Commit Graph

14640 Commits

Author SHA1 Message Date
Denys Vlasenko
ad5394d591 factor: add code to test isqrt() correctness
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2017-04-10 13:53:57 +02:00
Denys Vlasenko
dd3a395053 factor: 25% faster sieving
function                                             old     new   delta
factorize                                            287     260     -27

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2017-04-10 12:10:46 +02:00
Denys Vlasenko
4908c79a01 factor: better comments, slightl more clever conversion even->odd
function                                             old     new   delta
isqrt_odd                                            114     111      -3

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2017-04-10 11:47:48 +02:00
Denys Vlasenko
f428f1dc6c factor: fix HALF_FMT usage
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2017-04-10 10:13:14 +02:00
Denys Vlasenko
12dc4fbf18 factor: fix comments
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2017-04-10 00:41:11 +02:00
Denys Vlasenko
bef1713217 factor: a bit more simple isqrt
function                                             old     new   delta
isqrt_odd                                             87      80      -7

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2017-04-10 00:28:26 +02:00
Denys Vlasenko
c6476dca54 factor: simpler isqrt
function                                             old     new   delta
isqrt_odd                                            102      87     -15

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2017-04-10 00:24:16 +02:00
Denys Vlasenko
c804d4ec5c factor: factor2 variable is unused now, drop it
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2017-04-09 23:19:47 +02:00
Denys Vlasenko
7e5f2f3b51 factor: expand comments
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2017-04-09 23:12:38 +02:00
Denys Vlasenko
1d232fd440 factor: 30% faster code (estimate max possible factor just once)
function                                             old     new   delta
factorize                                              -     161    +161
isqrt_odd                                              -     102    +102
factor_main                                          281     110    -171
------------------------------------------------------------------------------
(add/remove: 2/0 grow/shrink: 0/1 up/down: 263/-171)           Total: 92 bytes

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2017-04-09 22:54:57 +02:00
Denys Vlasenko
c1b5b2a190 nl: fix copyright message
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2017-04-09 21:19:29 +02:00
Denys Vlasenko
ee7f75d94f factor: new applet
thus far only able to factor up to ULLONG_MAX

function                                             old     new   delta
factor_main                                            -     378    +378
packed_usage                                       31427   31502     +75
applet_names                                        2590    2597      +7
applet_main                                         1500    1504      +4
------------------------------------------------------------------------------
(add/remove: 2/0 grow/shrink: 3/0 up/down: 464/0)             Total: 464 bytes

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2017-04-09 21:18:43 +02:00
Denys Vlasenko
87ae0fe095 nproc: new applet
function                                             old     new   delta
nproc_main                                             -      98     +98
applet_names                                        2584    2590      +6
applet_main                                         1496    1500      +4
applet_install_loc                                   187     188      +1

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2017-04-07 21:47:53 +02:00
Denys Vlasenko
0f7f1ae094 shred: smaller code
function                                             old     new   delta
shred_main                                           361     356      -5

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2017-04-07 21:10:00 +02:00
Denys Vlasenko
2f59bf39e2 shred: new applet
function                                             old     new   delta
shred_main                                             -     361    +361
packed_usage                                       31427   31467     +40
applet_names                                        2578    2584      +6
applet_main                                         1492    1496      +4
run_applet_and_exit                                  679     682      +3
------------------------------------------------------------------------------
(add/remove: 2/0 grow/shrink: 4/0 up/down: 414/0)             Total: 414 bytes

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2017-04-07 20:45:08 +02:00
Denys Vlasenko
42776708f2 init: dont send "Sent SIGTERM to all" msg to syslog: we just TERMed it!
While at it, explain FEATURE_INIT_SYSLOG

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2017-04-07 19:13:09 +02:00
Denys Vlasenko
7121bb8023 ipaddress: tweak help text more: mention "brd +" syntax
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2017-04-07 18:22:41 +02:00
Denys Vlasenko
4eaa0f7729 ipaddress: tweak help text
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2017-04-07 18:14:46 +02:00
Denys Vlasenko
eb76abb4f7 iproute: add "a" command as a synonym to "add"
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2017-04-07 17:33:26 +02:00
Denys Vlasenko
826bdcd51c libiproute: FACT_FUNCization
function                                             old     new   delta
get_addr_1                                           258     287     +29
next_arg                                               -      22     +22
print_neigh                                          885     902     +17
do_iplink                                           1269    1276      +7
get_unsigned                                          54      55      +1
get_u32                                               54      55      +1
get_u16                                               62      63      +1
rt_addr_n2a                                           53      52      -1
ipaddr_modify                                       1229    1226      -3
get_addr32                                            58      54      -4
invarg_1_to_2                                         18      12      -6
inet_addr_match                                      109     103      -6
duparg2                                               18      12      -6
duparg                                                18      12      -6
print_addrinfo                                      1231    1223      -8
ipneigh_list_or_flush                                724     714     -10
incomplete_command                                    10       -     -10
iproute_get                                          847     835     -12
ipaddr_list_or_flush                                1265    1253     -12
get_prefix                                           356     344     -12
do_add_or_delete                                    1162    1150     -12
get_addr                                              73      58     -15
iproute_list_or_flush                               1210    1191     -19
parse_args                                          1434    1412     -22
print_rule                                           634     610     -24
iprule_modify                                        864     816     -48
print_route                                         1621    1565     -56
iproute_modify                                      1221    1164     -57
------------------------------------------------------------------------------
(add/remove: 1/1 grow/shrink: 6/20 up/down: 78/-349)         Total: -271 bytes

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2017-04-07 17:15:40 +02:00
Denys Vlasenko
d5342a1ad1 iproute: support advmss option
function                                             old     new   delta
iproute_modify                                      1164    1221     +57
str_is_lock                                            -      22     +22
packed_usage                                       31372   31382     +10
do_iproute                                           157     132     -25
------------------------------------------------------------------------------
(add/remove: 1/0 grow/shrink: 2/1 up/down: 89/-25)             Total: 64 bytes

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2017-04-07 17:00:53 +02:00
Denys Vlasenko
1140bf39ab iproute: update help text, add commented-out code for unsupported options
function                                             old     new   delta
packed_usage                                       31327   31372     +45
do_iproute                                           132     157     +25
iproute_modify                                      1162    1164      +2
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 3/0 up/down: 72/0)               Total: 72 bytes

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2017-04-06 17:54:38 +02:00
Denys Vlasenko
2d4823b65b iplink: implement "set promisc on|off". Closes 4682
function                                             old     new   delta
do_iplink                                           1232    1269     +37
packed_usage                                       31337   31327     -10

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2017-04-06 16:06:04 +02:00
Denys Vlasenko
a7386bb35b ip link: tidying up
Misplaced comment. --help was wrong: dynamic on|off is not supported.

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2017-04-06 15:55:29 +02:00
Denys Vlasenko
4f0b540d08 modprobe: do not descend into /etc/modprobe.d/DIR/. Closes 8686
Also expanded comments in recursive_action.c

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2017-04-06 15:23:26 +02:00
Denys Vlasenko
0d6e3ad663 modprobe-small: fix "modprobe non-existing-module" exitcode (should be 1)
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2017-04-06 13:45:00 +02:00
Ben Hutchings
803c85a207 modprobe: read modules.builtin
This allows explicit probing to succeed when the requested module
is actually built-in, and corrects the error message for removal.

Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2017-04-06 11:54:04 +02:00
Denys Vlasenko
9c192e7f94 examples: make udhcpc script handle /32 netmasks
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2017-04-06 00:53:43 +02:00
Jody Bruchon
19578b4edf Add help text for 'uniq -i'
Signed-off-by: Jody Bruchon <jody@jodybruchon.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2017-04-05 18:51:27 +02:00
Denys Vlasenko
e7ac7abf06 nl: use CONFIG_NL, not CONFIG_UNIQ
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2017-04-05 18:31:19 +02:00
Denys Vlasenko
d88f94a5df nl: new applet; also implement cat -nb (similar functionality to nl)
function                                             old     new   delta
nl_main                                                -     201    +201
print_numbered_lines                                   -     115    +115
cat_main                                              36     149    +113
static.nl_longopts                                     -     106    +106
packed_usage                                       31081   31182    +101
applet_main                                         1488    1492      +4
applet_names                                        2575    2578      +3
applet_suid                                           93      94      +1
applet_install_loc                                   186     187      +1
------------------------------------------------------------------------------
(add/remove: 4/0 grow/shrink: 6/0 up/down: 645/0)             Total: 645 bytes

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2017-04-05 18:17:17 +02:00
Denys Vlasenko
5d561ef634 tls: do not compile in TLS_RSA_WITH_NULL_SHA256 code if unreachable
function                                             old     new   delta
tls_handshake                                       1595    1588      -7
xwrite_encrypted                                     244     209     -35

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2017-04-04 01:41:15 +02:00
Denys Vlasenko
229d3c467d tls: avoid using int16 in pstm code
function                                             old     new   delta
pstm_div                                            1472    1522     +50
psRsaEncryptPub                                      403     413     +10
pstm_2expt                                            91      96      +5
pstm_clear                                            68      72      +4
pstm_init                                             39      42      +3
pstm_unsigned_bin_size                                36      37      +1
pstm_montgomery_reduce                               398     399      +1
pstm_init_size                                        45      46      +1
pstm_zero                                             39      38      -1
pstm_set                                              35      34      -1
pstm_read_unsigned_bin                               112     109      -3
pstm_mulmod                                          123     120      -3
pstm_mod                                             116     113      -3
pstm_cmp                                              57      54      -3
pstm_sub                                             107     102      -5
pstm_to_unsigned_bin                                 157     151      -6
pstm_clamp                                            63      57      -6
pstm_add                                             116     108      -8
pstm_grow                                             81      72      -9
pstm_count_bits                                       57      48      -9
pstm_init_copy                                        84      72     -12
pstm_cmp_mag                                          93      78     -15
pstm_sqr_comba                                       567     551     -16
pstm_montgomery_calc_normalization                   158     140     -18
pstm_copy                                            115      92     -23
pstm_lshd                                            133     109     -24
pstm_mul_comba                                       525     500     -25
pstm_mul_d                                           251     224     -27
s_pstm_sub                                           256     228     -28
s_pstm_add                                           370     337     -33
pstm_div_2d                                          444     409     -35
pstm_mul_2                                           195     156     -39
pstm_rshd                                            154     104     -50
pstm_mul_2d                                          247     186     -61
pstm_exptmod                                        1524    1463     -61
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 8/27 up/down: 75/-524)         Total: -449 bytes

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2017-04-03 21:53:29 +02:00
Denys Vlasenko
636c3b627c tls: merge sha1 and sha256 hmac functions
function                                             old     new   delta
hmac_begin                                             -     196    +196
hmac_sha256                                           61      68      +7
hmac                                                 250      87    -163
hmac_sha256_begin                                    190       -    -190
------------------------------------------------------------------------------
(add/remove: 1/1 grow/shrink: 1/1 up/down: 203/-353)         Total: -150 bytes

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2017-04-03 17:43:44 +02:00
Denys Vlasenko
6e99f1cb45 tls: replace aes encryption/decryption by much smaller one
The replacement code is ~6 times slower,
but drastically decreases size of tls_aes.o:

text	data	bss	dec	hex	filename
8050	0	0	8050	1f72	tls_aes_OLD.o
2461	0	0	2461	99d	tls_aes.o

function                                             old     new   delta
sbox                                                   -     256    +256
rsbox                                                  -     256    +256
KeyExpansion                                           -     197    +197
Subword                                                -      66     +66
AddRoundKey                                            -      61     +61
static.Rcon                                            -      10     +10
rcon                                                  40       -     -40
setup_mix                                             80       -     -80
setup_mix2                                           123       -    -123
aes_cbc_decrypt                                     1377     971    -406
aes_cbc_encrypt                                     1375     644    -731
psAesInit                                            848       -    -848
Te4                                                 1024       -   -1024
TE0                                                 1024       -   -1024
TD0                                                 1024       -   -1024
Td4                                                 1040       -   -1040
------------------------------------------------------------------------------
(add/remove: 6/8 grow/shrink: 0/2 up/down: 846/-6340)       Total: -5494 bytes

This code is based on public domain "tiny-AES128-C" code.

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2017-04-01 20:11:59 +02:00
Jody Bruchon
8808f7fc2e uniq: add -i option to ignore case
Signed-off-by: Jody Bruchon <jody@jodybruchon.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2017-03-30 18:15:54 +02:00
Kang-Che Sung
257734855c Update depmod & modprobe upstream help text in comments
No code changes.

Signed-off-by: Kang-Che Sung <explorer09@gmail.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2017-03-28 18:26:21 +02:00
Denys Vlasenko
ab03061615 udhcp6: move misplaced comment
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2017-03-27 22:49:12 +02:00
Denys Vlasenko
ed898ed2dd udhcp6: fix releasing
Patch is based on work by tiggerswelt.net. They say:
"
We wanted udhcpc6 to release its IPv6-Addresses on
quit (-R-commandline-option) which turned out to generate once again
kind of garbage on the network-link.
We tracked this down to two issues:

 - udhcpc6 uses a variable called "srv6_buf" to send packets to
   the dhcp6-server, but this variable is never initialized correctly
   and contained kind of a garbage-address

 - The address of the dhcp6-server is usually a link-local-address,
   that requires an interface-index when using connect() on an AF_INET6-
   socket

We added an
additional parameter for ifindex to d6_send_kernel_packet() and made
d6_recv_raw_packet() to capture the address of the dhcp6-server and
forward it to its callee.
"

Three last patches together:

function                                             old     new   delta
d6_read_interface                                      -     454    +454
d6_recv_raw_packet                                     -     283    +283
option_to_env                                        249     504    +255
.rodata                                           165226  165371    +145
send_d6_discover                                     195     237     +42
send_d6_select                                       118     159     +41
send_d6_renew                                        173     186     +13
send_d6_release                                      162     173     +11
opt_req                                                -      10     +10
d6_send_kernel_packet                                304     312      +8
opt_fqdn_req                                           -       6      +6
d6_mcast_from_client_config_ifindex                   48      51      +3
d6_find_option                                        63      61      -2
udhcpc6_main                                        2416    2411      -5
static.d6_recv_raw_packet                            266       -    -266
------------------------------------------------------------------------------
(add/remove: 5/1 grow/shrink: 8/2 up/down: 1271/-273)         Total: 998 bytes

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2017-03-27 22:44:22 +02:00
Denys Vlasenko
64d58aa806 udhcp6: fix problems found running against dnsmasq
Patch is based on work by tiggerswelt.net. They say:
"
But when we tried to use dnsmasq on server-side, udhcpc6 was unable to
forward the acquired address to its setup-script although the
IPv6-Address had been assigned by the server as we could see via
tcpdump. We traced this issue down to a problem on how udhcpc6 parses
DHCPv6-Options: When moving to next option, a pointer-address is
increased and a length buffer is decreased by the length of the option.
The problem is that it is done in this order:

  option += 4 + option[3];
  len_m4 -= 4 + option[3];

But this has to be switched as the length is decreased by the length of
the *next* option, not the current one. This affected both - internal
checks if a required option is present and the function to expose
options to the environment of the setup-script.
There was also a bug parsing D6_OPT_STATUS_CODE Options, that made
dnsmasq not work as udhcpc6 thought it is receiving a non-positive
status-code (because it did not parse the status-code as required in RFC
3315).
In addition we introduced basic support for RFC 3646 (OPTION_DNS_SERVERS
and OPTION_DOMAIN_LIST) and RFC 4704 (OPTION_CLIENT_FQDN).
"

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2017-03-27 22:41:59 +02:00
Denys Vlasenko
e09f5e3045 udhcp6: read_interface should save link-local ipv6 address
Patch is based on work by tiggerswelt.net. They say:
"Using this patch it was no problem to acquire an IPv6-Address via DHCPv6
using ISC DHCPD6 on server-side."

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2017-03-27 22:41:59 +02:00
Yousong Zhou
8f3bf4f0d3 vi: avoid touching a new file with ZZ when no editing has been done
This is the behaviour observed with standard vim and busybox vi of at
least 1.22.1.  It was changed with commit "32afd3a vi: some
simplifications" which happened before 1.23.0.

Mistyping filename on command line happens fairly often and it's better
we restore the old behaviour to avoid a few unnecessary flash writes and
sometimes efforts of debugging bugs caused by those unneeded stray
files.

Signed-off-by: Yousong Zhou <yszhou4tech@gmail.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2017-03-24 21:13:10 +01:00
Andrei Gherzan
e3b65ab43d switch_root: don't bail out when console doesn't exist
Busybox is very often used in initramfs at the end of which usually
there is a switch_root to the actual rootfs. There are many cases where
the console kernel argument is either just a placeholder (for example
RaspberryPi uses serial0 and serial1) or configured as null to avoid any
console messages - usually you would see such of a setup in production
environments.

Currently busybox bails out if can't open the console argument. If this
happenes in initramfs and if the console=null for example, you get in a
blind kernel panic. Avoid this by only warning instead of dying.

function                                             old     new   delta
switch_root_main                                     371     368      -3

Signed-off-by: Andrei Gherzan <andrei@gherzan.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2017-03-24 16:39:08 +01:00
Denys Vlasenko
876c121ccb whitespace fix
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2017-03-24 15:00:12 +01:00
Denys Vlasenko
f4a670a911 paste: delimiter list use should restart for each new output line
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2017-03-23 17:58:32 +01:00
Denys Vlasenko
f1db95abfb typo fix
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2017-03-23 17:41:59 +01:00
Maxime Coste
d2383f57cd paste: new applet
function                                             old     new   delta
paste_main                                             -     493    +493
packed_usage                                       31019   31070     +51
applet_names                                        2569    2575      +6
applet_main                                         1484    1488      +4
------------------------------------------------------------------------------
(add/remove: 2/0 grow/shrink: 3/0 up/down: 554/0)             Total: 554 bytes

Signed-off-by: Maxime Coste <mawww@kakoune.org>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2017-03-23 17:35:52 +01:00
Rostislav Skudnov
dba0dc1999 dd: call fsync() only once before exiting if conv=fsync is specified
Signed-off-by: Rostislav Skudnov <rostislav@tuxera.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2017-03-16 20:54:35 +01:00
Denys Vlasenko
a98db793cf Revert "umount: make -d always active, add -D to suppress it"
This reverts commit 86a03bee1d.

Since now our "mount -oloop" creates AUTOCLEARed loopdevs, we no longer
need our umount to destroy loopdevs to match the usual util-linux behaviour.

Now this revert fixes another, opposite bug: "explicit" mount /dev/loopN
and then umount must not drop loopdevs!

User complaint is as follows:

It seems LOOP_CLR_FD called on a loop-*partition* removes the mapping of
the whole *device* - which results in the following:

root@LEDE:/# loop=$(losetup -f)
root@LEDE:/# echo ${loop}
/dev/loop2
root@LEDE:/# losetup ${loop} /IMAGE
root@LEDE:/# ls -l ${loop}*
brw-------  1 root root     7,   2 Mar  6 20:09 /dev/loop2
root@LEDE:/# partprobe ${loop}
root@LEDE:/# ls -l ${loop}*
brw-------  1 root  root    7,   2 Mar  6 20:09 /dev/loop2
brw-------  1 root  root  259,   8 Mar  6 21:59 /dev/loop2p1
brw-------  1 root  root  259,   9 Mar  6 21:59 /dev/loop2p2
brw-------  1 root  root  259,  10 Mar  6 21:59 /dev/loop2p3
brw-------  1 root  root  259,  11 Mar  6 21:59 /dev/loop2p4
brw-------  1 root  root  259,  12 Mar  6 21:59 /dev/loop2p5
brw-------  1 root  root  259,  13 Mar  6 21:59 /dev/loop2p6
brw-------  1 root  root  259,  14 Mar  6 21:59 /dev/loop2p7
brw-------  1 root  root  259,  15 Mar  6 21:59 /dev/loop2p8
root@LEDE:/# mount ${loop}p8 /MOUNT       # mount loop partition
root@LEDE:/# losetup -a | grep $loop      # loop dev mapping still there
/dev/loop2: 0 /mnt/IMAGE
root@LEDE:/# strace umount /MOUNT 2> /log # unmount loop partition
root@LEDE:/# losetup -a | grep ${loop}    # loop device mapping is gone
root@LEDE:/# grep -i loop /log
open("/dev/loop2p7", O_RDONLY|O_LARGEFILE) = 3
ioctl(3, LOOP_CLR_FD)                   = 0
root@LEDE:/#

The strace was done to figure out, if maybe umount wrongly ioctl()'s the
parent device instead of the partition - it doesn't.

I already wasn't a fan of umount implicitly removing the mapping in the
first place (as I usually setup and release loop devices with `losetup`
and scripts needed to call umount differently in order to work and
outside busybox).

However taking above (kernel-)behaviour into account - umount calling
ioctl(LOOP_CLR_FD) unconditionally potentially causes some nasty side
effects

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2017-03-16 17:51:06 +01:00
Denys Vlasenko
ab518eea9c mount: create loop devices with LO_FLAGS_AUTOCLEAR flag
The "autolooped" mount (mount [-oloop] IMAGE /DIR/DIR)
always creates AUTOCLEARed loopdevs, so that umounting
drops them (and this does not require any code in the
umount userspace).
This happens since circa linux-2.6.25:
	commit 96c5865559cee0f9cbc5173f3c949f6ce3525581
	Date:    Wed Feb 6 01:36:27 2008 -0800
	Subject: Allow auto-destruction of loop devices
IOW: in this case, umount does not have to use -d
to drop the loopdev.

The explicit loop mount (mount /dev/loopN /DIR/DIR)
does not do this. In this case, umount without -d
should not drop loopdev.
Unfortunately, bbox umount currently always implies -d,
this probably needs fixing.

function                                             old     new   delta
set_loop                                             537     597     +60
singlemount                                         1101    1138     +37
losetup_main                                         419     432     +13
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 3/0 up/down: 110/0)             Total: 110 bytes

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2017-03-16 16:55:47 +01:00