 0/2] virtiofsd: Add support for FUSE_SYNCFS request

[for-6.1 0/2] virtiofsd: Add support for FUSE_SYNCFS request

[Greg Kurz]

FUSE_SYNCFS allows the client to flush the host page cache.
This isn't available in upstream linux yet, but the following
tree can be used to test:

https://gitlab.com/gkurz/linux/-/tree/virtio-fs-sync

Greg Kurz (2):
  Update linux headers to 5.12-rc8 + FUSE_SYNCFS
  virtiofsd: Add support for FUSE_SYNCFS request

 include/standard-headers/drm/drm_fourcc.h     | 23 ++++-
 include/standard-headers/linux/ethtool.h      | 54 ++++++-----
 include/standard-headers/linux/fuse.h         | 14 ++-
 include/standard-headers/linux/input.h        |  2 +-
 .../standard-headers/rdma/vmw_pvrdma-abi.h    |  7 ++
 linux-headers/asm-generic/unistd.h            |  4 +-
 linux-headers/asm-mips/unistd_n32.h           |  1 +
 linux-headers/asm-mips/unistd_n64.h           |  1 +
 linux-headers/asm-mips/unistd_o32.h           |  1 +
 linux-headers/asm-powerpc/kvm.h               |  2 +
 linux-headers/asm-powerpc/unistd_32.h         |  1 +
 linux-headers/asm-powerpc/unistd_64.h         |  1 +
 linux-headers/asm-s390/unistd_32.h            |  1 +
 linux-headers/asm-s390/unistd_64.h            |  1 +
 linux-headers/asm-x86/kvm.h                   |  1 +
 linux-headers/asm-x86/unistd_32.h             |  1 +
 linux-headers/asm-x86/unistd_64.h             |  1 +
 linux-headers/asm-x86/unistd_x32.h            |  1 +
 linux-headers/linux/kvm.h                     | 89 +++++++++++++++++++
 linux-headers/linux/vfio.h                    | 27 ++++++
 tools/virtiofsd/fuse_lowlevel.c               | 19 ++++
 tools/virtiofsd/fuse_lowlevel.h               | 13 +++
 tools/virtiofsd/passthrough_ll.c              | 29 ++++++
 tools/virtiofsd/passthrough_seccomp.c         |  1 +
 24 files changed, 268 insertions(+), 27 deletions(-)

-- 
2.26.3

[for-6.1 1/2] Update linux headers to 5.12-rc8 + FUSE_SYNCFS

[Greg Kurz]

NOT YET IN UPSTREAM LINUX. DO NOT MERGE.

Signed-off-by: Greg Kurz <groug@kaod.org>
---
 include/standard-headers/drm/drm_fourcc.h     | 23 ++++-
 include/standard-headers/linux/ethtool.h      | 54 ++++++-----
 include/standard-headers/linux/fuse.h         | 14 ++-
 include/standard-headers/linux/input.h        |  2 +-
 .../standard-headers/rdma/vmw_pvrdma-abi.h    |  7 ++
 linux-headers/asm-generic/unistd.h            |  4 +-
 linux-headers/asm-mips/unistd_n32.h           |  1 +
 linux-headers/asm-mips/unistd_n64.h           |  1 +
 linux-headers/asm-mips/unistd_o32.h           |  1 +
 linux-headers/asm-powerpc/kvm.h               |  2 +
 linux-headers/asm-powerpc/unistd_32.h         |  1 +
 linux-headers/asm-powerpc/unistd_64.h         |  1 +
 linux-headers/asm-s390/unistd_32.h            |  1 +
 linux-headers/asm-s390/unistd_64.h            |  1 +
 linux-headers/asm-x86/kvm.h                   |  1 +
 linux-headers/asm-x86/unistd_32.h             |  1 +
 linux-headers/asm-x86/unistd_64.h             |  1 +
 linux-headers/asm-x86/unistd_x32.h            |  1 +
 linux-headers/linux/kvm.h                     | 89 +++++++++++++++++++
 linux-headers/linux/vfio.h                    | 27 ++++++
 20 files changed, 206 insertions(+), 27 deletions(-)

diff --git a/include/standard-headers/drm/drm_fourcc.h b/include/standard-headers/drm/drm_fourcc.h
index c47e19810c05..a61ae520c2db 100644
--- a/include/standard-headers/drm/drm_fourcc.h
+++ b/include/standard-headers/drm/drm_fourcc.h
@@ -526,6 +526,25 @@ extern "C" {
  */
 #define I915_FORMAT_MOD_Y_TILED_GEN12_MC_CCS fourcc_mod_code(INTEL, 7)
 
+/*
+ * Intel Color Control Surface with Clear Color (CCS) for Gen-12 render
+ * compression.
+ *
+ * The main surface is Y-tiled and is at plane index 0 whereas CCS is linear
+ * and at index 1. The clear color is stored at index 2, and the pitch should
+ * be ignored. The clear color structure is 256 bits. The first 128 bits
+ * represents Raw Clear Color Red, Green, Blue and Alpha color each represented
+ * by 32 bits. The raw clear color is consumed by the 3d engine and generates
+ * the converted clear color of size 64 bits. The first 32 bits store the Lower
+ * Converted Clear Color value and the next 32 bits store the Higher Converted
+ * Clear Color value when applicable. The Converted Clear Color values are
+ * consumed by the DE. The last 64 bits are used to store Color Discard Enable
+ * and Depth Clear Value Valid which are ignored by the DE. A CCS cache line
+ * corresponds to an area of 4x1 tiles in the main surface. The main surface
+ * pitch is required to be a multiple of 4 tile widths.
+ */
+#define I915_FORMAT_MOD_Y_TILED_GEN12_RC_CCS_CC fourcc_mod_code(INTEL, 8)
+
 /*
  * Tiled, NV12MT, grouped in 64 (pixels) x 32 (lines) -sized macroblocks
  *
@@ -1035,9 +1054,9 @@ drm_fourcc_canonicalize_nvidia_format_mod(uint64_t modifier)
  * Not all combinations are valid, and different SoCs may support different
  * combinations of layout and options.
  */
-#define __fourcc_mod_amlogic_layout_mask 0xf
+#define __fourcc_mod_amlogic_layout_mask 0xff
 #define __fourcc_mod_amlogic_options_shift 8
-#define __fourcc_mod_amlogic_options_mask 0xf
+#define __fourcc_mod_amlogic_options_mask 0xff
 
 #define DRM_FORMAT_MOD_AMLOGIC_FBC(__layout, __options) \
 	fourcc_mod_code(AMLOGIC, \
diff --git a/include/standard-headers/linux/ethtool.h b/include/standard-headers/linux/ethtool.h
index 8bfd01d230da..8e166b3c49dd 100644
--- a/include/standard-headers/linux/ethtool.h
+++ b/include/standard-headers/linux/ethtool.h
@@ -26,6 +26,14 @@
  * have the same layout for 32-bit and 64-bit userland.
  */
 
+/* Note on reserved space.
+ * Reserved fields must not be accessed directly by user space because
+ * they may be replaced by a different field in the future. They must
+ * be initialized to zero before making the request, e.g. via memset
+ * of the entire structure or implicitly by not being set in a structure
+ * initializer.
+ */
+
 /**
  * struct ethtool_cmd - DEPRECATED, link control and status
  * This structure is DEPRECATED, please use struct ethtool_link_settings.
@@ -67,6 +75,7 @@
  *	and other link features that the link partner advertised
  *	through autonegotiation; 0 if unknown or not applicable.
  *	Read-only.
+ * @reserved: Reserved for future use; see the note on reserved space.
  *
  * The link speed in Mbps is split between @speed and @speed_hi.  Use
  * the ethtool_cmd_speed() and ethtool_cmd_speed_set() functions to
@@ -155,6 +164,7 @@ static inline uint32_t ethtool_cmd_speed(const struct ethtool_cmd *ep)
  * @bus_info: Device bus address.  This should match the dev_name()
  *	string for the underlying bus device, if there is one.  May be
  *	an empty string.
+ * @reserved2: Reserved for future use; see the note on reserved space.
  * @n_priv_flags: Number of flags valid for %ETHTOOL_GPFLAGS and
  *	%ETHTOOL_SPFLAGS commands; also the number of strings in the
  *	%ETH_SS_PRIV_FLAGS set
@@ -356,6 +366,7 @@ struct ethtool_eeprom {
  * @tx_lpi_timer: Time in microseconds the interface delays prior to asserting
  *	its tx lpi (after reaching 'idle' state). Effective only when eee
  *	was negotiated and tx_lpi_enabled was set.
+ * @reserved: Reserved for future use; see the note on reserved space.
  */
 struct ethtool_eee {
 	uint32_t	cmd;
@@ -374,6 +385,7 @@ struct ethtool_eee {
  * @cmd: %ETHTOOL_GMODULEINFO
  * @type: Standard the module information conforms to %ETH_MODULE_SFF_xxxx
  * @eeprom_len: Length of the eeprom
+ * @reserved: Reserved for future use; see the note on reserved space.
  *
  * This structure is used to return the information to
  * properly size memory for a subsequent call to %ETHTOOL_GMODULEEEPROM.
@@ -579,9 +591,7 @@ struct ethtool_pauseparam {
 	uint32_t	tx_pause;
 };
 
-/**
- * enum ethtool_link_ext_state - link extended state
- */
+/* Link extended state */
 enum ethtool_link_ext_state {
 	ETHTOOL_LINK_EXT_STATE_AUTONEG,
 	ETHTOOL_LINK_EXT_STATE_LINK_TRAINING_FAILURE,
@@ -595,10 +605,7 @@ enum ethtool_link_ext_state {
 	ETHTOOL_LINK_EXT_STATE_OVERHEAT,
 };
 
-/**
- * enum ethtool_link_ext_substate_autoneg - more information in addition to
- * ETHTOOL_LINK_EXT_STATE_AUTONEG.
- */
+/* More information in addition to ETHTOOL_LINK_EXT_STATE_AUTONEG. */
 enum ethtool_link_ext_substate_autoneg {
 	ETHTOOL_LINK_EXT_SUBSTATE_AN_NO_PARTNER_DETECTED = 1,
 	ETHTOOL_LINK_EXT_SUBSTATE_AN_ACK_NOT_RECEIVED,
@@ -608,9 +615,7 @@ enum ethtool_link_ext_substate_autoneg {
 	ETHTOOL_LINK_EXT_SUBSTATE_AN_NO_HCD,
 };
 
-/**
- * enum ethtool_link_ext_substate_link_training - more information in addition to
- * ETHTOOL_LINK_EXT_STATE_LINK_TRAINING_FAILURE.
+/* More information in addition to ETHTOOL_LINK_EXT_STATE_LINK_TRAINING_FAILURE.
  */
 enum ethtool_link_ext_substate_link_training {
 	ETHTOOL_LINK_EXT_SUBSTATE_LT_KR_FRAME_LOCK_NOT_ACQUIRED = 1,
@@ -619,9 +624,7 @@ enum ethtool_link_ext_substate_link_training {
 	ETHTOOL_LINK_EXT_SUBSTATE_LT_REMOTE_FAULT,
 };
 
-/**
- * enum ethtool_link_ext_substate_logical_mismatch - more information in addition
- * to ETHTOOL_LINK_EXT_STATE_LINK_LOGICAL_MISMATCH.
+/* More information in addition to ETHTOOL_LINK_EXT_STATE_LINK_LOGICAL_MISMATCH.
  */
 enum ethtool_link_ext_substate_link_logical_mismatch {
 	ETHTOOL_LINK_EXT_SUBSTATE_LLM_PCS_DID_NOT_ACQUIRE_BLOCK_LOCK = 1,
@@ -631,19 +634,14 @@ enum ethtool_link_ext_substate_link_logical_mismatch {
 	ETHTOOL_LINK_EXT_SUBSTATE_LLM_RS_FEC_IS_NOT_LOCKED,
 };
 
-/**
- * enum ethtool_link_ext_substate_bad_signal_integrity - more information in
- * addition to ETHTOOL_LINK_EXT_STATE_BAD_SIGNAL_INTEGRITY.
+/* More information in addition to ETHTOOL_LINK_EXT_STATE_BAD_SIGNAL_INTEGRITY.
  */
 enum ethtool_link_ext_substate_bad_signal_integrity {
 	ETHTOOL_LINK_EXT_SUBSTATE_BSI_LARGE_NUMBER_OF_PHYSICAL_ERRORS = 1,
 	ETHTOOL_LINK_EXT_SUBSTATE_BSI_UNSUPPORTED_RATE,
 };
 
-/**
- * enum ethtool_link_ext_substate_cable_issue - more information in
- * addition to ETHTOOL_LINK_EXT_STATE_CABLE_ISSUE.
- */
+/* More information in addition to ETHTOOL_LINK_EXT_STATE_CABLE_ISSUE. */
 enum ethtool_link_ext_substate_cable_issue {
 	ETHTOOL_LINK_EXT_SUBSTATE_CI_UNSUPPORTED_CABLE = 1,
 	ETHTOOL_LINK_EXT_SUBSTATE_CI_CABLE_TEST_FAILURE,
@@ -661,6 +659,7 @@ enum ethtool_link_ext_substate_cable_issue {
  *	now deprecated
  * @ETH_SS_FEATURES: Device feature names
  * @ETH_SS_RSS_HASH_FUNCS: RSS hush function names
+ * @ETH_SS_TUNABLES: tunable names
  * @ETH_SS_PHY_STATS: Statistic names, for use with %ETHTOOL_GPHYSTATS
  * @ETH_SS_PHY_TUNABLES: PHY tunable names
  * @ETH_SS_LINK_MODES: link mode names
@@ -670,6 +669,8 @@ enum ethtool_link_ext_substate_cable_issue {
  * @ETH_SS_TS_TX_TYPES: timestamping Tx types
  * @ETH_SS_TS_RX_FILTERS: timestamping Rx filters
  * @ETH_SS_UDP_TUNNEL_TYPES: UDP tunnel types
+ *
+ * @ETH_SS_COUNT: number of defined string sets
  */
 enum ethtool_stringset {
 	ETH_SS_TEST		= 0,
@@ -715,6 +716,7 @@ struct ethtool_gstrings {
 /**
  * struct ethtool_sset_info - string set information
  * @cmd: Command number = %ETHTOOL_GSSET_INFO
+ * @reserved: Reserved for future use; see the note on reserved space.
  * @sset_mask: On entry, a bitmask of string sets to query, with bits
  *	numbered according to &enum ethtool_stringset.  On return, a
  *	bitmask of those string sets queried that are supported.
@@ -759,6 +761,7 @@ enum ethtool_test_flags {
  * @flags: A bitmask of flags from &enum ethtool_test_flags.  Some
  *	flags may be set by the user on entry; others may be set by
  *	the driver on return.
+ * @reserved: Reserved for future use; see the note on reserved space.
  * @len: On return, the number of test results
  * @data: Array of test results
  *
@@ -959,6 +962,7 @@ union ethtool_flow_union {
  * @vlan_etype: VLAN EtherType
  * @vlan_tci: VLAN tag control information
  * @data: user defined data
+ * @padding: Reserved for future use; see the note on reserved space.
  *
  * Note, @vlan_etype, @vlan_tci, and @data are only valid if %FLOW_EXT
  * is set in &struct ethtool_rx_flow_spec @flow_type.
@@ -1134,7 +1138,8 @@ struct ethtool_rxfh_indir {
  *	hardware hash key.
  * @hfunc: Defines the current RSS hash function used by HW (or to be set to).
  *	Valid values are one of the %ETH_RSS_HASH_*.
- * @rsvd:	Reserved for future extensions.
+ * @rsvd8: Reserved for future use; see the note on reserved space.
+ * @rsvd32: Reserved for future use; see the note on reserved space.
  * @rss_config: RX ring/queue index for each hash value i.e., indirection table
  *	of @indir_size uint32_t elements, followed by hash key of @key_size
  *	bytes.
@@ -1302,7 +1307,9 @@ struct ethtool_sfeatures {
  * @so_timestamping: bit mask of the sum of the supported SO_TIMESTAMPING flags
  * @phc_index: device index of the associated PHC, or -1 if there is none
  * @tx_types: bit mask of the supported hwtstamp_tx_types enumeration values
+ * @tx_reserved: Reserved for future use; see the note on reserved space.
  * @rx_filters: bit mask of the supported hwtstamp_rx_filters enumeration values
+ * @rx_reserved: Reserved for future use; see the note on reserved space.
  *
  * The bits in the 'tx_types' and 'rx_filters' fields correspond to
  * the 'hwtstamp_tx_types' and 'hwtstamp_rx_filters' enumeration values,
@@ -1958,6 +1965,11 @@ enum ethtool_reset_flags {
  *	autonegotiation; 0 if unknown or not applicable.  Read-only.
  * @transceiver: Used to distinguish different possible PHY types,
  *	reported consistently by PHYLIB.  Read-only.
+ * @master_slave_cfg: Master/slave port mode.
+ * @master_slave_state: Master/slave port state.
+ * @reserved: Reserved for future use; see the note on reserved space.
+ * @reserved1: Reserved for future use; see the note on reserved space.
+ * @link_mode_masks: Variable length bitmaps.
  *
  * If autonegotiation is disabled, the speed and @duplex represent the
  * fixed link mode and are writable if the driver supports multiple
diff --git a/include/standard-headers/linux/fuse.h b/include/standard-headers/linux/fuse.h
index 950d7edb7ef6..8950991b69cc 100644
--- a/include/standard-headers/linux/fuse.h
+++ b/include/standard-headers/linux/fuse.h
@@ -179,6 +179,9 @@
  *  7.33
  *  - add FUSE_HANDLE_KILLPRIV_V2, FUSE_WRITE_KILL_SUIDGID, FATTR_KILL_SUIDGID
  *  - add FUSE_OPEN_KILL_SUIDGID
+ *
+ *  7.34
+ *  - add FUSE_SYNCFS
  */
 
 #ifndef _LINUX_FUSE_H
@@ -210,7 +213,7 @@
 #define FUSE_KERNEL_VERSION 7
 
 /** Minor version number of this interface */
-#define FUSE_KERNEL_MINOR_VERSION 33
+#define FUSE_KERNEL_MINOR_VERSION 34
 
 /** The node ID of the root inode */
 #define FUSE_ROOT_ID 1
@@ -495,6 +498,7 @@ enum fuse_opcode {
 	FUSE_COPY_FILE_RANGE	= 47,
 	FUSE_SETUPMAPPING	= 48,
 	FUSE_REMOVEMAPPING	= 49,
+	FUSE_SYNCFS		= 50,
 
 	/* CUSE specific operations */
 	CUSE_INIT		= 4096,
@@ -899,7 +903,8 @@ struct fuse_notify_retrieve_in {
 };
 
 /* Device ioctls: */
-#define FUSE_DEV_IOC_CLONE	_IOR(229, 0, uint32_t)
+#define FUSE_DEV_IOC_MAGIC		229
+#define FUSE_DEV_IOC_CLONE		_IOR(FUSE_DEV_IOC_MAGIC, 0, uint32_t)
 
 struct fuse_lseek_in {
 	uint64_t	fh;
@@ -952,4 +957,9 @@ struct fuse_removemapping_one {
 #define FUSE_REMOVEMAPPING_MAX_ENTRY   \
 		(PAGE_SIZE / sizeof(struct fuse_removemapping_one))
 
+struct fuse_syncfs_in {
+	/* Whether to wait for outstanding I/Os to complete */
+	uint32_t wait;
+};
+
 #endif /* _LINUX_FUSE_H */
diff --git a/include/standard-headers/linux/input.h b/include/standard-headers/linux/input.h
index f89c986190de..7822c2417849 100644
--- a/include/standard-headers/linux/input.h
+++ b/include/standard-headers/linux/input.h
@@ -81,7 +81,7 @@ struct input_id {
  * in units per radian.
  * When INPUT_PROP_ACCELEROMETER is set the resolution changes.
  * The main axes (ABS_X, ABS_Y, ABS_Z) are then reported in
- * in units per g (units/g) and in units per degree per second
+ * units per g (units/g) and in units per degree per second
  * (units/deg/s) for rotational axes (ABS_RX, ABS_RY, ABS_RZ).
  */
 struct input_absinfo {
diff --git a/include/standard-headers/rdma/vmw_pvrdma-abi.h b/include/standard-headers/rdma/vmw_pvrdma-abi.h
index 0989426a3f52..c30182a7ae7e 100644
--- a/include/standard-headers/rdma/vmw_pvrdma-abi.h
+++ b/include/standard-headers/rdma/vmw_pvrdma-abi.h
@@ -133,6 +133,13 @@ enum pvrdma_wc_flags {
 	PVRDMA_WC_FLAGS_MAX		= PVRDMA_WC_WITH_NETWORK_HDR_TYPE,
 };
 
+enum pvrdma_network_type {
+	PVRDMA_NETWORK_IB,
+	PVRDMA_NETWORK_ROCE_V1 = PVRDMA_NETWORK_IB,
+	PVRDMA_NETWORK_IPV4,
+	PVRDMA_NETWORK_IPV6
+};
+
 struct pvrdma_alloc_ucontext_resp {
 	uint32_t qp_tab_size;
 	uint32_t reserved;
diff --git a/linux-headers/asm-generic/unistd.h b/linux-headers/asm-generic/unistd.h
index 728752917785..ce58cff99b66 100644
--- a/linux-headers/asm-generic/unistd.h
+++ b/linux-headers/asm-generic/unistd.h
@@ -861,9 +861,11 @@ __SYSCALL(__NR_faccessat2, sys_faccessat2)
 __SYSCALL(__NR_process_madvise, sys_process_madvise)
 #define __NR_epoll_pwait2 441
 __SC_COMP(__NR_epoll_pwait2, sys_epoll_pwait2, compat_sys_epoll_pwait2)
+#define __NR_mount_setattr 442
+__SYSCALL(__NR_mount_setattr, sys_mount_setattr)
 
 #undef __NR_syscalls
-#define __NR_syscalls 442
+#define __NR_syscalls 443
 
 /*
  * 32 bit systems traditionally used different
diff --git a/linux-headers/asm-mips/unistd_n32.h b/linux-headers/asm-mips/unistd_n32.h
index 59e53b6e076f..2ca45a01225b 100644
--- a/linux-headers/asm-mips/unistd_n32.h
+++ b/linux-headers/asm-mips/unistd_n32.h
@@ -371,6 +371,7 @@
 #define __NR_faccessat2	(__NR_Linux + 439)
 #define __NR_process_madvise	(__NR_Linux + 440)
 #define __NR_epoll_pwait2	(__NR_Linux + 441)
+#define __NR_mount_setattr	(__NR_Linux + 442)
 
 
 #endif /* _ASM_MIPS_UNISTD_N32_H */
diff --git a/linux-headers/asm-mips/unistd_n64.h b/linux-headers/asm-mips/unistd_n64.h
index 683558a7f8ad..c8df45e69cbb 100644
--- a/linux-headers/asm-mips/unistd_n64.h
+++ b/linux-headers/asm-mips/unistd_n64.h
@@ -347,6 +347,7 @@
 #define __NR_faccessat2	(__NR_Linux + 439)
 #define __NR_process_madvise	(__NR_Linux + 440)
 #define __NR_epoll_pwait2	(__NR_Linux + 441)
+#define __NR_mount_setattr	(__NR_Linux + 442)
 
 
 #endif /* _ASM_MIPS_UNISTD_N64_H */
diff --git a/linux-headers/asm-mips/unistd_o32.h b/linux-headers/asm-mips/unistd_o32.h
index ca6a7e5c0b91..10ba4cf9f579 100644
--- a/linux-headers/asm-mips/unistd_o32.h
+++ b/linux-headers/asm-mips/unistd_o32.h
@@ -417,6 +417,7 @@
 #define __NR_faccessat2	(__NR_Linux + 439)
 #define __NR_process_madvise	(__NR_Linux + 440)
 #define __NR_epoll_pwait2	(__NR_Linux + 441)
+#define __NR_mount_setattr	(__NR_Linux + 442)
 
 
 #endif /* _ASM_MIPS_UNISTD_O32_H */
diff --git a/linux-headers/asm-powerpc/kvm.h b/linux-headers/asm-powerpc/kvm.h
index c3af3f324c5a..9f18fa090f1f 100644
--- a/linux-headers/asm-powerpc/kvm.h
+++ b/linux-headers/asm-powerpc/kvm.h
@@ -644,6 +644,8 @@ struct kvm_ppc_cpu_char {
 #define KVM_REG_PPC_MMCR3	(KVM_REG_PPC | KVM_REG_SIZE_U64 | 0xc1)
 #define KVM_REG_PPC_SIER2	(KVM_REG_PPC | KVM_REG_SIZE_U64 | 0xc2)
 #define KVM_REG_PPC_SIER3	(KVM_REG_PPC | KVM_REG_SIZE_U64 | 0xc3)
+#define KVM_REG_PPC_DAWR1	(KVM_REG_PPC | KVM_REG_SIZE_U64 | 0xc4)
+#define KVM_REG_PPC_DAWRX1	(KVM_REG_PPC | KVM_REG_SIZE_U64 | 0xc5)
 
 /* Transactional Memory checkpointed state:
  * This is all GPRs, all VSX regs and a subset of SPRs
diff --git a/linux-headers/asm-powerpc/unistd_32.h b/linux-headers/asm-powerpc/unistd_32.h
index 4624c9004368..1d63e42fc4ec 100644
--- a/linux-headers/asm-powerpc/unistd_32.h
+++ b/linux-headers/asm-powerpc/unistd_32.h
@@ -424,6 +424,7 @@
 #define __NR_faccessat2	439
 #define __NR_process_madvise	440
 #define __NR_epoll_pwait2	441
+#define __NR_mount_setattr	442
 
 
 #endif /* _ASM_POWERPC_UNISTD_32_H */
diff --git a/linux-headers/asm-powerpc/unistd_64.h b/linux-headers/asm-powerpc/unistd_64.h
index 7e851b30bb13..6a8708c0c53d 100644
--- a/linux-headers/asm-powerpc/unistd_64.h
+++ b/linux-headers/asm-powerpc/unistd_64.h
@@ -396,6 +396,7 @@
 #define __NR_faccessat2	439
 #define __NR_process_madvise	440
 #define __NR_epoll_pwait2	441
+#define __NR_mount_setattr	442
 
 
 #endif /* _ASM_POWERPC_UNISTD_64_H */
diff --git a/linux-headers/asm-s390/unistd_32.h b/linux-headers/asm-s390/unistd_32.h
index c94d2c3a22d6..e5efe406e3d9 100644
--- a/linux-headers/asm-s390/unistd_32.h
+++ b/linux-headers/asm-s390/unistd_32.h
@@ -414,5 +414,6 @@
 #define __NR_faccessat2 439
 #define __NR_process_madvise 440
 #define __NR_epoll_pwait2 441
+#define __NR_mount_setattr 442
 
 #endif /* _ASM_S390_UNISTD_32_H */
diff --git a/linux-headers/asm-s390/unistd_64.h b/linux-headers/asm-s390/unistd_64.h
index 984a06b7ebe4..f0392fc6c771 100644
--- a/linux-headers/asm-s390/unistd_64.h
+++ b/linux-headers/asm-s390/unistd_64.h
@@ -362,5 +362,6 @@
 #define __NR_faccessat2 439
 #define __NR_process_madvise 440
 #define __NR_epoll_pwait2 441
+#define __NR_mount_setattr 442
 
 #endif /* _ASM_S390_UNISTD_64_H */
diff --git a/linux-headers/asm-x86/kvm.h b/linux-headers/asm-x86/kvm.h
index 8e76d3701db3..5a3022c8af82 100644
--- a/linux-headers/asm-x86/kvm.h
+++ b/linux-headers/asm-x86/kvm.h
@@ -112,6 +112,7 @@ struct kvm_ioapic_state {
 #define KVM_NR_IRQCHIPS          3
 
 #define KVM_RUN_X86_SMM		 (1 << 0)
+#define KVM_RUN_X86_BUS_LOCK     (1 << 1)
 
 /* for KVM_GET_REGS and KVM_SET_REGS */
 struct kvm_regs {
diff --git a/linux-headers/asm-x86/unistd_32.h b/linux-headers/asm-x86/unistd_32.h
index 18fb99dfa287..1374427c66fe 100644
--- a/linux-headers/asm-x86/unistd_32.h
+++ b/linux-headers/asm-x86/unistd_32.h
@@ -432,6 +432,7 @@
 #define __NR_faccessat2 439
 #define __NR_process_madvise 440
 #define __NR_epoll_pwait2 441
+#define __NR_mount_setattr 442
 
 
 #endif /* _ASM_X86_UNISTD_32_H */
diff --git a/linux-headers/asm-x86/unistd_64.h b/linux-headers/asm-x86/unistd_64.h
index bde959328d65..e9d0707bc37f 100644
--- a/linux-headers/asm-x86/unistd_64.h
+++ b/linux-headers/asm-x86/unistd_64.h
@@ -354,6 +354,7 @@
 #define __NR_faccessat2 439
 #define __NR_process_madvise 440
 #define __NR_epoll_pwait2 441
+#define __NR_mount_setattr 442
 
 
 #endif /* _ASM_X86_UNISTD_64_H */
diff --git a/linux-headers/asm-x86/unistd_x32.h b/linux-headers/asm-x86/unistd_x32.h
index 4ff6b17d3bb4..107aee76f2b1 100644
--- a/linux-headers/asm-x86/unistd_x32.h
+++ b/linux-headers/asm-x86/unistd_x32.h
@@ -307,6 +307,7 @@
 #define __NR_faccessat2 (__X32_SYSCALL_BIT + 439)
 #define __NR_process_madvise (__X32_SYSCALL_BIT + 440)
 #define __NR_epoll_pwait2 (__X32_SYSCALL_BIT + 441)
+#define __NR_mount_setattr (__X32_SYSCALL_BIT + 442)
 #define __NR_rt_sigaction (__X32_SYSCALL_BIT + 512)
 #define __NR_rt_sigreturn (__X32_SYSCALL_BIT + 513)
 #define __NR_ioctl (__X32_SYSCALL_BIT + 514)
diff --git a/linux-headers/linux/kvm.h b/linux-headers/linux/kvm.h
index 020b62a619a7..238c6c584725 100644
--- a/linux-headers/linux/kvm.h
+++ b/linux-headers/linux/kvm.h
@@ -216,6 +216,20 @@ struct kvm_hyperv_exit {
 	} u;
 };
 
+struct kvm_xen_exit {
+#define KVM_EXIT_XEN_HCALL          1
+	__u32 type;
+	union {
+		struct {
+			__u32 longmode;
+			__u32 cpl;
+			__u64 input;
+			__u64 result;
+			__u64 params[6];
+		} hcall;
+	} u;
+};
+
 #define KVM_S390_GET_SKEYS_NONE   1
 #define KVM_S390_SKEYS_MAX        1048576
 
@@ -251,6 +265,9 @@ struct kvm_hyperv_exit {
 #define KVM_EXIT_X86_RDMSR        29
 #define KVM_EXIT_X86_WRMSR        30
 #define KVM_EXIT_DIRTY_RING_FULL  31
+#define KVM_EXIT_AP_RESET_HOLD    32
+#define KVM_EXIT_X86_BUS_LOCK     33
+#define KVM_EXIT_XEN              34
 
 /* For KVM_EXIT_INTERNAL_ERROR */
 /* Emulate instruction failed. */
@@ -427,6 +444,8 @@ struct kvm_run {
 			__u32 index; /* kernel -> user */
 			__u64 data; /* kernel <-> user */
 		} msr;
+		/* KVM_EXIT_XEN */
+		struct kvm_xen_exit xen;
 		/* Fix the size of the union. */
 		char padding[256];
 	};
@@ -573,6 +592,7 @@ struct kvm_vapic_addr {
 #define KVM_MP_STATE_CHECK_STOP        6
 #define KVM_MP_STATE_OPERATING         7
 #define KVM_MP_STATE_LOAD              8
+#define KVM_MP_STATE_AP_RESET_HOLD     9
 
 struct kvm_mp_state {
 	__u32 mp_state;
@@ -1056,6 +1076,8 @@ struct kvm_ppc_resize_hpt {
 #define KVM_CAP_ENFORCE_PV_FEATURE_CPUID 190
 #define KVM_CAP_SYS_HYPERV_CPUID 191
 #define KVM_CAP_DIRTY_LOG_RING 192
+#define KVM_CAP_X86_BUS_LOCK_EXIT 193
+#define KVM_CAP_PPC_DAWR1 194
 
 #ifdef KVM_CAP_IRQ_ROUTING
 
@@ -1129,6 +1151,11 @@ struct kvm_x86_mce {
 #endif
 
 #ifdef KVM_CAP_XEN_HVM
+#define KVM_XEN_HVM_CONFIG_HYPERCALL_MSR	(1 << 0)
+#define KVM_XEN_HVM_CONFIG_INTERCEPT_HCALL	(1 << 1)
+#define KVM_XEN_HVM_CONFIG_SHARED_INFO		(1 << 2)
+#define KVM_XEN_HVM_CONFIG_RUNSTATE		(1 << 3)
+
 struct kvm_xen_hvm_config {
 	__u32 flags;
 	__u32 msr;
@@ -1563,6 +1590,57 @@ struct kvm_pv_cmd {
 /* Available with KVM_CAP_DIRTY_LOG_RING */
 #define KVM_RESET_DIRTY_RINGS		_IO(KVMIO, 0xc7)
 
+/* Per-VM Xen attributes */
+#define KVM_XEN_HVM_GET_ATTR	_IOWR(KVMIO, 0xc8, struct kvm_xen_hvm_attr)
+#define KVM_XEN_HVM_SET_ATTR	_IOW(KVMIO,  0xc9, struct kvm_xen_hvm_attr)
+
+struct kvm_xen_hvm_attr {
+	__u16 type;
+	__u16 pad[3];
+	union {
+		__u8 long_mode;
+		__u8 vector;
+		struct {
+			__u64 gfn;
+		} shared_info;
+		__u64 pad[8];
+	} u;
+};
+
+/* Available with KVM_CAP_XEN_HVM / KVM_XEN_HVM_CONFIG_SHARED_INFO */
+#define KVM_XEN_ATTR_TYPE_LONG_MODE		0x0
+#define KVM_XEN_ATTR_TYPE_SHARED_INFO		0x1
+#define KVM_XEN_ATTR_TYPE_UPCALL_VECTOR		0x2
+
+/* Per-vCPU Xen attributes */
+#define KVM_XEN_VCPU_GET_ATTR	_IOWR(KVMIO, 0xca, struct kvm_xen_vcpu_attr)
+#define KVM_XEN_VCPU_SET_ATTR	_IOW(KVMIO,  0xcb, struct kvm_xen_vcpu_attr)
+
+struct kvm_xen_vcpu_attr {
+	__u16 type;
+	__u16 pad[3];
+	union {
+		__u64 gpa;
+		__u64 pad[8];
+		struct {
+			__u64 state;
+			__u64 state_entry_time;
+			__u64 time_running;
+			__u64 time_runnable;
+			__u64 time_blocked;
+			__u64 time_offline;
+		} runstate;
+	} u;
+};
+
+/* Available with KVM_CAP_XEN_HVM / KVM_XEN_HVM_CONFIG_SHARED_INFO */
+#define KVM_XEN_VCPU_ATTR_TYPE_VCPU_INFO	0x0
+#define KVM_XEN_VCPU_ATTR_TYPE_VCPU_TIME_INFO	0x1
+#define KVM_XEN_VCPU_ATTR_TYPE_RUNSTATE_ADDR	0x2
+#define KVM_XEN_VCPU_ATTR_TYPE_RUNSTATE_CURRENT	0x3
+#define KVM_XEN_VCPU_ATTR_TYPE_RUNSTATE_DATA	0x4
+#define KVM_XEN_VCPU_ATTR_TYPE_RUNSTATE_ADJUST	0x5
+
 /* Secure Encrypted Virtualization command */
 enum sev_cmd_id {
 	/* Guest initialization commands */
@@ -1591,6 +1669,8 @@ enum sev_cmd_id {
 	KVM_SEV_DBG_ENCRYPT,
 	/* Guest certificates commands */
 	KVM_SEV_CERT_EXPORT,
+	/* Attestation report */
+	KVM_SEV_GET_ATTESTATION_REPORT,
 
 	KVM_SEV_NR_MAX,
 };
@@ -1643,6 +1723,12 @@ struct kvm_sev_dbg {
 	__u32 len;
 };
 
+struct kvm_sev_attestation_report {
+	__u8 mnonce[16];
+	__u64 uaddr;
+	__u32 len;
+};
+
 #define KVM_DEV_ASSIGN_ENABLE_IOMMU	(1 << 0)
 #define KVM_DEV_ASSIGN_PCI_2_3		(1 << 1)
 #define KVM_DEV_ASSIGN_MASK_INTX	(1 << 2)
@@ -1764,4 +1850,7 @@ struct kvm_dirty_gfn {
 	__u64 offset;
 };
 
+#define KVM_BUS_LOCK_DETECTION_OFF             (1 << 0)
+#define KVM_BUS_LOCK_DETECTION_EXIT            (1 << 1)
+
 #endif /* __LINUX_KVM_H */
diff --git a/linux-headers/linux/vfio.h b/linux-headers/linux/vfio.h
index 609099e455cd..e38a48840306 100644
--- a/linux-headers/linux/vfio.h
+++ b/linux-headers/linux/vfio.h
@@ -46,6 +46,12 @@
  */
 #define VFIO_NOIOMMU_IOMMU		8
 
+/* Supports VFIO_DMA_UNMAP_FLAG_ALL */
+#define VFIO_UNMAP_ALL			9
+
+/* Supports the vaddr flag for DMA map and unmap */
+#define VFIO_UPDATE_VADDR		10
+
 /*
  * The IOCTL interface is designed for extensibility by embedding the
  * structure length (argsz) and flags into structures passed between
@@ -1074,12 +1080,22 @@ struct vfio_iommu_type1_info_dma_avail {
  *
  * Map process virtual addresses to IO virtual addresses using the
  * provided struct vfio_dma_map. Caller sets argsz. READ &/ WRITE required.
+ *
+ * If flags & VFIO_DMA_MAP_FLAG_VADDR, update the base vaddr for iova, and
+ * unblock translation of host virtual addresses in the iova range.  The vaddr
+ * must have previously been invalidated with VFIO_DMA_UNMAP_FLAG_VADDR.  To
+ * maintain memory consistency within the user application, the updated vaddr
+ * must address the same memory object as originally mapped.  Failure to do so
+ * will result in user memory corruption and/or device misbehavior.  iova and
+ * size must match those in the original MAP_DMA call.  Protection is not
+ * changed, and the READ & WRITE flags must be 0.
  */
 struct vfio_iommu_type1_dma_map {
 	__u32	argsz;
 	__u32	flags;
 #define VFIO_DMA_MAP_FLAG_READ (1 << 0)		/* readable from device */
 #define VFIO_DMA_MAP_FLAG_WRITE (1 << 1)	/* writable from device */
+#define VFIO_DMA_MAP_FLAG_VADDR (1 << 2)
 	__u64	vaddr;				/* Process virtual address */
 	__u64	iova;				/* IO virtual address */
 	__u64	size;				/* Size of mapping (bytes) */
@@ -1102,6 +1118,7 @@ struct vfio_bitmap {
  * field.  No guarantee is made to the user that arbitrary unmaps of iova
  * or size different from those used in the original mapping call will
  * succeed.
+ *
  * VFIO_DMA_UNMAP_FLAG_GET_DIRTY_BITMAP should be set to get the dirty bitmap
  * before unmapping IO virtual addresses. When this flag is set, the user must
  * provide a struct vfio_bitmap in data[]. User must provide zero-allocated
@@ -1111,11 +1128,21 @@ struct vfio_bitmap {
  * indicates that the page at that offset from iova is dirty. A Bitmap of the
  * pages in the range of unmapped size is returned in the user-provided
  * vfio_bitmap.data.
+ *
+ * If flags & VFIO_DMA_UNMAP_FLAG_ALL, unmap all addresses.  iova and size
+ * must be 0.  This cannot be combined with the get-dirty-bitmap flag.
+ *
+ * If flags & VFIO_DMA_UNMAP_FLAG_VADDR, do not unmap, but invalidate host
+ * virtual addresses in the iova range.  Tasks that attempt to translate an
+ * iova's vaddr will block.  DMA to already-mapped pages continues.  This
+ * cannot be combined with the get-dirty-bitmap flag.
  */
 struct vfio_iommu_type1_dma_unmap {
 	__u32	argsz;
 	__u32	flags;
 #define VFIO_DMA_UNMAP_FLAG_GET_DIRTY_BITMAP (1 << 0)
+#define VFIO_DMA_UNMAP_FLAG_ALL		     (1 << 1)
+#define VFIO_DMA_UNMAP_FLAG_VADDR	     (1 << 2)
 	__u64	iova;				/* IO virtual address */
 	__u64	size;				/* Size of mapping (bytes) */
 	__u8    data[];
-- 
2.26.3

[for-6.1 2/2] virtiofsd: Add support for FUSE_SYNCFS request

[Greg Kurz]

Honor the expected behavior of syncfs() to synchronously flush all
data and metadata on linux systems. Like the ->sync_fs() superblock
operation in the linux kernel, FUSE_SYNCFS has a 'wait' argument that
tells whether the server should wait for outstanding I/Os to complete
before replying to the client. Anything virtiofsd can do to flush
the caches implies blocking syscalls, so nothing is done if waiting
isn't requested.

Flushing is done with syncfs(). This is suboptimal as it will also
flush writes performed by any other process on the same file system,
and thus add an unbounded time penalty to syncfs(). This may be
optimized in the future, but enforce correctness first.

Signed-off-by: Greg Kurz <groug@kaod.org>
---
 tools/virtiofsd/fuse_lowlevel.c       | 19 ++++++++++++++++++
 tools/virtiofsd/fuse_lowlevel.h       | 13 ++++++++++++
 tools/virtiofsd/passthrough_ll.c      | 29 +++++++++++++++++++++++++++
 tools/virtiofsd/passthrough_seccomp.c |  1 +
 4 files changed, 62 insertions(+)

diff --git a/tools/virtiofsd/fuse_lowlevel.c b/tools/virtiofsd/fuse_lowlevel.c
index 58e32fc96369..2d0c47a7a60e 100644
--- a/tools/virtiofsd/fuse_lowlevel.c
+++ b/tools/virtiofsd/fuse_lowlevel.c
@@ -1870,6 +1870,24 @@ static void do_lseek(fuse_req_t req, fuse_ino_t nodeid,
     }
 }
 
+static void do_syncfs(fuse_req_t req, fuse_ino_t nodeid,
+                      struct fuse_mbuf_iter *iter)
+{
+    struct fuse_syncfs_in *arg;
+
+    arg = fuse_mbuf_iter_advance(iter, sizeof(*arg));
+    if (!arg) {
+        fuse_reply_err(req, EINVAL);
+        return;
+    }
+
+    if (req->se->op.syncfs) {
+        req->se->op.syncfs(req, arg->wait);
+    } else {
+        fuse_reply_err(req, ENOSYS);
+    }
+}
+
 static void do_init(fuse_req_t req, fuse_ino_t nodeid,
                     struct fuse_mbuf_iter *iter)
 {
@@ -2267,6 +2285,7 @@ static struct {
     [FUSE_RENAME2] = { do_rename2, "RENAME2" },
     [FUSE_COPY_FILE_RANGE] = { do_copy_file_range, "COPY_FILE_RANGE" },
     [FUSE_LSEEK] = { do_lseek, "LSEEK" },
+    [FUSE_SYNCFS] = { do_syncfs, "SYNCFS" },
 };
 
 #define FUSE_MAXOP (sizeof(fuse_ll_ops) / sizeof(fuse_ll_ops[0]))
diff --git a/tools/virtiofsd/fuse_lowlevel.h b/tools/virtiofsd/fuse_lowlevel.h
index 3bf786b03485..b5ac42c31799 100644
--- a/tools/virtiofsd/fuse_lowlevel.h
+++ b/tools/virtiofsd/fuse_lowlevel.h
@@ -1225,6 +1225,19 @@ struct fuse_lowlevel_ops {
      */
     void (*lseek)(fuse_req_t req, fuse_ino_t ino, off_t off, int whence,
                   struct fuse_file_info *fi);
+
+    /**
+     * Synchronize file system content
+     *
+     * If this request is answered with an error code of ENOSYS,
+     * this is treated as success and future calls to syncfs() will
+     * succeed automatically without being sent to the filesystem
+     * process.
+     *
+     * @param req request handle
+     * @param wait whether to wait for outstanding I/Os to complete
+     */
+    void (*syncfs)(fuse_req_t req, int wait);
 };
 
 /**
diff --git a/tools/virtiofsd/passthrough_ll.c b/tools/virtiofsd/passthrough_ll.c
index 1553d2ef454f..6b66f3208be0 100644
--- a/tools/virtiofsd/passthrough_ll.c
+++ b/tools/virtiofsd/passthrough_ll.c
@@ -3124,6 +3124,34 @@ static void lo_lseek(fuse_req_t req, fuse_ino_t ino, off_t off, int whence,
     }
 }
 
+static void lo_syncfs(fuse_req_t req, int wait)
+{
+    if (wait) {
+        struct lo_data *lo = lo_data(req);
+        int fd, ret;
+
+        fd = lo_inode_open(lo, &lo->root, O_RDONLY);
+        if (fd < 0) {
+            fuse_reply_err(req, errno);
+            return;
+        }
+
+        /*
+         * FIXME: this is suboptimal because it will also flush unrelated
+         *        writes not coming from the client. This can dramatically
+         *        increase the time spent in syncfs() if some process is
+         *        writing lots of data on the same filesystem as virtiofsd.
+         */
+        ret = syncfs(fd);
+        /* syncfs() never fails on a valid fd */
+        assert(ret == 0);
+
+        close(fd);
+    }
+
+    fuse_reply_err(req, 0);
+}
+
 static void lo_destroy(void *userdata)
 {
     struct lo_data *lo = (struct lo_data *)userdata;
@@ -3184,6 +3212,7 @@ static struct fuse_lowlevel_ops lo_oper = {
     .copy_file_range = lo_copy_file_range,
 #endif
     .lseek = lo_lseek,
+    .syncfs = lo_syncfs,
     .destroy = lo_destroy,
 };
 
diff --git a/tools/virtiofsd/passthrough_seccomp.c b/tools/virtiofsd/passthrough_seccomp.c
index 62441cfcdb95..343188447901 100644
--- a/tools/virtiofsd/passthrough_seccomp.c
+++ b/tools/virtiofsd/passthrough_seccomp.c
@@ -107,6 +107,7 @@ static const int syscall_allowlist[] = {
     SCMP_SYS(set_robust_list),
     SCMP_SYS(setxattr),
     SCMP_SYS(symlinkat),
+    SCMP_SYS(syncfs),
     SCMP_SYS(time), /* Rarely needed, except on static builds */
     SCMP_SYS(tgkill),
     SCMP_SYS(unlinkat),
-- 
2.26.3

Re: [Virtio-fs] [for-6.1 2/2] virtiofsd: Add support for FUSE_SYNCFS request

[Vivek Goyal]

On Mon, Apr 19, 2021 at 05:11:42PM +0200, Greg Kurz wrote:
> Honor the expected behavior of syncfs() to synchronously flush all
> data and metadata on linux systems. Like the ->sync_fs() superblock
> operation in the linux kernel, FUSE_SYNCFS has a 'wait' argument that
> tells whether the server should wait for outstanding I/Os to complete
> before replying to the client. Anything virtiofsd can do to flush
> the caches implies blocking syscalls, so nothing is done if waiting
> isn't requested.
> 
> Flushing is done with syncfs(). This is suboptimal as it will also
> flush writes performed by any other process on the same file system,
> and thus add an unbounded time penalty to syncfs(). This may be
> optimized in the future, but enforce correctness first.
> 
> Signed-off-by: Greg Kurz <groug@kaod.org>
> ---
>  tools/virtiofsd/fuse_lowlevel.c       | 19 ++++++++++++++++++
>  tools/virtiofsd/fuse_lowlevel.h       | 13 ++++++++++++
>  tools/virtiofsd/passthrough_ll.c      | 29 +++++++++++++++++++++++++++
>  tools/virtiofsd/passthrough_seccomp.c |  1 +
>  4 files changed, 62 insertions(+)
> 
> diff --git a/tools/virtiofsd/fuse_lowlevel.c b/tools/virtiofsd/fuse_lowlevel.c
> index 58e32fc96369..2d0c47a7a60e 100644
> --- a/tools/virtiofsd/fuse_lowlevel.c
> +++ b/tools/virtiofsd/fuse_lowlevel.c
> @@ -1870,6 +1870,24 @@ static void do_lseek(fuse_req_t req, fuse_ino_t nodeid,
>      }
>  }
>  
> +static void do_syncfs(fuse_req_t req, fuse_ino_t nodeid,
> +                      struct fuse_mbuf_iter *iter)
> +{
> +    struct fuse_syncfs_in *arg;
> +
> +    arg = fuse_mbuf_iter_advance(iter, sizeof(*arg));
> +    if (!arg) {
> +        fuse_reply_err(req, EINVAL);
> +        return;
> +    }
> +
> +    if (req->se->op.syncfs) {
> +        req->se->op.syncfs(req, arg->wait);
> +    } else {
> +        fuse_reply_err(req, ENOSYS);
> +    }
> +}
> +
>  static void do_init(fuse_req_t req, fuse_ino_t nodeid,
>                      struct fuse_mbuf_iter *iter)
>  {
> @@ -2267,6 +2285,7 @@ static struct {
>      [FUSE_RENAME2] = { do_rename2, "RENAME2" },
>      [FUSE_COPY_FILE_RANGE] = { do_copy_file_range, "COPY_FILE_RANGE" },
>      [FUSE_LSEEK] = { do_lseek, "LSEEK" },
> +    [FUSE_SYNCFS] = { do_syncfs, "SYNCFS" },
>  };
>  
>  #define FUSE_MAXOP (sizeof(fuse_ll_ops) / sizeof(fuse_ll_ops[0]))
> diff --git a/tools/virtiofsd/fuse_lowlevel.h b/tools/virtiofsd/fuse_lowlevel.h
> index 3bf786b03485..b5ac42c31799 100644
> --- a/tools/virtiofsd/fuse_lowlevel.h
> +++ b/tools/virtiofsd/fuse_lowlevel.h
> @@ -1225,6 +1225,19 @@ struct fuse_lowlevel_ops {
>       */
>      void (*lseek)(fuse_req_t req, fuse_ino_t ino, off_t off, int whence,
>                    struct fuse_file_info *fi);
> +
> +    /**
> +     * Synchronize file system content
> +     *
> +     * If this request is answered with an error code of ENOSYS,
> +     * this is treated as success and future calls to syncfs() will
> +     * succeed automatically without being sent to the filesystem
> +     * process.
> +     *
> +     * @param req request handle
> +     * @param wait whether to wait for outstanding I/Os to complete
> +     */
> +    void (*syncfs)(fuse_req_t req, int wait);
>  };
>  
>  /**
> diff --git a/tools/virtiofsd/passthrough_ll.c b/tools/virtiofsd/passthrough_ll.c
> index 1553d2ef454f..6b66f3208be0 100644
> --- a/tools/virtiofsd/passthrough_ll.c
> +++ b/tools/virtiofsd/passthrough_ll.c
> @@ -3124,6 +3124,34 @@ static void lo_lseek(fuse_req_t req, fuse_ino_t ino, off_t off, int whence,
>      }
>  }
>  
> +static void lo_syncfs(fuse_req_t req, int wait)
> +{
> +    if (wait) {
> +        struct lo_data *lo = lo_data(req);
> +        int fd, ret;
> +
> +        fd = lo_inode_open(lo, &lo->root, O_RDONLY);
> +        if (fd < 0) {
> +            fuse_reply_err(req, errno);
> +            return;
> +        }
> +
> +        /*
> +         * FIXME: this is suboptimal because it will also flush unrelated
> +         *        writes not coming from the client. This can dramatically
> +         *        increase the time spent in syncfs() if some process is
> +         *        writing lots of data on the same filesystem as virtiofsd.
> +         */
> +        ret = syncfs(fd);
> +        /* syncfs() never fails on a valid fd */

Where does this come from. man page says.

       syncfs() can fail for at least the following reason:

       EBADF  fd is not a valid file descriptor.

It says "can fail for at least the following reason". Its not ruling out
failures due to other reasons?

Also kernel implementation of syscall is as follows.

SYSCALL_DEFINE1(syncfs, int, fd)
{
	if (!f.file)
                return -EBADF;
        sb = f.file->f_path.dentry->d_sb;

        down_read(&sb->s_umount);
        ret = sync_filesystem(sb);
        up_read(&sb->s_umount);

        ret2 = errseq_check_and_advance(&sb->s_wb_err, &f.file->f_sb_err);

        fdput(f);
        return ret ? ret : ret2;
}

So it explicityly capture error code from sync_filesystem() and 
errseq_check_and_advance() and returns one of them.

> +        assert(ret == 0);
> +
> +        close(fd);
> +    }
> +
> +    fuse_reply_err(req, 0);

This probably could be better strucutred as.


	if (!wait)
		goto out;

	/* Rest of the logic to call syncfs() */
out:
	fuse_reply_err(req, ret);

Vivek

> +}

> +
>  static void lo_destroy(void *userdata)
>  {
>      struct lo_data *lo = (struct lo_data *)userdata;
> @@ -3184,6 +3212,7 @@ static struct fuse_lowlevel_ops lo_oper = {
>      .copy_file_range = lo_copy_file_range,
>  #endif
>      .lseek = lo_lseek,
> +    .syncfs = lo_syncfs,
>      .destroy = lo_destroy,
>  };
>  
> diff --git a/tools/virtiofsd/passthrough_seccomp.c b/tools/virtiofsd/passthrough_seccomp.c
> index 62441cfcdb95..343188447901 100644
> --- a/tools/virtiofsd/passthrough_seccomp.c
> +++ b/tools/virtiofsd/passthrough_seccomp.c
> @@ -107,6 +107,7 @@ static const int syscall_allowlist[] = {
>      SCMP_SYS(set_robust_list),
>      SCMP_SYS(setxattr),
>      SCMP_SYS(symlinkat),
> +    SCMP_SYS(syncfs),
>      SCMP_SYS(time), /* Rarely needed, except on static builds */
>      SCMP_SYS(tgkill),
>      SCMP_SYS(unlinkat),
> -- 
> 2.26.3
> 
> _______________________________________________
> Virtio-fs mailing list
> Virtio-fs@redhat.com
> https://listman.redhat.com/mailman/listinfo/virtio-fs

Re: [Virtio-fs] [for-6.1 2/2] virtiofsd: Add support for FUSE_SYNCFS request

[Greg Kurz]

On Tue, 20 Apr 2021 14:57:19 -0400
Vivek Goyal <vgoyal@redhat.com> wrote:

> On Mon, Apr 19, 2021 at 05:11:42PM +0200, Greg Kurz wrote:
> > Honor the expected behavior of syncfs() to synchronously flush all
> > data and metadata on linux systems. Like the ->sync_fs() superblock
> > operation in the linux kernel, FUSE_SYNCFS has a 'wait' argument that
> > tells whether the server should wait for outstanding I/Os to complete
> > before replying to the client. Anything virtiofsd can do to flush
> > the caches implies blocking syscalls, so nothing is done if waiting
> > isn't requested.
> > 
> > Flushing is done with syncfs(). This is suboptimal as it will also
> > flush writes performed by any other process on the same file system,
> > and thus add an unbounded time penalty to syncfs(). This may be
> > optimized in the future, but enforce correctness first.
> > 
> > Signed-off-by: Greg Kurz <groug@kaod.org>
> > ---
> >  tools/virtiofsd/fuse_lowlevel.c       | 19 ++++++++++++++++++
> >  tools/virtiofsd/fuse_lowlevel.h       | 13 ++++++++++++
> >  tools/virtiofsd/passthrough_ll.c      | 29 +++++++++++++++++++++++++++
> >  tools/virtiofsd/passthrough_seccomp.c |  1 +
> >  4 files changed, 62 insertions(+)
> > 
> > diff --git a/tools/virtiofsd/fuse_lowlevel.c b/tools/virtiofsd/fuse_lowlevel.c
> > index 58e32fc96369..2d0c47a7a60e 100644
> > --- a/tools/virtiofsd/fuse_lowlevel.c
> > +++ b/tools/virtiofsd/fuse_lowlevel.c
> > @@ -1870,6 +1870,24 @@ static void do_lseek(fuse_req_t req, fuse_ino_t nodeid,
> >      }
> >  }
> >  
> > +static void do_syncfs(fuse_req_t req, fuse_ino_t nodeid,
> > +                      struct fuse_mbuf_iter *iter)
> > +{
> > +    struct fuse_syncfs_in *arg;
> > +
> > +    arg = fuse_mbuf_iter_advance(iter, sizeof(*arg));
> > +    if (!arg) {
> > +        fuse_reply_err(req, EINVAL);
> > +        return;
> > +    }
> > +
> > +    if (req->se->op.syncfs) {
> > +        req->se->op.syncfs(req, arg->wait);
> > +    } else {
> > +        fuse_reply_err(req, ENOSYS);
> > +    }
> > +}
> > +
> >  static void do_init(fuse_req_t req, fuse_ino_t nodeid,
> >                      struct fuse_mbuf_iter *iter)
> >  {
> > @@ -2267,6 +2285,7 @@ static struct {
> >      [FUSE_RENAME2] = { do_rename2, "RENAME2" },
> >      [FUSE_COPY_FILE_RANGE] = { do_copy_file_range, "COPY_FILE_RANGE" },
> >      [FUSE_LSEEK] = { do_lseek, "LSEEK" },
> > +    [FUSE_SYNCFS] = { do_syncfs, "SYNCFS" },
> >  };
> >  
> >  #define FUSE_MAXOP (sizeof(fuse_ll_ops) / sizeof(fuse_ll_ops[0]))
> > diff --git a/tools/virtiofsd/fuse_lowlevel.h b/tools/virtiofsd/fuse_lowlevel.h
> > index 3bf786b03485..b5ac42c31799 100644
> > --- a/tools/virtiofsd/fuse_lowlevel.h
> > +++ b/tools/virtiofsd/fuse_lowlevel.h
> > @@ -1225,6 +1225,19 @@ struct fuse_lowlevel_ops {
> >       */
> >      void (*lseek)(fuse_req_t req, fuse_ino_t ino, off_t off, int whence,
> >                    struct fuse_file_info *fi);
> > +
> > +    /**
> > +     * Synchronize file system content
> > +     *
> > +     * If this request is answered with an error code of ENOSYS,
> > +     * this is treated as success and future calls to syncfs() will
> > +     * succeed automatically without being sent to the filesystem
> > +     * process.
> > +     *
> > +     * @param req request handle
> > +     * @param wait whether to wait for outstanding I/Os to complete
> > +     */
> > +    void (*syncfs)(fuse_req_t req, int wait);
> >  };
> >  
> >  /**
> > diff --git a/tools/virtiofsd/passthrough_ll.c b/tools/virtiofsd/passthrough_ll.c
> > index 1553d2ef454f..6b66f3208be0 100644
> > --- a/tools/virtiofsd/passthrough_ll.c
> > +++ b/tools/virtiofsd/passthrough_ll.c
> > @@ -3124,6 +3124,34 @@ static void lo_lseek(fuse_req_t req, fuse_ino_t ino, off_t off, int whence,
> >      }
> >  }
> >  
> > +static void lo_syncfs(fuse_req_t req, int wait)
> > +{
> > +    if (wait) {
> > +        struct lo_data *lo = lo_data(req);
> > +        int fd, ret;
> > +
> > +        fd = lo_inode_open(lo, &lo->root, O_RDONLY);
> > +        if (fd < 0) {
> > +            fuse_reply_err(req, errno);
> > +            return;
> > +        }
> > +
> > +        /*
> > +         * FIXME: this is suboptimal because it will also flush unrelated
> > +         *        writes not coming from the client. This can dramatically
> > +         *        increase the time spent in syncfs() if some process is
> > +         *        writing lots of data on the same filesystem as virtiofsd.
> > +         */
> > +        ret = syncfs(fd);
> > +        /* syncfs() never fails on a valid fd */
> 
> Where does this come from. man page says.
> 
>        syncfs() can fail for at least the following reason:
> 
>        EBADF  fd is not a valid file descriptor.
> 
> It says "can fail for at least the following reason". Its not ruling out
> failures due to other reasons?
> 
> Also kernel implementation of syscall is as follows.
> 
> SYSCALL_DEFINE1(syncfs, int, fd)
> {
> 	if (!f.file)
>                 return -EBADF;
>         sb = f.file->f_path.dentry->d_sb;
> 
>         down_read(&sb->s_umount);
>         ret = sync_filesystem(sb);
>         up_read(&sb->s_umount);
> 
>         ret2 = errseq_check_and_advance(&sb->s_wb_err, &f.file->f_sb_err);
> 
>         fdput(f);
>         return ret ? ret : ret2;
> }
> 
> So it explicityly capture error code from sync_filesystem() and 
> errseq_check_and_advance() and returns one of them.
> 

You're right. I'll drop the assert() and propagate the
error code.

> > +        assert(ret == 0);
> > +
> > +        close(fd);
> > +    }
> > +
> > +    fuse_reply_err(req, 0);
> 
> This probably could be better strucutred as.
> 
> 
> 	if (!wait)
> 		goto out;
> 
> 	/* Rest of the logic to call syncfs() */
> out:
> 	fuse_reply_err(req, ret);
> 

Will do.

> Vivek
> 

Cheers,

--
Greg

> > +}
> 
> > +
> >  static void lo_destroy(void *userdata)
> >  {
> >      struct lo_data *lo = (struct lo_data *)userdata;
> > @@ -3184,6 +3212,7 @@ static struct fuse_lowlevel_ops lo_oper = {
> >      .copy_file_range = lo_copy_file_range,
> >  #endif
> >      .lseek = lo_lseek,
> > +    .syncfs = lo_syncfs,
> >      .destroy = lo_destroy,
> >  };
> >  
> > diff --git a/tools/virtiofsd/passthrough_seccomp.c b/tools/virtiofsd/passthrough_seccomp.c
> > index 62441cfcdb95..343188447901 100644
> > --- a/tools/virtiofsd/passthrough_seccomp.c
> > +++ b/tools/virtiofsd/passthrough_seccomp.c
> > @@ -107,6 +107,7 @@ static const int syscall_allowlist[] = {
> >      SCMP_SYS(set_robust_list),
> >      SCMP_SYS(setxattr),
> >      SCMP_SYS(symlinkat),
> > +    SCMP_SYS(syncfs),
> >      SCMP_SYS(time), /* Rarely needed, except on static builds */
> >      SCMP_SYS(tgkill),
> >      SCMP_SYS(unlinkat),
> > -- 
> > 2.26.3
> > 
> > _______________________________________________
> > Virtio-fs mailing list
> > Virtio-fs@redhat.com
> > https://listman.redhat.com/mailman/listinfo/virtio-fs
>