android_kernel_msm-6.1_noth.../lib
David Howells 7ff5062079 iov_iter: Add ITER_XARRAY
Add an iterator, ITER_XARRAY, that walks through a set of pages attached to
an xarray, starting at a given page and offset and walking for the
specified amount of bytes.  The iterator supports transparent huge pages.

The iterate_xarray() macro calls the helper function with rcu_access()
helped.  I think that this is only a problem for iov_iter_for_each_range()
- and that returns an error for ITER_XARRAY (also, this function does not
appear to be called).

The caller must guarantee that the pages are all present and they must be
locked using PG_locked, PG_writeback or PG_fscache to prevent them from
going away or being migrated whilst they're being accessed.

This is useful for copying data from socket buffers to inodes in network
filesystems and for transferring data between those inodes and the cache
using direct I/O.

Whilst it is true that ITER_BVEC could be used instead, that would require
a bio_vec array to be allocated to refer to all the pages - which should be
redundant if inode->i_pages also points to all these pages.

Note that older versions of this patch implemented an ITER_MAPPING instead,
which was almost the same.

Changes:
v7:
 - Rename iter_xarray_copy_pages() to iter_xarray_populate_pages()[1].

Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-and-tested-by: Jeff Layton <jlayton@kernel.org>
Tested-by: Dave Wysochanski <dwysocha@redhat.com>
Tested-By: Marc Dionne <marc.dionne@auristor.com>
cc: Alexander Viro <viro@zeniv.linux.org.uk>
cc: Matthew Wilcox (Oracle) <willy@infradead.org>
cc: Christoph Hellwig <hch@lst.de>
cc: linux-mm@kvack.org
cc: linux-cachefs@redhat.com
cc: linux-afs@lists.infradead.org
cc: linux-nfs@vger.kernel.org
cc: linux-cifs@vger.kernel.org
cc: ceph-devel@vger.kernel.org
cc: v9fs-developer@lists.sourceforge.net
cc: linux-fsdevel@vger.kernel.org
Link: https://lore.kernel.org/r/3577430.1579705075@warthog.procyon.org.uk/ # rfc
Link: https://lore.kernel.org/r/158861205740.340223.16592990225607814022.stgit@warthog.procyon.org.uk/ # rfc
Link: https://lore.kernel.org/r/159465785214.1376674.6062549291411362531.stgit@warthog.procyon.org.uk/
Link: https://lore.kernel.org/r/160588477334.3465195.3608963255682568730.stgit@warthog.procyon.org.uk/ # rfc
Link: https://lore.kernel.org/r/161118129703.1232039.17141248432017826976.stgit@warthog.procyon.org.uk/ # rfc
Link: https://lore.kernel.org/r/161161026313.2537118.14676007075365418649.stgit@warthog.procyon.org.uk/ # v2
Link: https://lore.kernel.org/r/161340386671.1303470.10752208972482479840.stgit@warthog.procyon.org.uk/ # v3
Link: https://lore.kernel.org/r/161539527815.286939.14607323792547049341.stgit@warthog.procyon.org.uk/ # v4
Link: https://lore.kernel.org/r/161653786033.2770958.14154191921867463240.stgit@warthog.procyon.org.uk/ # v5
Link: https://lore.kernel.org/r/161789064740.6155.11932541175173658065.stgit@warthog.procyon.org.uk/ # v6
Link: https://lore.kernel.org/r/27c369a8f42bb8a617672b2dc0126a5c6df5a050.camel@kernel.org [1]
2021-04-23 09:15:32 +01:00
..
842 kbuild: trace functions in subdirectories of lib/ 2020-08-10 01:32:59 +09:00
crypto crypto: lib/chacha20poly1305 - define empty module exit function 2021-01-22 14:58:03 +11:00
dim Revert "lib: Revert use of fallthrough pseudo-keyword in lib/" 2020-11-18 14:15:17 -06:00
fonts Fonts: font_ter16x32: Update font with new upstream Terminus release 2021-01-07 21:06:25 +01:00
kunit kunit: add kunit.filter_glob cmdline option to filter suites 2021-02-08 16:09:27 -07:00
livepatch Kbuild updates for v5.9 2020-08-09 14:10:26 -07:00
lz4 lib/lz4: explicitly support in-place decompression 2020-12-15 22:46:16 -08:00
lzo lib/lzo/lzo1x_compress.c: make lzogeneric1x_1_compress() static 2020-12-15 22:46:19 -08:00
math kernel.h: split out mathematical helpers 2020-12-15 22:46:15 -08:00
mpi lib/mpi: Remove unused scalar_copied 2020-10-30 17:34:45 +11:00
pldmfw Add pldmfw library for PLDM firmware update 2020-07-28 17:07:06 -07:00
raid6 lib/raid6: Let $(UNROLL) rules work with macOS userland 2021-01-04 10:38:11 +09:00
reed_solomon kbuild: trace functions in subdirectories of lib/ 2020-08-10 01:32:59 +09:00
vdso vdso/treewide: Add vdso_data pointer argument to __arch_get_hw_counter() 2020-08-06 10:57:30 +02:00
xz Revert "lib: Revert use of fallthrough pseudo-keyword in lib/" 2020-11-18 14:15:17 -06:00
zlib_deflate kbuild: trace functions in subdirectories of lib/ 2020-08-10 01:32:59 +09:00
zlib_dfltcc zlib: move EXPORT_SYMBOL() and MODULE_LICENSE() out of dfltcc_syms.c 2020-12-29 15:36:49 -08:00
zlib_inflate lib: Fix fall-through warnings for Clang 2020-11-19 07:23:47 -06:00
zstd lib: Fix fall-through warnings for Clang 2020-11-19 07:23:47 -06:00
.gitignore .gitignore: add SPDX License Identifier 2020-03-25 11:50:48 +01:00
argv_split.c
ashldi3.c
ashrdi3.c
asn1_decoder.c Revert "lib: Revert use of fallthrough pseudo-keyword in lib/" 2020-11-18 14:15:17 -06:00
assoc_array.c Revert "lib: Revert use of fallthrough pseudo-keyword in lib/" 2020-11-18 14:15:17 -06:00
atomic64.c
atomic64_test.c
audit.c
bcd.c
bch.c lib/bch: Allow easy bit swapping 2020-05-24 20:48:11 +02:00
bitfield_kunit.c lib: kunit: Fix compilation test when using TEST_BIT_FIELD_COMPILE 2020-10-16 13:25:14 -06:00
bitmap.c lib: bitmap: delete duplicated words 2020-10-16 11:11:19 -07:00
bitrev.c
bootconfig.c Revert "lib: Revert use of fallthrough pseudo-keyword in lib/" 2020-11-18 14:15:17 -06:00
bsearch.c lib/bsearch: Provide __always_inline variant 2020-06-11 15:14:53 +02:00
btree.c
bucket_locks.c
bug.c module: mark module_mutex static 2021-02-08 12:24:26 +01:00
build_OID_registry
buildid.c bpf: Add size arg to build_id_parse function 2021-01-14 19:29:58 -08:00
bust_spinlocks.c
check_signature.c
checksum.c unify generic instances of csum_partial_copy_nocheck() 2020-08-20 15:45:14 -04:00
clz_ctz.c
clz_tab.c
cmdline.c lib/cmdline: remove an unneeded local variable in next_arg() 2021-02-26 09:41:04 -08:00
cmdline_kunit.c lib/cmdline: Allow get_options() to take 0 to validate the input 2021-02-15 11:43:31 +01:00
cmpdi2.c
compat_audit.c
cpu_rmap.c
cpumask.c Revert "lib: Restrict cpumask_local_spread to houskeeping CPUs" 2021-02-05 23:28:29 +01:00
crc-ccitt.c
crc-itu-t.c
crc-t10dif.c crc-t10dif: clean up some more things 2020-06-18 17:26:43 +10:00
crc4.c
crc7.c lib/crc7: fix a kernel-doc markup 2021-01-21 14:06:00 -07:00
crc8.c
crc16.c
crc32.c lib/crc32.c: fix trivial typo in preprocessor condition 2020-10-16 11:11:20 -07:00
crc32defs.h
crc32test.c lib/crc32test: remove extra local_irq_disable/enable 2020-11-02 12:14:19 -08:00
crc64.c lib/: replace HTTP links with HTTPS ones 2020-08-12 10:58:00 -07:00
ctype.c
debug_info.c
debug_locks.c lockdep: Prepare for noinstr sections 2020-05-19 15:47:21 +02:00
debugobjects.c debugobjects: Free per CPU pool after CPU unplug 2020-10-01 16:13:54 +02:00
dec_and_lock.c
decompress.c lib: Add zstd support to decompress 2020-07-31 11:49:08 +02:00
decompress_bunzip2.c lib: decompress_bunzip2: delete duplicated words 2020-10-16 11:11:19 -07:00
decompress_inflate.c lib/zlib: add s390 hardware support for kernel zlib_inflate 2020-01-31 10:30:40 -08:00
decompress_unlz4.c
decompress_unlzma.c lib/: replace HTTP links with HTTPS ones 2020-08-12 10:58:00 -07:00
decompress_unlzo.c
decompress_unxz.c
decompress_unzstd.c lib: decompress_unzstd: Limit output size 2020-09-03 10:13:09 +02:00
devmem_is_allowed.c lib: Add a generic version of devmem_is_allowed() 2020-12-11 12:28:08 -08:00
devres.c driver core: platform: Document return type of more functions 2020-09-10 18:30:01 +02:00
digsig.c crypto: sha - split sha.h into sha1.h and sha2.h 2020-11-20 14:45:33 +11:00
dump_stack.c stop_machine: Add function and caller debug info 2020-11-10 18:38:57 +01:00
dynamic_debug.c dyndbg: fix use before null check 2020-12-09 20:10:12 +01:00
dynamic_queue_limits.c lib: dynamic_queue_limits: delete duplicated words + fix typo 2020-10-16 11:11:20 -07:00
earlycpio.c lib: earlycpio: delete duplicated words 2020-10-16 11:11:20 -07:00
errname.c kernel.h: split out mathematical helpers 2020-12-15 22:46:15 -08:00
error-inject.c fault-injection: handle EI_ETYPE_TRUE 2020-12-15 22:46:19 -08:00
errseq.c kernel.h: split out mathematical helpers 2020-12-15 22:46:15 -08:00
extable.c sparc32: switch to generic extables 2021-01-03 20:05:18 -05:00
fault-inject-usercopy.c lib, include/linux: add usercopy failure capability 2020-10-16 11:11:22 -07:00
fault-inject.c fault_inject: Don't rely on "return value" from WRITE_ONCE() 2020-04-15 21:36:41 +01:00
fdt.c
fdt_addresses.c libfdt: include fdt_addresses.c 2020-01-08 16:59:19 +00:00
fdt_empty_tree.c
fdt_ro.c
fdt_rw.c
fdt_strerror.c
fdt_sw.c
fdt_wip.c
find_bit.c kernel.h: split out mathematical helpers 2020-12-15 22:46:15 -08:00
find_bit_benchmark.c
flex_proportions.c lib/flex_proportions.c: cleanup __fprop_inc_percpu_max 2020-06-04 19:06:25 -07:00
gen_crc32table.c
gen_crc64table.c
genalloc.c lib/genalloc.c: change return type to unsigned long for bitmap_set_ll 2021-02-26 09:41:04 -08:00
generic-radix-tree.c
glob.c Revert "lib: Revert use of fallthrough pseudo-keyword in lib/" 2020-11-18 14:15:17 -06:00
globtest.c
hexdump.c kernel.h: split out min()/max() et al. helpers 2020-10-16 11:11:19 -07:00
hweight.c
idr.c XArray updates for 5.9 2020-10-20 14:39:37 -07:00
inflate.c
interval_tree.c
interval_tree_test.c
iomap.c iomap: constify ioreadX() iomem argument (as in generic implementation) 2020-08-14 19:56:57 -07:00
iomap_copy.c
iommu-helper.c
iov_iter.c iov_iter: Add ITER_XARRAY 2021-04-23 09:15:32 +01:00
irq_poll.c
irq_regs.c
is_single_threaded.c
kasprintf.c
Kconfig lib: stackdepot: add support to configure STACK_HASH_SIZE 2021-02-26 09:41:04 -08:00
Kconfig.debug mm: add Kernel Electric-Fence infrastructure 2021-02-26 09:41:02 -08:00
Kconfig.kasan kasan: fix KASAN_STACK dependency for HW_TAGS 2021-03-13 11:27:31 -08:00
Kconfig.kcsan kcsan: Test support for compound instrumentation 2020-08-24 15:09:58 -07:00
Kconfig.kfence kfence: add test suite 2021-02-26 09:41:02 -08:00
Kconfig.kgdb kgdb: Honour the kprobe blocklist when setting breakpoints 2020-09-28 12:14:08 +01:00
Kconfig.ubsan ubsan: remove overflow checks 2021-02-26 09:41:05 -08:00
kfifo.c
klist.c
kobject.c kobject: Drop unneeded conditional in __kobject_del() 2020-09-07 11:24:17 +02:00
kobject_uevent.c
kstrtox.c lib: Fix fall-through warnings for Clang 2020-11-19 07:23:47 -06:00
kstrtox.h
libcrc32c.c lib: libcrc32c: delete duplicated words 2020-10-16 11:11:19 -07:00
linear_ranges.c lib/linear_ranges: fix repeated words & one typo 2020-12-28 12:24:47 +00:00
list-test.c Fix linked-list KUnit test when run multiple times 2020-03-25 16:38:39 -06:00
list_debug.c
list_sort.c
llist.c
locking-selftest-hardirq.h
locking-selftest-mutex.h
locking-selftest-rlock-hardirq.h
locking-selftest-rlock-softirq.h
locking-selftest-rlock.h
locking-selftest-rsem.h
locking-selftest-rtmutex.h
locking-selftest-softirq.h
locking-selftest-spin-hardirq.h
locking-selftest-spin-softirq.h
locking-selftest-spin.h
locking-selftest-wlock-hardirq.h
locking-selftest-wlock-softirq.h
locking-selftest-wlock.h
locking-selftest-wsem.h
locking-selftest.c locking/selftests: Add local_lock inversion tests 2021-01-14 11:20:18 +01:00
lockref.c
logic_pio.c PCI: Fix pci_register_io_range() memory leak 2021-02-17 17:31:06 -06:00
lru_cache.c
lshrdi3.c
Makefile kasan: rename CONFIG_TEST_KASAN_MODULE 2021-02-24 13:38:31 -08:00
memcat_p.c
memory-notifier-error-inject.c
memregion.c lib/memregion.c: include memregion.h 2020-09-26 10:33:57 -07:00
memweight.c
muldi3.c
net_utils.c
netdev-notifier-error-inject.c
nlattr.c fallthrough fixes for Clang for 5.11-rc1 2020-12-16 00:24:16 -08:00
nmi_backtrace.c lib: Add backtrace_idle parameter to force backtrace of idle CPUs 2020-08-24 14:24:25 -07:00
nodemask.c
notifier-error-inject.c
notifier-error-inject.h
objagg.c lib: objagg: Replace zero-length arrays with flexible-array member 2020-02-16 18:33:00 -08:00
of-reconfig-notifier-error-inject.c
oid_registry.c
once.c
packing.c lib: packing: add documentation for pbuflen argument 2020-06-28 20:45:27 -07:00
parman.c lib/parman: Delete newline 2021-02-15 15:31:52 -08:00
parser.c parser: Fix kernel-doc markups 2021-02-03 19:10:42 +01:00
pci_iomap.c
percpu-refcount.c percpu_ref: Dump mem_dump_obj() info upon reference-count underflow 2021-01-22 15:24:23 -08:00
percpu_counter.c lib/percpu_counter.c: use helper macro abs() 2020-10-16 11:11:20 -07:00
percpu_test.c
plist.c
pm-notifier-error-inject.c
radix-tree.c XArray updates for 5.9 2020-10-20 14:39:37 -07:00
random32.c random32: add a selftest for the prandom32 code 2020-10-24 20:21:57 +02:00
ratelimit.c
rbtree.c lib/: replace HTTP links with HTTPS ones 2020-08-12 10:58:00 -07:00
rbtree_test.c
refcount.c locking/refcount: Consolidate implementations of refcount_t 2019-11-25 09:15:32 +01:00
rhashtable.c rhashtable: Restore RCU marking on rhash_lock_head 2020-07-28 17:09:49 -07:00
sbitmap.c sbitmap: simplify wrap check 2020-12-07 17:12:49 -07:00
scatterlist.c lib/scatterlist: use consistent sg_copy_buffer() return type 2020-10-29 08:55:45 -06:00
seq_buf.c seq_buf: Export seq_buf_printf 2020-06-15 18:22:43 -07:00
sg_pool.c
sg_split.c
sha1.c crypto: sha - split sha.h into sha1.h and sha2.h 2020-11-20 14:45:33 +11:00
show_mem.c
siphash.c Revert "lib: Revert use of fallthrough pseudo-keyword in lib/" 2020-11-18 14:15:17 -06:00
smp_processor_id.c sched: Make migrate_disable/enable() independent of RT 2020-11-24 11:25:44 +01:00
sort.c lib/sort: Move swap, cmp and cmp_r function types for wider use 2019-11-14 13:15:11 -05:00
stackdepot.c lib: stackdepot: fix ignoring return value warning 2021-02-26 09:41:04 -08:00
stmp_device.c
string.c lib/string: remove unnecessary #undefs 2020-12-15 22:46:16 -08:00
string_helpers.c lib: string_helpers: provide kfree_strarray() 2020-09-30 10:50:30 +02:00
strncpy_from_user.c lib/strncpy_from_user.c: Mask out bytes after NUL terminator. 2020-11-19 11:56:16 -08:00
strnlen_user.c uaccess: Selectively open read or write user access 2020-05-01 12:35:21 +10:00
syscall.c lib/syscall: fix syscall registers retrieval on 32-bit platforms 2020-12-03 09:52:44 -08:00
test-kstrtox.c
test-string_helpers.c lib/test-string_helpers.c: Add string_upper() and string_lower() tests 2020-07-15 12:45:06 +03:00
test_bitmap.c lib: use KSTM_MODULE_GLOBALS macro in kselftest drivers 2021-02-15 11:01:42 +01:00
test_bitops.c lib/test_bitops: do the full test during module init 2020-08-12 10:57:59 -07:00
test_bits.c lib/test_bits.c: add tests of GENMASK 2020-08-12 10:58:00 -07:00
test_blackhole_dev.c
test_bpf.c test_bpf: Remove EXPECTED_FAIL flag from bpf_fill_maxinsns11 2021-01-20 14:13:48 -08:00
test_debug_virtual.c
test_firmware.c lib: cleanup kstrto*() usage 2020-12-15 22:46:16 -08:00
test_fpu.c selftests/fpu: Fix debugfs_simple_attr.cocci warning 2021-01-18 11:03:26 +01:00
test_free_pages.c lib/test_free_pages.c: add basic progress indicators 2020-12-15 22:46:16 -08:00
test_hash.c
test_hexdump.c
test_hmm.c lib/test_hmm.c: fix an error code in dmirror_allocate_chunk() 2020-10-16 11:11:20 -07:00
test_hmm_uapi.h mm/hmm: add tests for hmm_pfn_to_map_order() 2020-07-10 16:24:28 -03:00
test_ida.c
test_kasan.c kasan, mm: fail krealloc on freed objects 2021-02-26 09:41:03 -08:00
test_kasan_module.c kasan: clean up comments in tests 2021-02-24 13:38:30 -08:00
test_kmod.c lib: cleanup kstrto*() usage 2020-12-15 22:46:16 -08:00
test_linear_ranges.c lib/test_linear_ranges: add a test for the 'linear_ranges' 2020-05-08 18:18:12 +01:00
test_list_sort.c
test_lockup.c lib/test_lockup.c: minimum fix to get it compiled on PREEMPT_RT 2020-12-15 22:46:16 -08:00
test_memcat_p.c
test_meminit.c lib/test_meminit.c: add bulk alloc/free tests 2019-12-04 19:44:13 -08:00
test_min_heap.c lib: Introduce generic min-heap 2020-03-06 11:56:59 +01:00
test_module.c
test_objagg.c test_objagg: Fix potential memory leak in error handling 2020-06-15 13:32:11 -07:00
test_overflow.c
test_parman.c
test_printf.c printk changes for 5.12 2021-02-22 11:04:36 -08:00
test_rhashtable.c rhashtable: fix indentation of a continue statement 2020-09-20 14:10:06 -07:00
test_siphash.c
test_sort.c
test_stackinit.c lib: test_stackinit.c: XFAIL switch variable init tests 2020-04-07 10:43:43 -07:00
test_static_key_base.c
test_static_keys.c
test_string.c
test_strscpy.c
test_sysctl.c lib: test_sysctl: delete duplicated words 2020-10-16 11:11:20 -07:00
test_ubsan.c ubsan: remove overflow checks 2021-02-26 09:41:05 -08:00
test_user_copy.c
test_uuid.c
test_vmalloc.c lib/test_vmalloc.c: Add test cases for kvfree_rcu() 2020-06-29 11:59:26 -07:00
test_xarray.c XArray updates for 5.9 2020-10-20 14:39:37 -07:00
textsearch.c
timerqueue.c rbtree, timerqueue: Use rb_add_cached() 2021-02-17 14:08:01 +01:00
ts_bm.c lib/: replace HTTP links with HTTPS ones 2020-08-12 10:58:00 -07:00
ts_fsm.c Revert "lib: Revert use of fallthrough pseudo-keyword in lib/" 2020-11-18 14:15:17 -06:00
ts_kmp.c lib/ts_kmp.c: replace zero-length array with flexible-array member 2020-04-07 10:43:43 -07:00
ubsan.c ubsan: remove overflow checks 2021-02-26 09:41:05 -08:00
ubsan.h ubsan: implement __ubsan_handle_alignment_assumption 2021-02-05 11:03:47 -08:00
ucmpdi2.c
ucs2_string.c
usercopy.c lib, uaccess: add failure injection to usercopy functions 2020-10-16 11:11:22 -07:00
uuid.c uuid: Provide a GUID generator for raw buffer 2020-03-23 17:01:47 +01:00
vsprintf.c lib/vsprintf: no_hash_pointers prints all addresses as unhashed 2021-02-15 11:08:32 +01:00
win_minmax.c
xarray.c XArray updates for 5.9 2020-10-20 14:39:37 -07:00
xxhash.c lib/: replace HTTP links with HTTPS ones 2020-08-12 10:58:00 -07:00