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Greg Kroah-Hartman e51ef120e8 Merge 4.9.233 into android-4.9-q
Changes in 4.9.233
	xfs: catch inode allocation state mismatch corruption
	xfs: validate cached inodes are free when allocated
	xfs: don't call xfs_da_shrink_inode with NULL bp
	net: phy: mdio-bcm-unimac: fix potential NULL dereference in unimac_mdio_probe()
	crypto: ccp - Release all allocated memory if sha type is invalid
	media: rc: prevent memory leak in cx23888_ir_probe
	ath9k_htc: release allocated buffer if timed out
	ath9k: release allocated buffer if timed out
	PCI/ASPM: Disable ASPM on ASMedia ASM1083/1085 PCIe-to-PCI bridge
	ARM: 8986/1: hw_breakpoint: Don't invoke overflow handler on uaccess watchpoints
	drm/amdgpu: Prevent kernel-infoleak in amdgpu_info_ioctl()
	drm: hold gem reference until object is no longer accessed
	f2fs: check memory boundary by insane namelen
	f2fs: check if file namelen exceeds max value
	9p/trans_fd: abort p9_read_work if req status changed
	9p/trans_fd: Fix concurrency del of req_list in p9_fd_cancelled/p9_read_work
	x86/build/lto: Fix truncated .bss with -fdata-sections
	x86, vmlinux.lds: Page-align end of ..page_aligned sections
	fbdev: Detect integer underflow at "struct fbcon_ops"->clear_margins.
	rds: Prevent kernel-infoleak in rds_notify_queue_get()
	xfs: fix missed wakeup on l_flush_wait
	uapi: includes linux/types.h before exporting files
	install several missing uapi headers
	net/x25: Fix x25_neigh refcnt leak when x25 disconnect
	net/x25: Fix null-ptr-deref in x25_disconnect
	sh: Fix validation of system call number
	net: lan78xx: add missing endpoint sanity check
	net: lan78xx: fix transfer-buffer memory leak
	mlx4: disable device on shutdown
	mlxsw: core: Increase scope of RCU read-side critical section
	mlxsw: core: Free EMAD transactions using kfree_rcu()
	ibmvnic: Fix IRQ mapping disposal in error path
	mac80211: mesh: Free ie data when leaving mesh
	mac80211: mesh: Free pending skb when destroying a mpath
	arm64: csum: Fix handling of bad packets
	usb: hso: Fix debug compile warning on sparc32
	qed: Disable "MFW indication via attention" SPAM every 5 minutes
	nfc: s3fwrn5: add missing release on skb in s3fwrn5_recv_frame
	parisc: add support for cmpxchg on u8 pointers
	net: ethernet: ravb: exit if re-initialization fails in tx timeout
	Revert "i2c: cadence: Fix the hold bit setting"
	xen-netfront: fix potential deadlock in xennet_remove()
	KVM: LAPIC: Prevent setting the tscdeadline timer if the lapic is hw disabled
	x86/i8259: Use printk_deferred() to prevent deadlock
	random32: update the net random state on interrupt and activity
	ARM: percpu.h: fix build error
	random: fix circular include dependency on arm64 after addition of percpu.h
	random32: remove net_rand_state from the latent entropy gcc plugin
	random32: move the pseudo-random 32-bit definitions to prandom.h
	ext4: fix direct I/O read error
	USB: serial: qcserial: add EM7305 QDL product ID
	net/mlx5e: Don't support phys switch id if not in switchdev mode
	ALSA: seq: oss: Serialize ioctls
	Bluetooth: Fix slab-out-of-bounds read in hci_extended_inquiry_result_evt()
	Bluetooth: Prevent out-of-bounds read in hci_inquiry_result_evt()
	Bluetooth: Prevent out-of-bounds read in hci_inquiry_result_with_rssi_evt()
	omapfb: dss: Fix max fclk divider for omap36xx
	vgacon: Fix for missing check in scrollback handling
	mtd: properly check all write ioctls for permissions
	leds: wm831x-status: fix use-after-free on unbind
	leds: da903x: fix use-after-free on unbind
	leds: lm3533: fix use-after-free on unbind
	leds: 88pm860x: fix use-after-free on unbind
	net/9p: validate fds in p9_fd_open
	drm/nouveau/fbcon: fix module unload when fbcon init has failed for some reason
	cfg80211: check vendor command doit pointer before use
	igb: reinit_locked() should be called with rtnl_lock
	atm: fix atm_dev refcnt leaks in atmtcp_remove_persistent
	tools lib traceevent: Fix memory leak in process_dynamic_array_len
	xattr: break delegations in {set,remove}xattr
	binder: Prevent context manager from incrementing ref 0
	ipv4: Silence suspicious RCU usage warning
	ipv6: fix memory leaks on IPV6_ADDRFORM path
	vxlan: Ensure FDB dump is performed under RCU
	net: lan78xx: replace bogus endpoint lookup
	Revert "vxlan: fix tos value before xmit"
	usb: hso: check for return value in hso_serial_common_create()
	Smack: fix use-after-free in smk_write_relabel_self()
	tracepoint: Mark __tracepoint_string's __used
	gpio: fix oops resulting from calling of_get_named_gpio(NULL, ...)
	cgroup: add missing skcd->no_refcnt check in cgroup_sk_clone()
	EDAC: Fix reference count leaks
	arm64: dts: qcom: msm8916: Replace invalid bias-pull-none property
	arm64: dts: exynos: Fix silent hang after boot on Espresso
	m68k: mac: Don't send IOP message until channel is idle
	m68k: mac: Fix IOP status/control register writes
	platform/x86: intel-hid: Fix return value check in check_acpi_dev()
	platform/x86: intel-vbtn: Fix return value check in check_acpi_dev()
	ARM: at91: pm: add missing put_device() call in at91_pm_sram_init()
	ARM: socfpga: PM: add missing put_device() call in socfpga_setup_ocram_self_refresh()
	drm/tilcdc: fix leak & null ref in panel_connector_get_modes
	Bluetooth: add a mutex lock to avoid UAF in do_enale_set
	fs/btrfs: Add cond_resched() for try_release_extent_mapping() stalls
	drm/radeon: Fix reference count leaks caused by pm_runtime_get_sync
	video: fbdev: neofb: fix memory leak in neo_scan_monitor()
	md-cluster: fix wild pointer of unlock_all_bitmaps()
	drm/nouveau: fix multiple instances of reference count leaks
	drm/debugfs: fix plain echo to connector "force" attribute
	mm/mmap.c: Add cond_resched() for exit_mmap() CPU stalls
	brcmfmac: To fix Bss Info flag definition Bug
	iwlegacy: Check the return value of pcie_capability_read_*()
	usb: gadget: net2280: fix memory leak on probe error handling paths
	bdc: Fix bug causing crash after multiple disconnects
	dyndbg: fix a BUG_ON in ddebug_describe_flags
	bcache: fix super block seq numbers comparision in register_cache_set()
	ACPICA: Do not increment operation_region reference counts for field units
	agp/intel: Fix a memory leak on module initialisation failure
	video: fbdev: sm712fb: fix an issue about iounmap for a wrong address
	console: newport_con: fix an issue about leak related system resources
	video: pxafb: Fix the function used to balance a 'dma_alloc_coherent()' call
	iio: improve IIO_CONCENTRATION channel type description
	leds: lm355x: avoid enum conversion warning
	media: omap3isp: Add missed v4l2_ctrl_handler_free() for preview_init_entities()
	scsi: cumana_2: Fix different dev_id between request_irq() and free_irq()
	drm/mipi: use dcs write for mipi_dsi_dcs_set_tear_scanline
	cxl: Fix kobject memleak
	drm/radeon: fix array out-of-bounds read and write issues
	scsi: powertec: Fix different dev_id between request_irq() and free_irq()
	scsi: eesox: Fix different dev_id between request_irq() and free_irq()
	media: firewire: Using uninitialized values in node_probe()
	media: exynos4-is: Add missed check for pinctrl_lookup_state()
	xfs: fix reflink quota reservation accounting error
	PCI: Fix pci_cfg_wait queue locking problem
	leds: core: Flush scheduled work for system suspend
	drm: panel: simple: Fix bpc for LG LB070WV8 panel
	scsi: scsi_debug: Add check for sdebug_max_queue during module init
	mwifiex: Prevent memory corruption handling keys
	powerpc/vdso: Fix vdso cpu truncation
	staging: rtl8192u: fix a dubious looking mask before a shift
	PCI/ASPM: Add missing newline in sysfs 'policy'
	drm/imx: tve: fix regulator_disable error path
	USB: serial: iuu_phoenix: fix led-activity helpers
	usb: dwc2: Fix error path in gadget registration
	scsi: mesh: Fix panic after host or bus reset
	Smack: fix another vsscanf out of bounds
	Smack: prevent underflow in smk_set_cipso()
	power: supply: check if calc_soc succeeded in pm860x_init_battery
	selftests/powerpc: Fix CPU affinity for child process
	selftests/powerpc: Fix online CPU selection
	s390/qeth: don't process empty bridge port events
	wl1251: fix always return 0 error
	net: spider_net: Fix the size used in a 'dma_free_coherent()' call
	fsl/fman: use 32-bit unsigned integer
	fsl/fman: fix dereference null return value
	fsl/fman: fix unreachable code
	fsl/fman: check dereferencing null pointer
	fsl/fman: fix eth hash table allocation
	dlm: Fix kobject memleak
	pinctrl-single: fix pcs_parse_pinconf() return value
	drivers/net/wan/lapbether: Added needed_headroom and a skb->len check
	net/nfc/rawsock.c: add CAP_NET_RAW check.
	net: Set fput_needed iff FDPUT_FPUT is set
	USB: serial: cp210x: re-enable auto-RTS on open
	USB: serial: cp210x: enable usb generic throttle/unthrottle
	ALSA: usb-audio: Creative USB X-Fi Pro SB1095 volume knob support
	ALSA: usb-audio: fix overeager device match for MacroSilicon MS2109
	ALSA: usb-audio: add quirk for Pioneer DDJ-RB
	crypto: qat - fix double free in qat_uclo_create_batch_init_list
	crypto: ccp - Fix use of merged scatterlists
	fs/minix: check return value of sb_getblk()
	fs/minix: don't allow getting deleted inodes
	fs/minix: reject too-large maximum file size
	ALSA: usb-audio: work around streaming quirk for MacroSilicon MS2109
	9p: Fix memory leak in v9fs_mount
	parisc: mask out enable and reserved bits from sba imask
	ARM: 8992/1: Fix unwind_frame for clang-built kernels
	xen/balloon: fix accounting in alloc_xenballooned_pages error path
	xen/balloon: make the balloon wait interruptible
	smb3: warn on confusing error scenario with sec=krb5
	PCI: hotplug: ACPI: Fix context refcounting in acpiphp_grab_context()
	btrfs: don't allocate anonymous block device for user invisible roots
	btrfs: only search for left_info if there is no right_info in try_merge_free_space
	btrfs: fix memory leaks after failure to lookup checksums during inode logging
	iio: dac: ad5592r: fix unbalanced mutex unlocks in ad5592r_read_raw()
	xtensa: fix xtensa_pmu_setup prototype
	powerpc: Fix circular dependency between percpu.h and mmu.h
	net: ethernet: stmmac: Disable hardware multicast filter
	net: stmmac: dwmac1000: provide multicast filter fallback
	net/compat: Add missing sock updates for SCM_RIGHTS
	md/raid5: Fix Force reconstruct-write io stuck in degraded raid5
	bcache: allocate meta data pages as compound pages
	mac80211: fix misplaced while instead of if
	MIPS: CPU#0 is not hotpluggable
	ext2: fix missing percpu_counter_inc
	ocfs2: change slot number type s16 to u16
	ftrace: Setup correct FTRACE_FL_REGS flags for module
	kprobes: Fix NULL pointer dereference at kprobe_ftrace_handler
	watchdog: f71808e_wdt: indicate WDIOF_CARDRESET support in watchdog_info.options
	watchdog: f71808e_wdt: remove use of wrong watchdog_info option
	watchdog: f71808e_wdt: clear watchdog timeout occurred flag
	pseries: Fix 64 bit logical memory block panic
	mfd: arizona: Ensure 32k clock is put on driver unbind and error
	USB: serial: ftdi_sio: make process-packet buffer unsigned
	USB: serial: ftdi_sio: clean up receive processing
	gpu: ipu-v3: image-convert: Combine rotate/no-rotate irq handlers
	iommu/omap: Check for failure of a call to omap_iommu_dump_ctx
	iommu/vt-d: Enforce PASID devTLB field mask
	i2c: rcar: slave: only send STOP event when we have been addressed
	clk: clk-atlas6: fix return value check in atlas6_clk_init()
	pwm: bcm-iproc: handle clk_get_rate() return
	Input: sentelic - fix error return when fsp_reg_write fails
	drm/vmwgfx: Fix two list_for_each loop exit tests
	net: qcom/emac: add missed clk_disable_unprepare in error path of emac_clks_phase1_init
	nfs: Fix getxattr kernel panic and memory overflow
	fs/ufs: avoid potential u32 multiplication overflow
	mfd: dln2: Run event handler loop under spinlock
	ALSA: echoaudio: Fix potential Oops in snd_echo_resume()
	sh: landisk: Add missing initialization of sh_io_port_base
	khugepaged: retract_page_tables() remember to test exit
	mm: Avoid calling build_all_zonelists_init under hotplug context
	Linux 4.9.233

Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
Change-Id: Ied62cb0768f5bd8e989d75e7c2ccf6f1e6f2efd4
2020-09-09 21:39:13 +03:00

1831 lines
48 KiB
C

/*
* Copyright (C) 2016 Oracle. All Rights Reserved.
*
* Author: Darrick J. Wong <darrick.wong@oracle.com>
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
*
* This program is distributed in the hope that it would be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA.
*/
#include "xfs.h"
#include "xfs_fs.h"
#include "xfs_shared.h"
#include "xfs_format.h"
#include "xfs_log_format.h"
#include "xfs_trans_resv.h"
#include "xfs_mount.h"
#include "xfs_defer.h"
#include "xfs_da_format.h"
#include "xfs_da_btree.h"
#include "xfs_inode.h"
#include "xfs_trans.h"
#include "xfs_inode_item.h"
#include "xfs_bmap.h"
#include "xfs_bmap_util.h"
#include "xfs_error.h"
#include "xfs_dir2.h"
#include "xfs_dir2_priv.h"
#include "xfs_ioctl.h"
#include "xfs_trace.h"
#include "xfs_log.h"
#include "xfs_icache.h"
#include "xfs_pnfs.h"
#include "xfs_btree.h"
#include "xfs_refcount_btree.h"
#include "xfs_refcount.h"
#include "xfs_bmap_btree.h"
#include "xfs_trans_space.h"
#include "xfs_bit.h"
#include "xfs_alloc.h"
#include "xfs_quota_defs.h"
#include "xfs_quota.h"
#include "xfs_btree.h"
#include "xfs_bmap_btree.h"
#include "xfs_reflink.h"
#include "xfs_iomap.h"
#include "xfs_rmap_btree.h"
#include "xfs_sb.h"
#include "xfs_ag_resv.h"
/*
* Copy on Write of Shared Blocks
*
* XFS must preserve "the usual" file semantics even when two files share
* the same physical blocks. This means that a write to one file must not
* alter the blocks in a different file; the way that we'll do that is
* through the use of a copy-on-write mechanism. At a high level, that
* means that when we want to write to a shared block, we allocate a new
* block, write the data to the new block, and if that succeeds we map the
* new block into the file.
*
* XFS provides a "delayed allocation" mechanism that defers the allocation
* of disk blocks to dirty-but-not-yet-mapped file blocks as long as
* possible. This reduces fragmentation by enabling the filesystem to ask
* for bigger chunks less often, which is exactly what we want for CoW.
*
* The delalloc mechanism begins when the kernel wants to make a block
* writable (write_begin or page_mkwrite). If the offset is not mapped, we
* create a delalloc mapping, which is a regular in-core extent, but without
* a real startblock. (For delalloc mappings, the startblock encodes both
* a flag that this is a delalloc mapping, and a worst-case estimate of how
* many blocks might be required to put the mapping into the BMBT.) delalloc
* mappings are a reservation against the free space in the filesystem;
* adjacent mappings can also be combined into fewer larger mappings.
*
* As an optimization, the CoW extent size hint (cowextsz) creates
* outsized aligned delalloc reservations in the hope of landing out of
* order nearby CoW writes in a single extent on disk, thereby reducing
* fragmentation and improving future performance.
*
* D: --RRRRRRSSSRRRRRRRR--- (data fork)
* C: ------DDDDDDD--------- (CoW fork)
*
* When dirty pages are being written out (typically in writepage), the
* delalloc reservations are converted into unwritten mappings by
* allocating blocks and replacing the delalloc mapping with real ones.
* A delalloc mapping can be replaced by several unwritten ones if the
* free space is fragmented.
*
* D: --RRRRRRSSSRRRRRRRR---
* C: ------UUUUUUU---------
*
* We want to adapt the delalloc mechanism for copy-on-write, since the
* write paths are similar. The first two steps (creating the reservation
* and allocating the blocks) are exactly the same as delalloc except that
* the mappings must be stored in a separate CoW fork because we do not want
* to disturb the mapping in the data fork until we're sure that the write
* succeeded. IO completion in this case is the process of removing the old
* mapping from the data fork and moving the new mapping from the CoW fork to
* the data fork. This will be discussed shortly.
*
* For now, unaligned directio writes will be bounced back to the page cache.
* Block-aligned directio writes will use the same mechanism as buffered
* writes.
*
* Just prior to submitting the actual disk write requests, we convert
* the extents representing the range of the file actually being written
* (as opposed to extra pieces created for the cowextsize hint) to real
* extents. This will become important in the next step:
*
* D: --RRRRRRSSSRRRRRRRR---
* C: ------UUrrUUU---------
*
* CoW remapping must be done after the data block write completes,
* because we don't want to destroy the old data fork map until we're sure
* the new block has been written. Since the new mappings are kept in a
* separate fork, we can simply iterate these mappings to find the ones
* that cover the file blocks that we just CoW'd. For each extent, simply
* unmap the corresponding range in the data fork, map the new range into
* the data fork, and remove the extent from the CoW fork. Because of
* the presence of the cowextsize hint, however, we must be careful
* only to remap the blocks that we've actually written out -- we must
* never remap delalloc reservations nor CoW staging blocks that have
* yet to be written. This corresponds exactly to the real extents in
* the CoW fork:
*
* D: --RRRRRRrrSRRRRRRRR---
* C: ------UU--UUU---------
*
* Since the remapping operation can be applied to an arbitrary file
* range, we record the need for the remap step as a flag in the ioend
* instead of declaring a new IO type. This is required for direct io
* because we only have ioend for the whole dio, and we have to be able to
* remember the presence of unwritten blocks and CoW blocks with a single
* ioend structure. Better yet, the more ground we can cover with one
* ioend, the better.
*/
/*
* Given an AG extent, find the lowest-numbered run of shared blocks
* within that range and return the range in fbno/flen. If
* find_end_of_shared is true, return the longest contiguous extent of
* shared blocks. If there are no shared extents, fbno and flen will
* be set to NULLAGBLOCK and 0, respectively.
*/
int
xfs_reflink_find_shared(
struct xfs_mount *mp,
xfs_agnumber_t agno,
xfs_agblock_t agbno,
xfs_extlen_t aglen,
xfs_agblock_t *fbno,
xfs_extlen_t *flen,
bool find_end_of_shared)
{
struct xfs_buf *agbp;
struct xfs_btree_cur *cur;
int error;
error = xfs_alloc_read_agf(mp, NULL, agno, 0, &agbp);
if (error)
return error;
if (!agbp)
return -ENOMEM;
cur = xfs_refcountbt_init_cursor(mp, NULL, agbp, agno, NULL);
error = xfs_refcount_find_shared(cur, agbno, aglen, fbno, flen,
find_end_of_shared);
xfs_btree_del_cursor(cur, error ? XFS_BTREE_ERROR : XFS_BTREE_NOERROR);
xfs_buf_relse(agbp);
return error;
}
/*
* Trim the mapping to the next block where there's a change in the
* shared/unshared status. More specifically, this means that we
* find the lowest-numbered extent of shared blocks that coincides with
* the given block mapping. If the shared extent overlaps the start of
* the mapping, trim the mapping to the end of the shared extent. If
* the shared region intersects the mapping, trim the mapping to the
* start of the shared extent. If there are no shared regions that
* overlap, just return the original extent.
*/
int
xfs_reflink_trim_around_shared(
struct xfs_inode *ip,
struct xfs_bmbt_irec *irec,
bool *shared,
bool *trimmed)
{
xfs_agnumber_t agno;
xfs_agblock_t agbno;
xfs_extlen_t aglen;
xfs_agblock_t fbno;
xfs_extlen_t flen;
int error = 0;
/* Holes, unwritten, and delalloc extents cannot be shared */
if (!xfs_is_reflink_inode(ip) ||
ISUNWRITTEN(irec) ||
irec->br_startblock == HOLESTARTBLOCK ||
irec->br_startblock == DELAYSTARTBLOCK ||
isnullstartblock(irec->br_startblock)) {
*shared = false;
return 0;
}
trace_xfs_reflink_trim_around_shared(ip, irec);
agno = XFS_FSB_TO_AGNO(ip->i_mount, irec->br_startblock);
agbno = XFS_FSB_TO_AGBNO(ip->i_mount, irec->br_startblock);
aglen = irec->br_blockcount;
error = xfs_reflink_find_shared(ip->i_mount, agno, agbno,
aglen, &fbno, &flen, true);
if (error)
return error;
*shared = *trimmed = false;
if (fbno == NULLAGBLOCK) {
/* No shared blocks at all. */
return 0;
} else if (fbno == agbno) {
/*
* The start of this extent is shared. Truncate the
* mapping at the end of the shared region so that a
* subsequent iteration starts at the start of the
* unshared region.
*/
irec->br_blockcount = flen;
*shared = true;
if (flen != aglen)
*trimmed = true;
return 0;
} else {
/*
* There's a shared extent midway through this extent.
* Truncate the mapping at the start of the shared
* extent so that a subsequent iteration starts at the
* start of the shared region.
*/
irec->br_blockcount = fbno - agbno;
*trimmed = true;
return 0;
}
}
/*
* Trim the passed in imap to the next shared/unshared extent boundary, and
* if imap->br_startoff points to a shared extent reserve space for it in the
* COW fork. In this case *shared is set to true, else to false.
*
* Note that imap will always contain the block numbers for the existing blocks
* in the data fork, as the upper layers need them for read-modify-write
* operations.
*/
int
xfs_reflink_reserve_cow(
struct xfs_inode *ip,
struct xfs_bmbt_irec *imap,
bool *shared)
{
struct xfs_ifork *ifp = XFS_IFORK_PTR(ip, XFS_COW_FORK);
struct xfs_bmbt_irec got;
int error = 0;
bool eof = false, trimmed;
xfs_extnum_t idx;
/*
* Search the COW fork extent list first. This serves two purposes:
* first this implement the speculative preallocation using cowextisze,
* so that we also unshared block adjacent to shared blocks instead
* of just the shared blocks themselves. Second the lookup in the
* extent list is generally faster than going out to the shared extent
* tree.
*/
if (!xfs_iext_lookup_extent(ip, ifp, imap->br_startoff, &idx, &got))
eof = true;
if (!eof && got.br_startoff <= imap->br_startoff) {
trace_xfs_reflink_cow_found(ip, imap);
xfs_trim_extent(imap, got.br_startoff, got.br_blockcount);
*shared = true;
return 0;
}
/* Trim the mapping to the nearest shared extent boundary. */
error = xfs_reflink_trim_around_shared(ip, imap, shared, &trimmed);
if (error)
return error;
/* Not shared? Just report the (potentially capped) extent. */
if (!*shared)
return 0;
/*
* Fork all the shared blocks from our write offset until the end of
* the extent.
*/
error = xfs_qm_dqattach_locked(ip, 0);
if (error)
return error;
error = xfs_bmapi_reserve_delalloc(ip, XFS_COW_FORK, imap->br_startoff,
imap->br_blockcount, 0, &got, &idx, eof);
if (error == -ENOSPC || error == -EDQUOT)
trace_xfs_reflink_cow_enospc(ip, imap);
if (error)
return error;
trace_xfs_reflink_cow_alloc(ip, &got);
return 0;
}
/* Convert part of an unwritten CoW extent to a real one. */
STATIC int
xfs_reflink_convert_cow_extent(
struct xfs_inode *ip,
struct xfs_bmbt_irec *imap,
xfs_fileoff_t offset_fsb,
xfs_filblks_t count_fsb,
struct xfs_defer_ops *dfops)
{
struct xfs_bmbt_irec irec = *imap;
xfs_fsblock_t first_block = NULLFSBLOCK;
int nimaps = 1;
if (imap->br_state == XFS_EXT_NORM)
return 0;
xfs_trim_extent(&irec, offset_fsb, count_fsb);
trace_xfs_reflink_convert_cow(ip, &irec);
if (irec.br_blockcount == 0)
return 0;
return xfs_bmapi_write(NULL, ip, irec.br_startoff, irec.br_blockcount,
XFS_BMAPI_COWFORK | XFS_BMAPI_CONVERT, &first_block,
0, &irec, &nimaps, dfops);
}
/* Convert all of the unwritten CoW extents in a file's range to real ones. */
int
xfs_reflink_convert_cow(
struct xfs_inode *ip,
xfs_off_t offset,
xfs_off_t count)
{
struct xfs_bmbt_irec got;
struct xfs_defer_ops dfops;
struct xfs_mount *mp = ip->i_mount;
struct xfs_ifork *ifp = XFS_IFORK_PTR(ip, XFS_COW_FORK);
xfs_fileoff_t offset_fsb = XFS_B_TO_FSBT(mp, offset);
xfs_fileoff_t end_fsb = XFS_B_TO_FSB(mp, offset + count);
xfs_extnum_t idx;
bool found;
int error = 0;
xfs_ilock(ip, XFS_ILOCK_EXCL);
/* Convert all the extents to real from unwritten. */
for (found = xfs_iext_lookup_extent(ip, ifp, offset_fsb, &idx, &got);
found && got.br_startoff < end_fsb;
found = xfs_iext_get_extent(ifp, ++idx, &got)) {
error = xfs_reflink_convert_cow_extent(ip, &got, offset_fsb,
end_fsb - offset_fsb, &dfops);
if (error)
break;
}
/* Finish up. */
xfs_iunlock(ip, XFS_ILOCK_EXCL);
return error;
}
/* Allocate all CoW reservations covering a range of blocks in a file. */
static int
__xfs_reflink_allocate_cow(
struct xfs_inode *ip,
xfs_fileoff_t *offset_fsb,
xfs_fileoff_t end_fsb)
{
struct xfs_mount *mp = ip->i_mount;
struct xfs_bmbt_irec imap;
struct xfs_defer_ops dfops;
struct xfs_trans *tp;
xfs_fsblock_t first_block;
int nimaps = 1, error;
bool shared;
xfs_defer_init(&dfops, &first_block);
error = xfs_trans_alloc(mp, &M_RES(mp)->tr_write, 0, 0,
XFS_TRANS_RESERVE, &tp);
if (error)
return error;
xfs_ilock(ip, XFS_ILOCK_EXCL);
/* Read extent from the source file. */
nimaps = 1;
error = xfs_bmapi_read(ip, *offset_fsb, end_fsb - *offset_fsb,
&imap, &nimaps, 0);
if (error)
goto out_unlock;
ASSERT(nimaps == 1);
/* Make sure there's a CoW reservation for it. */
error = xfs_reflink_reserve_cow(ip, &imap, &shared);
if (error)
goto out_trans_cancel;
if (!shared) {
*offset_fsb = imap.br_startoff + imap.br_blockcount;
goto out_trans_cancel;
}
/* Allocate the entire reservation as unwritten blocks. */
xfs_trans_ijoin(tp, ip, 0);
error = xfs_bmapi_write(tp, ip, imap.br_startoff, imap.br_blockcount,
XFS_BMAPI_COWFORK | XFS_BMAPI_PREALLOC, &first_block,
XFS_EXTENTADD_SPACE_RES(mp, XFS_DATA_FORK),
&imap, &nimaps, &dfops);
if (error)
goto out_trans_cancel;
/* Finish up. */
error = xfs_defer_finish(&tp, &dfops, NULL);
if (error)
goto out_trans_cancel;
error = xfs_trans_commit(tp);
*offset_fsb = imap.br_startoff + imap.br_blockcount;
out_unlock:
xfs_iunlock(ip, XFS_ILOCK_EXCL);
return error;
out_trans_cancel:
xfs_defer_cancel(&dfops);
xfs_trans_cancel(tp);
goto out_unlock;
}
/* Allocate all CoW reservations covering a part of a file. */
int
xfs_reflink_allocate_cow_range(
struct xfs_inode *ip,
xfs_off_t offset,
xfs_off_t count)
{
struct xfs_mount *mp = ip->i_mount;
xfs_fileoff_t offset_fsb = XFS_B_TO_FSBT(mp, offset);
xfs_fileoff_t end_fsb = XFS_B_TO_FSB(mp, offset + count);
int error;
ASSERT(xfs_is_reflink_inode(ip));
trace_xfs_reflink_allocate_cow_range(ip, offset, count);
/*
* Make sure that the dquots are there.
*/
error = xfs_qm_dqattach(ip, 0);
if (error)
return error;
while (offset_fsb < end_fsb) {
error = __xfs_reflink_allocate_cow(ip, &offset_fsb, end_fsb);
if (error) {
trace_xfs_reflink_allocate_cow_range_error(ip, error,
_RET_IP_);
return error;
}
}
/* Convert the CoW extents to regular. */
return xfs_reflink_convert_cow(ip, offset, count);
}
/*
* Find the CoW reservation (and whether or not it needs block allocation)
* for a given byte offset of a file.
*/
bool
xfs_reflink_find_cow_mapping(
struct xfs_inode *ip,
xfs_off_t offset,
struct xfs_bmbt_irec *imap,
bool *need_alloc)
{
struct xfs_bmbt_irec irec;
struct xfs_ifork *ifp;
struct xfs_bmbt_rec_host *gotp;
xfs_fileoff_t bno;
xfs_extnum_t idx;
ASSERT(xfs_isilocked(ip, XFS_ILOCK_EXCL | XFS_ILOCK_SHARED));
ASSERT(xfs_is_reflink_inode(ip));
/* Find the extent in the CoW fork. */
ifp = XFS_IFORK_PTR(ip, XFS_COW_FORK);
bno = XFS_B_TO_FSBT(ip->i_mount, offset);
gotp = xfs_iext_bno_to_ext(ifp, bno, &idx);
if (!gotp)
return false;
xfs_bmbt_get_all(gotp, &irec);
if (bno >= irec.br_startoff + irec.br_blockcount ||
bno < irec.br_startoff)
return false;
trace_xfs_reflink_find_cow_mapping(ip, offset, 1, XFS_IO_OVERWRITE,
&irec);
/* If it's still delalloc, we must allocate later. */
*imap = irec;
*need_alloc = !!(isnullstartblock(irec.br_startblock));
return true;
}
/*
* Trim an extent to end at the next CoW reservation past offset_fsb.
*/
int
xfs_reflink_trim_irec_to_next_cow(
struct xfs_inode *ip,
xfs_fileoff_t offset_fsb,
struct xfs_bmbt_irec *imap)
{
struct xfs_bmbt_irec irec;
struct xfs_ifork *ifp;
struct xfs_bmbt_rec_host *gotp;
xfs_extnum_t idx;
if (!xfs_is_reflink_inode(ip))
return 0;
/* Find the extent in the CoW fork. */
ifp = XFS_IFORK_PTR(ip, XFS_COW_FORK);
gotp = xfs_iext_bno_to_ext(ifp, offset_fsb, &idx);
if (!gotp)
return 0;
xfs_bmbt_get_all(gotp, &irec);
/* This is the extent before; try sliding up one. */
if (irec.br_startoff < offset_fsb) {
idx++;
if (idx >= xfs_iext_count(ifp))
return 0;
gotp = xfs_iext_get_ext(ifp, idx);
xfs_bmbt_get_all(gotp, &irec);
}
if (irec.br_startoff >= imap->br_startoff + imap->br_blockcount)
return 0;
imap->br_blockcount = irec.br_startoff - imap->br_startoff;
trace_xfs_reflink_trim_irec(ip, imap);
return 0;
}
/*
* Cancel CoW reservations for some block range of an inode.
*
* If cancel_real is true this function cancels all COW fork extents for the
* inode; if cancel_real is false, real extents are not cleared.
*/
int
xfs_reflink_cancel_cow_blocks(
struct xfs_inode *ip,
struct xfs_trans **tpp,
xfs_fileoff_t offset_fsb,
xfs_fileoff_t end_fsb,
bool cancel_real)
{
struct xfs_ifork *ifp = XFS_IFORK_PTR(ip, XFS_COW_FORK);
struct xfs_bmbt_irec got, prev, del;
xfs_extnum_t idx;
xfs_fsblock_t firstfsb;
struct xfs_defer_ops dfops;
int error = 0, eof = 0;
if (!xfs_is_reflink_inode(ip))
return 0;
xfs_bmap_search_extents(ip, offset_fsb, XFS_COW_FORK, &eof, &idx,
&got, &prev);
if (eof)
return 0;
while (got.br_startoff < end_fsb) {
del = got;
xfs_trim_extent(&del, offset_fsb, end_fsb - offset_fsb);
trace_xfs_reflink_cancel_cow(ip, &del);
if (isnullstartblock(del.br_startblock)) {
error = xfs_bmap_del_extent_delay(ip, XFS_COW_FORK,
&idx, &got, &del);
if (error)
break;
} else if (del.br_state == XFS_EXT_UNWRITTEN || cancel_real) {
xfs_trans_ijoin(*tpp, ip, 0);
xfs_defer_init(&dfops, &firstfsb);
/* Free the CoW orphan record. */
error = xfs_refcount_free_cow_extent(ip->i_mount,
&dfops, del.br_startblock,
del.br_blockcount);
if (error)
break;
xfs_bmap_add_free(ip->i_mount, &dfops,
del.br_startblock, del.br_blockcount,
NULL);
/* Update quota accounting */
xfs_trans_mod_dquot_byino(*tpp, ip, XFS_TRANS_DQ_BCOUNT,
-(long)del.br_blockcount);
/* Roll the transaction */
error = xfs_defer_finish(tpp, &dfops, ip);
if (error) {
xfs_defer_cancel(&dfops);
break;
}
/* Remove the mapping from the CoW fork. */
xfs_bmap_del_extent_cow(ip, &idx, &got, &del);
}
if (++idx >= xfs_iext_count(ifp))
break;
xfs_bmbt_get_all(xfs_iext_get_ext(ifp, idx), &got);
}
/* clear tag if cow fork is emptied */
if (!ifp->if_bytes)
xfs_inode_clear_cowblocks_tag(ip);
return error;
}
/*
* Cancel CoW reservations for some byte range of an inode.
*
* If cancel_real is true this function cancels all COW fork extents for the
* inode; if cancel_real is false, real extents are not cleared.
*/
int
xfs_reflink_cancel_cow_range(
struct xfs_inode *ip,
xfs_off_t offset,
xfs_off_t count,
bool cancel_real)
{
struct xfs_trans *tp;
xfs_fileoff_t offset_fsb;
xfs_fileoff_t end_fsb;
int error;
trace_xfs_reflink_cancel_cow_range(ip, offset, count);
ASSERT(xfs_is_reflink_inode(ip));
offset_fsb = XFS_B_TO_FSBT(ip->i_mount, offset);
if (count == NULLFILEOFF)
end_fsb = NULLFILEOFF;
else
end_fsb = XFS_B_TO_FSB(ip->i_mount, offset + count);
/* Start a rolling transaction to remove the mappings */
error = xfs_trans_alloc(ip->i_mount, &M_RES(ip->i_mount)->tr_write,
0, 0, 0, &tp);
if (error)
goto out;
xfs_ilock(ip, XFS_ILOCK_EXCL);
xfs_trans_ijoin(tp, ip, 0);
/* Scrape out the old CoW reservations */
error = xfs_reflink_cancel_cow_blocks(ip, &tp, offset_fsb, end_fsb,
cancel_real);
if (error)
goto out_cancel;
error = xfs_trans_commit(tp);
xfs_iunlock(ip, XFS_ILOCK_EXCL);
return error;
out_cancel:
xfs_trans_cancel(tp);
xfs_iunlock(ip, XFS_ILOCK_EXCL);
out:
trace_xfs_reflink_cancel_cow_range_error(ip, error, _RET_IP_);
return error;
}
/*
* Remap parts of a file's data fork after a successful CoW.
*/
int
xfs_reflink_end_cow(
struct xfs_inode *ip,
xfs_off_t offset,
xfs_off_t count)
{
struct xfs_ifork *ifp = XFS_IFORK_PTR(ip, XFS_COW_FORK);
struct xfs_bmbt_irec got, prev, del;
struct xfs_trans *tp;
xfs_fileoff_t offset_fsb;
xfs_fileoff_t end_fsb;
xfs_fsblock_t firstfsb;
struct xfs_defer_ops dfops;
int error, eof = 0;
unsigned int resblks;
xfs_filblks_t rlen;
xfs_extnum_t idx;
trace_xfs_reflink_end_cow(ip, offset, count);
/* No COW extents? That's easy! */
if (ifp->if_bytes == 0)
return 0;
offset_fsb = XFS_B_TO_FSBT(ip->i_mount, offset);
end_fsb = XFS_B_TO_FSB(ip->i_mount, offset + count);
/*
* Start a rolling transaction to switch the mappings. We're
* unlikely ever to have to remap 16T worth of single-block
* extents, so just cap the worst case extent count to 2^32-1.
* Stick a warning in just in case, and avoid 64-bit division.
*/
BUILD_BUG_ON(MAX_RW_COUNT > UINT_MAX);
if (end_fsb - offset_fsb > UINT_MAX) {
error = -EFSCORRUPTED;
xfs_force_shutdown(ip->i_mount, SHUTDOWN_CORRUPT_INCORE);
ASSERT(0);
goto out;
}
resblks = XFS_NEXTENTADD_SPACE_RES(ip->i_mount,
(unsigned int)(end_fsb - offset_fsb),
XFS_DATA_FORK);
error = xfs_trans_alloc(ip->i_mount, &M_RES(ip->i_mount)->tr_write,
resblks, 0, 0, &tp);
if (error)
goto out;
xfs_ilock(ip, XFS_ILOCK_EXCL);
xfs_trans_ijoin(tp, ip, 0);
xfs_bmap_search_extents(ip, end_fsb - 1, XFS_COW_FORK, &eof, &idx,
&got, &prev);
/* If there is a hole at end_fsb - 1 go to the previous extent */
if (eof || got.br_startoff > end_fsb) {
/*
* In case of racing, overlapping AIO writes no COW extents
* might be left by the time I/O completes for the loser of
* the race. In that case we are done.
*/
if (idx <= 0)
goto out_cancel;
xfs_bmbt_get_all(xfs_iext_get_ext(ifp, --idx), &got);
}
/* Walk backwards until we're out of the I/O range... */
while (got.br_startoff + got.br_blockcount > offset_fsb) {
del = got;
xfs_trim_extent(&del, offset_fsb, end_fsb - offset_fsb);
/* Extent delete may have bumped idx forward */
if (!del.br_blockcount) {
idx--;
goto next_extent;
}
ASSERT(!isnullstartblock(got.br_startblock));
/*
* Don't remap unwritten extents; these are
* speculatively preallocated CoW extents that have been
* allocated but have not yet been involved in a write.
*/
if (got.br_state == XFS_EXT_UNWRITTEN) {
idx--;
goto next_extent;
}
/* Unmap the old blocks in the data fork. */
xfs_defer_init(&dfops, &firstfsb);
rlen = del.br_blockcount;
error = __xfs_bunmapi(tp, ip, del.br_startoff, &rlen, 0, 1,
&firstfsb, &dfops);
if (error)
goto out_defer;
/* Trim the extent to whatever got unmapped. */
if (rlen) {
xfs_trim_extent(&del, del.br_startoff + rlen,
del.br_blockcount - rlen);
}
trace_xfs_reflink_cow_remap(ip, &del);
/* Free the CoW orphan record. */
error = xfs_refcount_free_cow_extent(tp->t_mountp, &dfops,
del.br_startblock, del.br_blockcount);
if (error)
goto out_defer;
/* Map the new blocks into the data fork. */
error = xfs_bmap_map_extent(tp->t_mountp, &dfops, ip, &del);
if (error)
goto out_defer;
/* Remove the mapping from the CoW fork. */
xfs_bmap_del_extent_cow(ip, &idx, &got, &del);
error = xfs_defer_finish(&tp, &dfops, ip);
if (error)
goto out_defer;
next_extent:
if (idx < 0)
break;
xfs_bmbt_get_all(xfs_iext_get_ext(ifp, idx), &got);
}
error = xfs_trans_commit(tp);
xfs_iunlock(ip, XFS_ILOCK_EXCL);
if (error)
goto out;
return 0;
out_defer:
xfs_defer_cancel(&dfops);
out_cancel:
xfs_trans_cancel(tp);
xfs_iunlock(ip, XFS_ILOCK_EXCL);
out:
trace_xfs_reflink_end_cow_error(ip, error, _RET_IP_);
return error;
}
/*
* Free leftover CoW reservations that didn't get cleaned out.
*/
int
xfs_reflink_recover_cow(
struct xfs_mount *mp)
{
xfs_agnumber_t agno;
int error = 0;
if (!xfs_sb_version_hasreflink(&mp->m_sb))
return 0;
for (agno = 0; agno < mp->m_sb.sb_agcount; agno++) {
error = xfs_refcount_recover_cow_leftovers(mp, agno);
if (error)
break;
}
return error;
}
/*
* Reflinking (Block) Ranges of Two Files Together
*
* First, ensure that the reflink flag is set on both inodes. The flag is an
* optimization to avoid unnecessary refcount btree lookups in the write path.
*
* Now we can iteratively remap the range of extents (and holes) in src to the
* corresponding ranges in dest. Let drange and srange denote the ranges of
* logical blocks in dest and src touched by the reflink operation.
*
* While the length of drange is greater than zero,
* - Read src's bmbt at the start of srange ("imap")
* - If imap doesn't exist, make imap appear to start at the end of srange
* with zero length.
* - If imap starts before srange, advance imap to start at srange.
* - If imap goes beyond srange, truncate imap to end at the end of srange.
* - Punch (imap start - srange start + imap len) blocks from dest at
* offset (drange start).
* - If imap points to a real range of pblks,
* > Increase the refcount of the imap's pblks
* > Map imap's pblks into dest at the offset
* (drange start + imap start - srange start)
* - Advance drange and srange by (imap start - srange start + imap len)
*
* Finally, if the reflink made dest longer, update both the in-core and
* on-disk file sizes.
*
* ASCII Art Demonstration:
*
* Let's say we want to reflink this source file:
*
* ----SSSSSSS-SSSSS----SSSSSS (src file)
* <-------------------->
*
* into this destination file:
*
* --DDDDDDDDDDDDDDDDDDD--DDD (dest file)
* <-------------------->
* '-' means a hole, and 'S' and 'D' are written blocks in the src and dest.
* Observe that the range has different logical offsets in either file.
*
* Consider that the first extent in the source file doesn't line up with our
* reflink range. Unmapping and remapping are separate operations, so we can
* unmap more blocks from the destination file than we remap.
*
* ----SSSSSSS-SSSSS----SSSSSS
* <------->
* --DDDDD---------DDDDD--DDD
* <------->
*
* Now remap the source extent into the destination file:
*
* ----SSSSSSS-SSSSS----SSSSSS
* <------->
* --DDDDD--SSSSSSSDDDDD--DDD
* <------->
*
* Do likewise with the second hole and extent in our range. Holes in the
* unmap range don't affect our operation.
*
* ----SSSSSSS-SSSSS----SSSSSS
* <---->
* --DDDDD--SSSSSSS-SSSSS-DDD
* <---->
*
* Finally, unmap and remap part of the third extent. This will increase the
* size of the destination file.
*
* ----SSSSSSS-SSSSS----SSSSSS
* <----->
* --DDDDD--SSSSSSS-SSSSS----SSS
* <----->
*
* Once we update the destination file's i_size, we're done.
*/
/*
* Ensure the reflink bit is set in both inodes.
*/
STATIC int
xfs_reflink_set_inode_flag(
struct xfs_inode *src,
struct xfs_inode *dest)
{
struct xfs_mount *mp = src->i_mount;
int error;
struct xfs_trans *tp;
if (xfs_is_reflink_inode(src) && xfs_is_reflink_inode(dest))
return 0;
error = xfs_trans_alloc(mp, &M_RES(mp)->tr_ichange, 0, 0, 0, &tp);
if (error)
goto out_error;
/* Lock both files against IO */
if (src->i_ino == dest->i_ino)
xfs_ilock(src, XFS_ILOCK_EXCL);
else
xfs_lock_two_inodes(src, dest, XFS_ILOCK_EXCL);
if (!xfs_is_reflink_inode(src)) {
trace_xfs_reflink_set_inode_flag(src);
xfs_trans_ijoin(tp, src, XFS_ILOCK_EXCL);
src->i_d.di_flags2 |= XFS_DIFLAG2_REFLINK;
xfs_trans_log_inode(tp, src, XFS_ILOG_CORE);
xfs_ifork_init_cow(src);
} else
xfs_iunlock(src, XFS_ILOCK_EXCL);
if (src->i_ino == dest->i_ino)
goto commit_flags;
if (!xfs_is_reflink_inode(dest)) {
trace_xfs_reflink_set_inode_flag(dest);
xfs_trans_ijoin(tp, dest, XFS_ILOCK_EXCL);
dest->i_d.di_flags2 |= XFS_DIFLAG2_REFLINK;
xfs_trans_log_inode(tp, dest, XFS_ILOG_CORE);
xfs_ifork_init_cow(dest);
} else
xfs_iunlock(dest, XFS_ILOCK_EXCL);
commit_flags:
error = xfs_trans_commit(tp);
if (error)
goto out_error;
return error;
out_error:
trace_xfs_reflink_set_inode_flag_error(dest, error, _RET_IP_);
return error;
}
/*
* Update destination inode size & cowextsize hint, if necessary.
*/
STATIC int
xfs_reflink_update_dest(
struct xfs_inode *dest,
xfs_off_t newlen,
xfs_extlen_t cowextsize,
bool is_dedupe)
{
struct xfs_mount *mp = dest->i_mount;
struct xfs_trans *tp;
int error;
if (is_dedupe && newlen <= i_size_read(VFS_I(dest)) && cowextsize == 0)
return 0;
error = xfs_trans_alloc(mp, &M_RES(mp)->tr_ichange, 0, 0, 0, &tp);
if (error)
goto out_error;
xfs_ilock(dest, XFS_ILOCK_EXCL);
xfs_trans_ijoin(tp, dest, XFS_ILOCK_EXCL);
if (newlen > i_size_read(VFS_I(dest))) {
trace_xfs_reflink_update_inode_size(dest, newlen);
i_size_write(VFS_I(dest), newlen);
dest->i_d.di_size = newlen;
}
if (cowextsize) {
dest->i_d.di_cowextsize = cowextsize;
dest->i_d.di_flags2 |= XFS_DIFLAG2_COWEXTSIZE;
}
if (!is_dedupe) {
xfs_trans_ichgtime(tp, dest,
XFS_ICHGTIME_MOD | XFS_ICHGTIME_CHG);
}
xfs_trans_log_inode(tp, dest, XFS_ILOG_CORE);
error = xfs_trans_commit(tp);
if (error)
goto out_error;
return error;
out_error:
trace_xfs_reflink_update_inode_size_error(dest, error, _RET_IP_);
return error;
}
/*
* Do we have enough reserve in this AG to handle a reflink? The refcount
* btree already reserved all the space it needs, but the rmap btree can grow
* infinitely, so we won't allow more reflinks when the AG is down to the
* btree reserves.
*/
static int
xfs_reflink_ag_has_free_space(
struct xfs_mount *mp,
xfs_agnumber_t agno)
{
struct xfs_perag *pag;
int error = 0;
if (!xfs_sb_version_hasrmapbt(&mp->m_sb))
return 0;
pag = xfs_perag_get(mp, agno);
if (xfs_ag_resv_critical(pag, XFS_AG_RESV_AGFL) ||
xfs_ag_resv_critical(pag, XFS_AG_RESV_METADATA))
error = -ENOSPC;
xfs_perag_put(pag);
return error;
}
/*
* Unmap a range of blocks from a file, then map other blocks into the hole.
* The range to unmap is (destoff : destoff + srcioff + irec->br_blockcount).
* The extent irec is mapped into dest at irec->br_startoff.
*/
STATIC int
xfs_reflink_remap_extent(
struct xfs_inode *ip,
struct xfs_bmbt_irec *irec,
xfs_fileoff_t destoff,
xfs_off_t new_isize)
{
struct xfs_mount *mp = ip->i_mount;
struct xfs_trans *tp;
xfs_fsblock_t firstfsb;
unsigned int resblks;
struct xfs_defer_ops dfops;
struct xfs_bmbt_irec uirec;
bool real_extent;
xfs_filblks_t rlen;
xfs_filblks_t unmap_len;
xfs_off_t newlen;
int64_t qres;
int error;
unmap_len = irec->br_startoff + irec->br_blockcount - destoff;
trace_xfs_reflink_punch_range(ip, destoff, unmap_len);
/* Only remap normal extents. */
real_extent = (irec->br_startblock != HOLESTARTBLOCK &&
irec->br_startblock != DELAYSTARTBLOCK &&
!ISUNWRITTEN(irec));
/* No reflinking if we're low on space */
if (real_extent) {
error = xfs_reflink_ag_has_free_space(mp,
XFS_FSB_TO_AGNO(mp, irec->br_startblock));
if (error)
goto out;
}
/* Start a rolling transaction to switch the mappings */
resblks = XFS_EXTENTADD_SPACE_RES(ip->i_mount, XFS_DATA_FORK);
error = xfs_trans_alloc(mp, &M_RES(mp)->tr_write, resblks, 0, 0, &tp);
if (error)
goto out;
xfs_ilock(ip, XFS_ILOCK_EXCL);
xfs_trans_ijoin(tp, ip, 0);
/*
* Reserve quota for this operation. We don't know if the first unmap
* in the dest file will cause a bmap btree split, so we always reserve
* at least enough blocks for that split. If the extent being mapped
* in is written, we need to reserve quota for that too.
*/
qres = XFS_EXTENTADD_SPACE_RES(mp, XFS_DATA_FORK);
if (real_extent)
qres += irec->br_blockcount;
error = xfs_trans_reserve_quota_nblks(tp, ip, qres, 0,
XFS_QMOPT_RES_REGBLKS);
if (error)
goto out_cancel;
trace_xfs_reflink_remap(ip, irec->br_startoff,
irec->br_blockcount, irec->br_startblock);
/* Unmap the old blocks in the data fork. */
rlen = unmap_len;
while (rlen) {
xfs_defer_init(&dfops, &firstfsb);
error = __xfs_bunmapi(tp, ip, destoff, &rlen, 0, 1,
&firstfsb, &dfops);
if (error)
goto out_defer;
/*
* Trim the extent to whatever got unmapped.
* Remember, bunmapi works backwards.
*/
uirec.br_startblock = irec->br_startblock + rlen;
uirec.br_startoff = irec->br_startoff + rlen;
uirec.br_blockcount = unmap_len - rlen;
uirec.br_state = irec->br_state;
unmap_len = rlen;
/* If this isn't a real mapping, we're done. */
if (!real_extent || uirec.br_blockcount == 0)
goto next_extent;
trace_xfs_reflink_remap(ip, uirec.br_startoff,
uirec.br_blockcount, uirec.br_startblock);
/* Update the refcount tree */
error = xfs_refcount_increase_extent(mp, &dfops, &uirec);
if (error)
goto out_defer;
/* Map the new blocks into the data fork. */
error = xfs_bmap_map_extent(mp, &dfops, ip, &uirec);
if (error)
goto out_defer;
/* Update quota accounting. */
xfs_trans_mod_dquot_byino(tp, ip, XFS_TRANS_DQ_BCOUNT,
uirec.br_blockcount);
/* Update dest isize if needed. */
newlen = XFS_FSB_TO_B(mp,
uirec.br_startoff + uirec.br_blockcount);
newlen = min_t(xfs_off_t, newlen, new_isize);
if (newlen > i_size_read(VFS_I(ip))) {
trace_xfs_reflink_update_inode_size(ip, newlen);
i_size_write(VFS_I(ip), newlen);
ip->i_d.di_size = newlen;
xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
}
next_extent:
/* Process all the deferred stuff. */
error = xfs_defer_finish(&tp, &dfops, ip);
if (error)
goto out_defer;
}
error = xfs_trans_commit(tp);
xfs_iunlock(ip, XFS_ILOCK_EXCL);
if (error)
goto out;
return 0;
out_defer:
xfs_defer_cancel(&dfops);
out_cancel:
xfs_trans_cancel(tp);
xfs_iunlock(ip, XFS_ILOCK_EXCL);
out:
trace_xfs_reflink_remap_extent_error(ip, error, _RET_IP_);
return error;
}
/*
* Iteratively remap one file's extents (and holes) to another's.
*/
STATIC int
xfs_reflink_remap_blocks(
struct xfs_inode *src,
xfs_fileoff_t srcoff,
struct xfs_inode *dest,
xfs_fileoff_t destoff,
xfs_filblks_t len,
xfs_off_t new_isize)
{
struct xfs_bmbt_irec imap;
int nimaps;
int error = 0;
xfs_filblks_t range_len;
/* drange = (destoff, destoff + len); srange = (srcoff, srcoff + len) */
while (len) {
trace_xfs_reflink_remap_blocks_loop(src, srcoff, len,
dest, destoff);
/* Read extent from the source file */
nimaps = 1;
xfs_ilock(src, XFS_ILOCK_EXCL);
error = xfs_bmapi_read(src, srcoff, len, &imap, &nimaps, 0);
xfs_iunlock(src, XFS_ILOCK_EXCL);
if (error)
goto err;
ASSERT(nimaps == 1);
trace_xfs_reflink_remap_imap(src, srcoff, len, XFS_IO_OVERWRITE,
&imap);
/* Translate imap into the destination file. */
range_len = imap.br_startoff + imap.br_blockcount - srcoff;
imap.br_startoff += destoff - srcoff;
/* Clear dest from destoff to the end of imap and map it in. */
error = xfs_reflink_remap_extent(dest, &imap, destoff,
new_isize);
if (error)
goto err;
if (fatal_signal_pending(current)) {
error = -EINTR;
goto err;
}
/* Advance drange/srange */
srcoff += range_len;
destoff += range_len;
len -= range_len;
}
return 0;
err:
trace_xfs_reflink_remap_blocks_error(dest, error, _RET_IP_);
return error;
}
/*
* Read a page's worth of file data into the page cache. Return the page
* locked.
*/
static struct page *
xfs_get_page(
struct inode *inode,
xfs_off_t offset)
{
struct address_space *mapping;
struct page *page;
pgoff_t n;
n = offset >> PAGE_SHIFT;
mapping = inode->i_mapping;
page = read_mapping_page(mapping, n, NULL);
if (IS_ERR(page))
return page;
if (!PageUptodate(page)) {
put_page(page);
return ERR_PTR(-EIO);
}
lock_page(page);
return page;
}
/*
* Compare extents of two files to see if they are the same.
*/
static int
xfs_compare_extents(
struct inode *src,
xfs_off_t srcoff,
struct inode *dest,
xfs_off_t destoff,
xfs_off_t len,
bool *is_same)
{
xfs_off_t src_poff;
xfs_off_t dest_poff;
void *src_addr;
void *dest_addr;
struct page *src_page;
struct page *dest_page;
xfs_off_t cmp_len;
bool same;
int error;
error = -EINVAL;
same = true;
while (len) {
src_poff = srcoff & (PAGE_SIZE - 1);
dest_poff = destoff & (PAGE_SIZE - 1);
cmp_len = min(PAGE_SIZE - src_poff,
PAGE_SIZE - dest_poff);
cmp_len = min(cmp_len, len);
ASSERT(cmp_len > 0);
trace_xfs_reflink_compare_extents(XFS_I(src), srcoff, cmp_len,
XFS_I(dest), destoff);
src_page = xfs_get_page(src, srcoff);
if (IS_ERR(src_page)) {
error = PTR_ERR(src_page);
goto out_error;
}
dest_page = xfs_get_page(dest, destoff);
if (IS_ERR(dest_page)) {
error = PTR_ERR(dest_page);
unlock_page(src_page);
put_page(src_page);
goto out_error;
}
src_addr = kmap_atomic(src_page);
dest_addr = kmap_atomic(dest_page);
flush_dcache_page(src_page);
flush_dcache_page(dest_page);
if (memcmp(src_addr + src_poff, dest_addr + dest_poff, cmp_len))
same = false;
kunmap_atomic(dest_addr);
kunmap_atomic(src_addr);
unlock_page(dest_page);
unlock_page(src_page);
put_page(dest_page);
put_page(src_page);
if (!same)
break;
srcoff += cmp_len;
destoff += cmp_len;
len -= cmp_len;
}
*is_same = same;
return 0;
out_error:
trace_xfs_reflink_compare_extents_error(XFS_I(dest), error, _RET_IP_);
return error;
}
/*
* Link a range of blocks from one file to another.
*/
int
xfs_reflink_remap_range(
struct file *file_in,
loff_t pos_in,
struct file *file_out,
loff_t pos_out,
u64 len,
bool is_dedupe)
{
struct inode *inode_in = file_inode(file_in);
struct xfs_inode *src = XFS_I(inode_in);
struct inode *inode_out = file_inode(file_out);
struct xfs_inode *dest = XFS_I(inode_out);
struct xfs_mount *mp = src->i_mount;
loff_t bs = inode_out->i_sb->s_blocksize;
bool same_inode = (inode_in == inode_out);
xfs_fileoff_t sfsbno, dfsbno;
xfs_filblks_t fsblen;
xfs_extlen_t cowextsize;
loff_t isize;
ssize_t ret;
loff_t blen;
if (!xfs_sb_version_hasreflink(&mp->m_sb))
return -EOPNOTSUPP;
if (XFS_FORCED_SHUTDOWN(mp))
return -EIO;
/* Lock both files against IO */
if (same_inode) {
xfs_ilock(src, XFS_IOLOCK_EXCL);
xfs_ilock(src, XFS_MMAPLOCK_EXCL);
} else {
xfs_lock_two_inodes(src, dest, XFS_IOLOCK_EXCL);
xfs_lock_two_inodes(src, dest, XFS_MMAPLOCK_EXCL);
}
/* Don't touch certain kinds of inodes */
ret = -EPERM;
if (IS_IMMUTABLE(inode_out))
goto out_unlock;
ret = -ETXTBSY;
if (IS_SWAPFILE(inode_in) || IS_SWAPFILE(inode_out))
goto out_unlock;
/* Don't reflink dirs, pipes, sockets... */
ret = -EISDIR;
if (S_ISDIR(inode_in->i_mode) || S_ISDIR(inode_out->i_mode))
goto out_unlock;
ret = -EINVAL;
if (S_ISFIFO(inode_in->i_mode) || S_ISFIFO(inode_out->i_mode))
goto out_unlock;
if (!S_ISREG(inode_in->i_mode) || !S_ISREG(inode_out->i_mode))
goto out_unlock;
/* Don't reflink realtime inodes */
if (XFS_IS_REALTIME_INODE(src) || XFS_IS_REALTIME_INODE(dest))
goto out_unlock;
/* Don't share DAX file data for now. */
if (IS_DAX(inode_in) || IS_DAX(inode_out))
goto out_unlock;
/* Are we going all the way to the end? */
isize = i_size_read(inode_in);
if (isize == 0) {
ret = 0;
goto out_unlock;
}
/* Zero length dedupe exits immediately; reflink goes to EOF. */
if (len == 0) {
if (is_dedupe) {
ret = 0;
goto out_unlock;
}
len = isize - pos_in;
}
/* Ensure offsets don't wrap and the input is inside i_size */
if (pos_in + len < pos_in || pos_out + len < pos_out ||
pos_in + len > isize)
goto out_unlock;
/* Don't allow dedupe past EOF in the dest file */
if (is_dedupe) {
loff_t disize;
disize = i_size_read(inode_out);
if (pos_out >= disize || pos_out + len > disize)
goto out_unlock;
}
/* If we're linking to EOF, continue to the block boundary. */
if (pos_in + len == isize)
blen = ALIGN(isize, bs) - pos_in;
else
blen = len;
/* Only reflink if we're aligned to block boundaries */
if (!IS_ALIGNED(pos_in, bs) || !IS_ALIGNED(pos_in + blen, bs) ||
!IS_ALIGNED(pos_out, bs) || !IS_ALIGNED(pos_out + blen, bs))
goto out_unlock;
/* Don't allow overlapped reflink within the same file */
if (same_inode) {
if (pos_out + blen > pos_in && pos_out < pos_in + blen)
goto out_unlock;
}
/* Wait for the completion of any pending IOs on both files */
inode_dio_wait(inode_in);
if (!same_inode)
inode_dio_wait(inode_out);
ret = filemap_write_and_wait_range(inode_in->i_mapping,
pos_in, pos_in + len - 1);
if (ret)
goto out_unlock;
ret = filemap_write_and_wait_range(inode_out->i_mapping,
pos_out, pos_out + len - 1);
if (ret)
goto out_unlock;
trace_xfs_reflink_remap_range(src, pos_in, len, dest, pos_out);
/*
* Check that the extents are the same.
*/
if (is_dedupe) {
bool is_same = false;
ret = xfs_compare_extents(inode_in, pos_in, inode_out, pos_out,
len, &is_same);
if (ret)
goto out_unlock;
if (!is_same) {
ret = -EBADE;
goto out_unlock;
}
}
ret = xfs_reflink_set_inode_flag(src, dest);
if (ret)
goto out_unlock;
/*
* Invalidate the page cache so that we can clear any CoW mappings
* in the destination file.
*/
truncate_inode_pages_range(&inode_out->i_data, pos_out,
PAGE_ALIGN(pos_out + len) - 1);
dfsbno = XFS_B_TO_FSBT(mp, pos_out);
sfsbno = XFS_B_TO_FSBT(mp, pos_in);
fsblen = XFS_B_TO_FSB(mp, len);
ret = xfs_reflink_remap_blocks(src, sfsbno, dest, dfsbno, fsblen,
pos_out + len);
if (ret)
goto out_unlock;
/*
* Carry the cowextsize hint from src to dest if we're sharing the
* entire source file to the entire destination file, the source file
* has a cowextsize hint, and the destination file does not.
*/
cowextsize = 0;
if (pos_in == 0 && len == i_size_read(inode_in) &&
(src->i_d.di_flags2 & XFS_DIFLAG2_COWEXTSIZE) &&
pos_out == 0 && len >= i_size_read(inode_out) &&
!(dest->i_d.di_flags2 & XFS_DIFLAG2_COWEXTSIZE))
cowextsize = src->i_d.di_cowextsize;
ret = xfs_reflink_update_dest(dest, pos_out + len, cowextsize,
is_dedupe);
out_unlock:
xfs_iunlock(src, XFS_MMAPLOCK_EXCL);
xfs_iunlock(src, XFS_IOLOCK_EXCL);
if (src->i_ino != dest->i_ino) {
xfs_iunlock(dest, XFS_MMAPLOCK_EXCL);
xfs_iunlock(dest, XFS_IOLOCK_EXCL);
}
if (ret)
trace_xfs_reflink_remap_range_error(dest, ret, _RET_IP_);
return ret;
}
/*
* The user wants to preemptively CoW all shared blocks in this file,
* which enables us to turn off the reflink flag. Iterate all
* extents which are not prealloc/delalloc to see which ranges are
* mentioned in the refcount tree, then read those blocks into the
* pagecache, dirty them, fsync them back out, and then we can update
* the inode flag. What happens if we run out of memory? :)
*/
STATIC int
xfs_reflink_dirty_extents(
struct xfs_inode *ip,
xfs_fileoff_t fbno,
xfs_filblks_t end,
xfs_off_t isize)
{
struct xfs_mount *mp = ip->i_mount;
xfs_agnumber_t agno;
xfs_agblock_t agbno;
xfs_extlen_t aglen;
xfs_agblock_t rbno;
xfs_extlen_t rlen;
xfs_off_t fpos;
xfs_off_t flen;
struct xfs_bmbt_irec map[2];
int nmaps;
int error = 0;
while (end - fbno > 0) {
nmaps = 1;
/*
* Look for extents in the file. Skip holes, delalloc, or
* unwritten extents; they can't be reflinked.
*/
error = xfs_bmapi_read(ip, fbno, end - fbno, map, &nmaps, 0);
if (error)
goto out;
if (nmaps == 0)
break;
if (map[0].br_startblock == HOLESTARTBLOCK ||
map[0].br_startblock == DELAYSTARTBLOCK ||
ISUNWRITTEN(&map[0]))
goto next;
map[1] = map[0];
while (map[1].br_blockcount) {
agno = XFS_FSB_TO_AGNO(mp, map[1].br_startblock);
agbno = XFS_FSB_TO_AGBNO(mp, map[1].br_startblock);
aglen = map[1].br_blockcount;
error = xfs_reflink_find_shared(mp, agno, agbno, aglen,
&rbno, &rlen, true);
if (error)
goto out;
if (rbno == NULLAGBLOCK)
break;
/* Dirty the pages */
xfs_iunlock(ip, XFS_ILOCK_EXCL);
fpos = XFS_FSB_TO_B(mp, map[1].br_startoff +
(rbno - agbno));
flen = XFS_FSB_TO_B(mp, rlen);
if (fpos + flen > isize)
flen = isize - fpos;
error = iomap_file_dirty(VFS_I(ip), fpos, flen,
&xfs_iomap_ops);
xfs_ilock(ip, XFS_ILOCK_EXCL);
if (error)
goto out;
map[1].br_blockcount -= (rbno - agbno + rlen);
map[1].br_startoff += (rbno - agbno + rlen);
map[1].br_startblock += (rbno - agbno + rlen);
}
next:
fbno = map[0].br_startoff + map[0].br_blockcount;
}
out:
return error;
}
/* Clear the inode reflink flag if there are no shared extents. */
int
xfs_reflink_clear_inode_flag(
struct xfs_inode *ip,
struct xfs_trans **tpp)
{
struct xfs_mount *mp = ip->i_mount;
xfs_fileoff_t fbno;
xfs_filblks_t end;
xfs_agnumber_t agno;
xfs_agblock_t agbno;
xfs_extlen_t aglen;
xfs_agblock_t rbno;
xfs_extlen_t rlen;
struct xfs_bmbt_irec map;
int nmaps;
int error = 0;
ASSERT(xfs_is_reflink_inode(ip));
fbno = 0;
end = XFS_B_TO_FSB(mp, i_size_read(VFS_I(ip)));
while (end - fbno > 0) {
nmaps = 1;
/*
* Look for extents in the file. Skip holes, delalloc, or
* unwritten extents; they can't be reflinked.
*/
error = xfs_bmapi_read(ip, fbno, end - fbno, &map, &nmaps, 0);
if (error)
return error;
if (nmaps == 0)
break;
if (map.br_startblock == HOLESTARTBLOCK ||
map.br_startblock == DELAYSTARTBLOCK ||
ISUNWRITTEN(&map))
goto next;
agno = XFS_FSB_TO_AGNO(mp, map.br_startblock);
agbno = XFS_FSB_TO_AGBNO(mp, map.br_startblock);
aglen = map.br_blockcount;
error = xfs_reflink_find_shared(mp, agno, agbno, aglen,
&rbno, &rlen, false);
if (error)
return error;
/* Is there still a shared block here? */
if (rbno != NULLAGBLOCK)
return 0;
next:
fbno = map.br_startoff + map.br_blockcount;
}
/*
* We didn't find any shared blocks so turn off the reflink flag.
* First, get rid of any leftover CoW mappings.
*/
error = xfs_reflink_cancel_cow_blocks(ip, tpp, 0, NULLFILEOFF, true);
if (error)
return error;
/* Clear the inode flag. */
trace_xfs_reflink_unset_inode_flag(ip);
ip->i_d.di_flags2 &= ~XFS_DIFLAG2_REFLINK;
xfs_inode_clear_cowblocks_tag(ip);
xfs_trans_ijoin(*tpp, ip, 0);
xfs_trans_log_inode(*tpp, ip, XFS_ILOG_CORE);
return error;
}
/*
* Clear the inode reflink flag if there are no shared extents and the size
* hasn't changed.
*/
STATIC int
xfs_reflink_try_clear_inode_flag(
struct xfs_inode *ip)
{
struct xfs_mount *mp = ip->i_mount;
struct xfs_trans *tp;
int error = 0;
/* Start a rolling transaction to remove the mappings */
error = xfs_trans_alloc(mp, &M_RES(mp)->tr_write, 0, 0, 0, &tp);
if (error)
return error;
xfs_ilock(ip, XFS_ILOCK_EXCL);
xfs_trans_ijoin(tp, ip, 0);
error = xfs_reflink_clear_inode_flag(ip, &tp);
if (error)
goto cancel;
error = xfs_trans_commit(tp);
if (error)
goto out;
xfs_iunlock(ip, XFS_ILOCK_EXCL);
return 0;
cancel:
xfs_trans_cancel(tp);
out:
xfs_iunlock(ip, XFS_ILOCK_EXCL);
return error;
}
/*
* Pre-COW all shared blocks within a given byte range of a file and turn off
* the reflink flag if we unshare all of the file's blocks.
*/
int
xfs_reflink_unshare(
struct xfs_inode *ip,
xfs_off_t offset,
xfs_off_t len)
{
struct xfs_mount *mp = ip->i_mount;
xfs_fileoff_t fbno;
xfs_filblks_t end;
xfs_off_t isize;
int error;
if (!xfs_is_reflink_inode(ip))
return 0;
trace_xfs_reflink_unshare(ip, offset, len);
inode_dio_wait(VFS_I(ip));
/* Try to CoW the selected ranges */
xfs_ilock(ip, XFS_ILOCK_EXCL);
fbno = XFS_B_TO_FSBT(mp, offset);
isize = i_size_read(VFS_I(ip));
end = XFS_B_TO_FSB(mp, offset + len);
error = xfs_reflink_dirty_extents(ip, fbno, end, isize);
if (error)
goto out_unlock;
xfs_iunlock(ip, XFS_ILOCK_EXCL);
/* Wait for the IO to finish */
error = filemap_write_and_wait(VFS_I(ip)->i_mapping);
if (error)
goto out;
/* Turn off the reflink flag if possible. */
error = xfs_reflink_try_clear_inode_flag(ip);
if (error)
goto out;
return 0;
out_unlock:
xfs_iunlock(ip, XFS_ILOCK_EXCL);
out:
trace_xfs_reflink_unshare_error(ip, error, _RET_IP_);
return error;
}