Commit Graph

61 Commits

Author SHA1 Message Date
Xiaoming Ni
cb8d2ea8c9 loop: fix a race when a free loop device is snatched
When /dev/loop-control exists and *device is empty,
the mount may fail if a concurrent mount is running.

function                                             old     new   delta
set_loop                                             809     807      -2

Signed-off-by: Xiaoming Ni <nixiaoming@huawei.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2022-11-15 14:54:05 +01:00
Denys Vlasenko
15733cb48e mount: if we race with other loop mount, we forget to close loop dev
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2020-12-17 23:38:06 +01:00
Denys Vlasenko
4bc59a4cf7 mount: fix a race when a free loop device is snatched under us by another mount.
function                                             old     new   delta
set_loop                                             850     809     -41

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2020-12-17 15:05:14 +01:00
Steffen Trumtrar
6561e07460 mount: support the sizelimit and offset option for loop devices
Starting with linux kernel v5.4 squashfs has a more strict parameter
checking implemented. Unlike util-linux mount, busybox never supported
the sizelimit option but simply forwards it to the kernel.
Since v5.4 mounting will fail with

    squashfs: Unknown parameter 'sizelimit'

Support the sizelimit parameter by setting it in the LOOP_SET_STATUS64
structure before handing it to the kernel.

While at it also add support for the offset option, which currently will
always be set to 0.

function                                             old     new   delta
cut_out_ull_opt                                        -     167    +167
singlemount                                         1230    1266     +36
set_loop                                             834     862     +28
losetup_main                                         479     483      +4
------------------------------------------------------------------------------
(add/remove: 1/0 grow/shrink: 3/0 up/down: 235/0)             Total: 235 bytes

Signed-off-by: Steffen Trumtrar <s.trumtrar@pengutronix.de>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2020-10-01 00:31:11 +02:00
Denys Vlasenko
3b69ba799f mount,losetup: use /dev/loop-control is it exists
function                                             old     new   delta
get_free_loop                                          -      58     +58
set_loop                                             597     649     +52
losetup_main                                         482     476      -6
------------------------------------------------------------------------------
(add/remove: 1/0 grow/shrink: 1/1 up/down: 110/-6)            Total: 104 bytes

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2019-06-09 23:20:49 +02:00
Denys Vlasenko
335766602b testsuite/mount.tests: fix false positive
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2018-06-28 14:10:00 +02:00
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
Kevin Wallace
782ee2aa0e libbb/loop: don't try to re-use existing loop device
loopinfo.lo_file_name is not enough to uniquely identify a file on a system with
multiple mount namespaces.  We could conceivably change this to dedup on
(lo_rdevice, lo_inode), but, as the comment above the deleted code notes, this
whole approach of reusing devices is racy anyway, so it seems better to stop
doing it entirely.

Signed-off-by: Kevin Wallace <k@igneous.io>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2015-02-07 19:13:57 +01:00
Denys Vlasenko
fa6ab56353 libbb: if opening /dev/loopN returns ENXIO, don't try N++.
function                                             old     new   delta
set_loop                                             639     635      -4

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2014-01-21 13:44:21 +01:00
Denys Vlasenko
60cb48ca50 whitespace cleanup. no code changes
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2013-01-14 15:57:44 +01:00
Denys Vlasenko
13e709c53f losetup: implement -r option. Closes 4033.
function                                             old     new   delta
packed_usage                                       28595   28633     +38
losetup_main                                         285     290      +5
singlemount                                          906     908      +2
set_loop                                             674     672      -2

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2011-09-12 08:30:16 +02:00
Denys Vlasenko
0ef64bdb40 *: make GNU licensing statement forms more regular
This change retains "or later" state! No licensing _changes_ here,
only form is adjusted (article, space between "GPL" and "v2" and so on).

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2010-08-16 20:14:46 +02:00
Denys Vlasenko
92510141e2 losetup: support /dev/loop10 and higher. closes bug 1627
function                                             old     new   delta
query_loop                                            91      95      +4
losetup_main                                         288     285      -3

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2010-05-19 00:39:17 +02:00
Denys Vlasenko
b9dd5ab6d9 loop: correct minor device number limit
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2010-04-14 13:52:41 -07:00
Lauri Kasanen
375a8ef5ea mount: add an optional capability to create new /dev/loopN as needed
Signed-off-by: Lauri Kasanen <curaga@operamail.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2010-04-14 12:31:26 -07:00
Denys Vlasenko
98f1dc12f1 libbb/loop: comment out u32 hack
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2010-03-18 14:38:21 +01:00
Denys Vlasenko
41d8134511 libbb/loop.c: move #include to its user, improve comment
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2010-03-08 23:10:23 +01:00
Denys Vlasenko
8cb40361c0 libbb/loop.c: use common fix_u32.h trick
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2010-03-06 20:50:29 +01:00
Denys Vlasenko
44fbfa78ca libbb/loop.c: style and readability fixes, no code changes
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2010-03-05 13:20:28 +01:00
Denys Vlasenko
90a9904e9e remove some GNUisms. by Dan Fandrich (dan AT coneharvesters.com)
function                                             old     new   delta
logdirs_reopen                                      1310    1308      -2
read_line_input                                     4757    4753      -4
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 0/2 up/down: 0/-6)               Total: -6 bytes

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2009-09-06 02:36:23 +02:00
Denys Vlasenko
9b1b62adc4 Patches to enable FreeBSD build
platform.h: fix wrong check for endianness, fix lchown
aliasing to chown on uclibc.

Code seems to not be affected in my testing.

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2009-07-05 03:34:12 +02:00
Denis Vlasenko
defc1ea340 *: introduce and use FAST_FUNC: regparm on i386, otherwise no-on
text    data     bss     dec     hex filename
 808035     611    6868  815514   c719a busybox_old
 804472     611    6868  811951   c63af busybox_unstripped
2008-06-27 02:52:20 +00:00
Denis Vlasenko
0e2c9fb4e0 mount: print errno on NFS error (again) 2007-08-03 14:16:24 +00:00
Denis Vlasenko
c34d35557b loop device code: readability improvement 2007-04-19 00:09:34 +00:00
Denis Vlasenko
4ebaf10742 strdup -> xstrdup
sed: de-obfuscate piece of code
2007-01-19 21:33:19 +00:00
Denis Vlasenko
7039a66b58 correct largefile support, add comments about it. 2006-10-08 17:54:47 +00:00
Denis Vlasenko
1385899416 attempt to regularize atoi mess. 2006-10-08 12:49:22 +00:00
Denis Vlasenko
9213a9e0f2 whitespace cleanup 2006-09-17 16:28:10 +00:00
Rob Landley
d921b2ecc0 Remove bb_ prefixes from xfuncs.c (and a few other places), consolidate
things like xasprintf() into xfuncs.c, remove xprint_file_by_name() (it only
had one user), clean up lots of #includes...  General cleanup pass.  What I've
been doing for the last couple days.

And it conflicts!  I've removed httpd.c from this checkin due to somebody else
touching that file.  It builds for me.  I have to catch a bus.  (Now you know
why I'm looking forward to Mercurial.)
2006-08-03 15:41:12 +00:00
Rob Landley
534374755d Cleaup read() and write() variants, plus a couple of new functions like
xlseek and fdlength() for the new mkswap.
2006-07-16 08:14:35 +00:00
"Robert P. J. Day"
5d8843e451 Replace current verbose GPL stuff in libbb/*.c with one-line GPL boilerplate. 2006-07-10 11:41:19 +00:00
Rob Landley
a892bf8284 Whitespace. (Vim's auto-indent is kind of annoying at times, like "daytime"
and "nighttime"...)
2006-06-25 15:37:28 +00:00
Rob Landley
934da82913 Fix a possible race condition if two processes try to claim the same loop
device at the same time.  We should only CLR_FD if the set status fails,
not if the SET_FD fails.
2006-06-25 15:29:12 +00:00
Rob Landley
aae8b3405e Whitespace cleanup and minor tweak (return -ERRNO instead of ERRNO so
EPERM doesn't register as a successful read-only mount.
2006-03-18 02:38:10 +00:00
Eric Andersen
76b24270d4 with 2.4 kernel headers, lo_file_name is char, but with 2.6
headers we get a u8 for lo_file_name, so always cast to (char *)
when treating it as such.
2006-01-30 17:30:22 +00:00
Tim Riker
c1ef7bdd8d just whitespace 2006-01-25 00:08:53 +00:00
Rob Landley
b70ccd9509 Close bug 644: loop incrementing twice, skipping ever other device. 2006-01-22 23:17:18 +00:00
Rob Landley
9085467970 Trying to losetup a device as a regular user shouldn't result in an endless
loop, and the error messages should display correctly now.
2005-12-21 16:53:57 +00:00
Rob Landley
1d589b2e2d Fix losetup so that it A) actually works again, B) has much better error
messages, C) can show the current association (if any) when called
with only one argument.  Update the documentation a lot too.

Remind me to add a test suite for this thing.  I think I've figured out
how to handle root-only testsuites...
2005-11-29 23:47:10 +00:00
Bernhard Reutner-Fischer
7547a6e2f6 - don't update copyright years. He might release it, but apparently will have
to update the year himself.
2005-10-15 20:56:31 +00:00
Bernhard Reutner-Fischer
94c3331d47 - an empty middle term in ?: violates ISO C
- use shorter boilerplate and use C89 style comments
2005-10-15 14:13:09 +00:00
Rob Landley
ff567f7943 The check for EROFS was wrong. For example, if you try to mount a filesystem
appended to an executable that's being run (yes, I'm doing this) you get
EPERM, but mounting readonly fixes it.  Doing the fallback all the time
shouldn't hurt, and is one less test.
2005-10-11 07:26:15 +00:00
Rob Landley
6a6798b8e4 Major rewrite of mount, umount, losetup. Untangled lots of code, shrunk
things down a bit, fixed a number of funky corner cases, added support for
several new features (things like mount --move, mount --bind, lazy unounts,
automatic detection of loop mounts, and so on).  Probably broke several
other things, but it's fixable.  (Bang on it, tell me what doesn't work for
you...)

Note: you no longer need to say "-o loop".  It does that for you when
necessary.

Still need to add "user mount" support, which involves making mount suid.  Not
too hard to do under the new infrastructure, just haven't done it yet...

The previous code had the following notes, that belong in the version
control comments:

- * 3/21/1999   Charles P. Wright <cpwright@cpwright.com>
- *             searches through fstab when -a is passed
- *             will try mounting stuff with all fses when passed -t auto
- *
- * 1999-04-17  Dave Cinege...Rewrote -t auto. Fixed ro mtab.
- *
- * 1999-10-07  Erik Andersen <andersen@codepoet.org>.
- *              Rewrite of a lot of code. Removed mtab usage (I plan on
- *              putting it back as a compile-time option some time),
- *              major adjustments to option parsing, and some serious
- *              dieting all around.
- *
- * 1999-11-06  mtab support is back - andersee
- *
- * 2000-01-12   Ben Collins <bcollins@debian.org>, Borrowed utils-linux's
- *              mount to add loop support.
- *
- * 2000-04-30  Dave Cinege <dcinege@psychosis.com>
- *             Rewrote fstab while loop and lower mount section. Can now do
- *             single mounts from fstab. Can override fstab options for single
- *             mount. Common mount_one call for single mounts and 'all'. Fixed
- *             mtab updating and stale entries. Removed 'remount' default.
- *
2005-08-10 20:35:54 +00:00
Paul Fox
e5ba382b99 move the ifdef to after libbb.h include, so it can do some good. 2005-07-27 14:20:52 +00:00
Paul Fox
1429017968 ifdef all of loop.c with CONFIG_FEATURE_MOUNT_LOOP. won't
compile due to CONFIG_FEATURE_MOUNT_LOOP_MAX otherwise.  reported
by Stephane Billiart.
2005-07-22 19:58:32 +00:00
Paul Fox
3f6f3174e9 applying fix from:
0000068: mount limited to max 8 loop devices (patch provided)  

(made minor wording change for config help message)
2005-07-19 20:55:37 +00:00
Eric Andersen
1e4dc96d61 Dear andersen:
Is the change on libbb/loop.c which you commited in 2005/1/3 effective
really?

The __GLIBC__ macro and __UCLIBC__ macro are defined in
feature.h in glibc source, so the change may not be effective.
If you want to check this with __GLIBC__, feature.h header is needed.

Some architectures(e.g. PPC series) need to include linux/posix_types.h
in stead of asm/posix_types.h, so the patch which is attached with
this mail include <linux/posix_types.h>.
2005-01-04 20:37:55 +00:00
Eric Andersen
1271dbb860 perhaps a better fix 2005-01-03 05:50:01 +00:00
Rob Landley
861f0145d3 Workaround for uClibc-specific header problem described here:
http://www.busybox.net/lists/busybox/2004-December/013276.html

Rob
2004-12-09 23:12:00 +00:00
Eric Andersen
0722513497 Use __kernel_old_dev_t for 2.6.x kernels 2004-08-16 08:36:28 +00:00