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Re: Bug: git branch --unset-upstream command can nuke config when disk is full.

From
Ddemerphq <demerphq@gmail.com>
Date
Sep 13, 2017, 14:49 UTC
Message-ID
<CANgJU+WHr2-FjAUUKQ8pUkniczcxrr11dTo_zBeXdTi_su2oUA@mail.gmail.com>
In-Reply-To
<20170913141739.mkmiaud2eemgnbbh@sigill.intra.peff.net>
On 13 September 2017 at 16:17, Jeff King <peff@peff.net> wrote:
> You're welcome to read over the function to double-check, but I just
> looked it over and couldn't find any unchecked writes.
I can look, but I doubt I would notice something you did not.

On the other hand the strace output does show that this is a case where the writes failed, but we still renamed the empty config.lock file into place:

write(3, "[core]\n\tsharedRepository = true\n"..., 288) = -1 ENOSPC (No space left on device) write(3, " merge = refs/heads/yves/"..., 51) = -1 ENOSPC (No space left on device) munmap(0x7f48d9b8c000, 363) = 0 close(3) = 0 rename("/usr/local/git_tree/main/.git/config.lock", "/usr/local/git_tree/main/.git/config") = 0

Full strace is below:
Show 6 quoted lines
>> > Given that your output is consistent with it failing to find the key,
>> > and that the result is an empty file, it sounds like somehow the mmap'd
>> > input appeared empty (but neither open nor fstat nor mmap returned an
>> > error). You're not on any kind of exotic filesystem, are you?
>>
>> I don't think so, but I don't know. Is there a command I can run to check?

I freed up space and things worked, so I somehow doubt the filesystem is at fault. When I then filled up the disk and retried the error was repeatable.

Show 6 quoted lines
>> BTW, with a bit of faffing I can probably recreate this problem.
>> Should I try? Is there something I could do during recreation that
>> would help?
>
> If you think you can reproduce, the output of "strace" on a failing
> invocation would be very interesting.
I can reproduce, see below. Preceded and suffixed by ls on the .git/config file.

I have munged the branch name for privacy reasons, hope that doesn't invalidate the strace utility.

cheers, yves

$ ls -la .git/config
-rw-rw-r-- 1 root users 363 Sep 13 16:36 .git/config
$ strace git branch --unset-upstream
execve("/usr/bin/git", ["git", "branch", "--unset-upstream"], [/* 39
vars */]) = 0
brk(0)                                  = 0x222c000
mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1,
0) = 0x7f48d9b94000
access("/etc/ld.so.preload", R_OK)      = -1 ENOENT (No such file or directory)
open("/etc/ld.so.cache", O_RDONLY)      = 3
fstat(3, {st_mode=S_IFREG|0644, st_size=50300, ...}) = 0
mmap(NULL, 50300, PROT_READ, MAP_PRIVATE, 3, 0) = 0x7f48d9b87000
close(3)                                = 0
open("/lib64/libpcre.so.0", O_RDONLY)   = 3
read(3, "\177ELF\2\1\1\0\0\0\0\0\0\0\0\0\3\0>\0\1\0\0\0@\25\0\0\0\0\0\0"...,
832) = 832
fstat(3, {st_mode=S_IFREG|0755, st_size=183080, ...}) = 0
mmap(NULL, 2278264, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_DENYWRITE, 3,
0) = 0x7f48d9748000
mprotect(0x7f48d9774000, 2097152, PROT_NONE) = 0
mmap(0x7f48d9974000, 4096, PROT_READ|PROT_WRITE,
MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 0x2c000) = 0x7f48d9974000
close(3)                                = 0
open("/lib64/libz.so.1", O_RDONLY)      = 3
read(3, "\177ELF\2\1\1\0\0\0\0\0\0\0\0\0\3\0>\0\1\0\0\0
!\0\0\0\0\0\0"..., 832) = 832
fstat(3, {st_mode=S_IFREG|0755, st_size=88600, ...}) = 0
mmap(NULL, 2183696, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_DENYWRITE, 3,
0) = 0x7f48d9532000
mprotect(0x7f48d9547000, 2093056, PROT_NONE) = 0
mmap(0x7f48d9746000, 8192, PROT_READ|PROT_WRITE,
MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 0x14000) = 0x7f48d9746000
close(3)                                = 0
open("/lib64/libpthread.so.0", O_RDONLY) = 3
read(3, "\177ELF\2\1\1\0\0\0\0\0\0\0\0\0\3\0>\0\1\0\0\0000^\0\0\0\0\0\0"...,
832) = 832
fstat(3, {st_mode=S_IFREG|0755, st_size=143280, ...}) = 0
mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1,
0) = 0x7f48d9b86000
mmap(NULL, 2212848, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_DENYWRITE, 3,
0) = 0x7f48d9315000
mprotect(0x7f48d932c000, 2097152, PROT_NONE) = 0
mmap(0x7f48d952c000, 8192, PROT_READ|PROT_WRITE,
MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 0x17000) = 0x7f48d952c000
mmap(0x7f48d952e000, 13296, PROT_READ|PROT_WRITE,
MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0) = 0x7f48d952e000
close(3)                                = 0
open("/lib64/librt.so.1", O_RDONLY)     = 3
read(3, "\177ELF\2\1\1\0\0\0\0\0\0\0\0\0\3\0>\0\1\0\0\0\240!\0\0\0\0\0\0"...,
832) = 832
fstat(3, {st_mode=S_IFREG|0755, st_size=44472, ...}) = 0
mmap(NULL, 2128816, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_DENYWRITE, 3,
0) = 0x7f48d910d000
mprotect(0x7f48d9114000, 2093056, PROT_NONE) = 0
mmap(0x7f48d9313000, 8192, PROT_READ|PROT_WRITE,
MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 0x6000) = 0x7f48d9313000
close(3)                                = 0
open("/lib64/libc.so.6", O_RDONLY)      = 3
read(3, "\177ELF\2\1\1\3\0\0\0\0\0\0\0\0\3\0>\0\1\0\0\0000\356\1\0\0\0\0\0"...,
832) = 832
fstat(3, {st_mode=S_IFREG|0755, st_size=1924768, ...}) = 0
mmap(NULL, 3750184, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_DENYWRITE, 3,
0) = 0x7f48d8d79000
mprotect(0x7f48d8f03000, 2097152, PROT_NONE) = 0
mmap(0x7f48d9103000, 24576, PROT_READ|PROT_WRITE,
MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 0x18a000) = 0x7f48d9103000
mmap(0x7f48d9109000, 14632, PROT_READ|PROT_WRITE,
MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0) = 0x7f48d9109000
close(3)                                = 0
mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1,
0) = 0x7f48d9b85000
mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1,
0) = 0x7f48d9b84000
mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1,
0) = 0x7f48d9b83000
arch_prctl(ARCH_SET_FS, 0x7f48d9b84700) = 0
mprotect(0x7f48d9103000, 16384, PROT_READ) = 0
mprotect(0x7f48d9313000, 4096, PROT_READ) = 0
mprotect(0x7f48d952c000, 4096, PROT_READ) = 0
mprotect(0x7f48d9746000, 4096, PROT_READ) = 0
mprotect(0x7f48d9b95000, 4096, PROT_READ) = 0
munmap(0x7f48d9b87000, 50300)           = 0
set_tid_address(0x7f48d9b849d0)         = 50373
set_robust_list(0x7f48d9b849e0, 24)     = 0
futex(0x7fff059e43bc, FUTEX_WAKE_PRIVATE, 1) = 0
futex(0x7fff059e43bc, FUTEX_WAIT_BITSET_PRIVATE|FUTEX_CLOCK_REALTIME,
1, NULL, 7f48d9b84700) = -1 EAGAIN (Resource temporarily unavailable)
rt_sigaction(SIGRTMIN, {0x7f48d931acb0, [], SA_RESTORER|SA_SIGINFO,
0x7f48d93247e0}, NULL, 8) = 0
rt_sigaction(SIGRT_1, {0x7f48d931ad40, [],
SA_RESTORER|SA_RESTART|SA_SIGINFO, 0x7f48d93247e0}, NULL, 8) = 0
rt_sigprocmask(SIG_UNBLOCK, [RTMIN RT_1], NULL, 8) = 0
getrlimit(RLIMIT_STACK, {rlim_cur=10240*1024, rlim_max=RLIM64_INFINITY}) = 0
open("/dev/null", O_RDWR)               = 3
close(3)                                = 0
brk(0)                                  = 0x222c000
brk(0x224d000)                          = 0x224d000
open("/usr/lib/locale/locale-archive", O_RDONLY) = 3
fstat(3, {st_mode=S_IFREG|0644, st_size=99170352, ...}) = 0
mmap(NULL, 99170352, PROT_READ, MAP_PRIVATE, 3, 0) = 0x7f48d2ee5000
close(3)                                = 0
open("/usr/lib64/gconv/gconv-modules.cache", O_RDONLY) = 3
fstat(3, {st_mode=S_IFREG|0644, st_size=26060, ...}) = 0
mmap(NULL, 26060, PROT_READ, MAP_SHARED, 3, 0) = 0x7f48d9b8d000
close(3)                                = 0
futex(0x7f48d9108828, FUTEX_WAKE_PRIVATE, 2147483647) = 0
rt_sigprocmask(SIG_UNBLOCK, [PIPE], NULL, 8) = 0
rt_sigaction(SIGPIPE, {SIG_DFL, [PIPE], SA_RESTORER|SA_RESTART,
0x7f48d8dab510}, {SIG_DFL, [], 0}, 8) = 0
getcwd("/usr/local/git_tree/main", 129) = 25
stat("/usr/local/git_tree/main", {st_mode=S_IFDIR|S_ISGID|0775,
st_size=4096, ...}) = 0
stat("/usr/local/git_tree/main/.git", {st_mode=S_IFDIR|S_ISGID|0775,
st_size=4096, ...}) = 0
lstat("/usr/local/git_tree/main/.git/HEAD", {st_mode=S_IFREG|0664,
st_size=39, ...}) = 0
open("/usr/local/git_tree/main/.git/HEAD", O_RDONLY) = 3
read(3, "ref: refs/heads/yves/simple_proj"..., 255) = 39
read(3, "", 216)                        = 0
close(3)                                = 0
lstat("/usr/local/git_tree/main/.git/commondir", 0x7fff059e3ec0) = -1
ENOENT (No such file or directory)
access("/usr/local/git_tree/main/.git/objects", X_OK) = 0
access("/usr/local/git_tree/main/.git/refs", X_OK) = 0
lstat(".git/commondir", 0x7fff059e3ef0) = -1 ENOENT (No such file or directory)
open(".git/config", O_RDONLY)           = 3
fstat(3, {st_mode=S_IFREG|0664, st_size=363, ...}) = 0
fstat(3, {st_mode=S_IFREG|0664, st_size=363, ...}) = 0
mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1,
0) = 0x7f48d9b8c000
read(3, "[core]\n\tsharedRepository = true\n"..., 4096) = 363
read(3, "", 4096)                       = 0
close(3)                                = 0
munmap(0x7f48d9b8c000, 4096)            = 0
getcwd("/usr/local/git_tree/main", 129) = 25
stat(".git", {st_mode=S_IFDIR|S_ISGID|0775, st_size=4096, ...}) = 0
lstat(".git/commondir", 0x7fff059e3f50) = -1 ENOENT (No such file or directory)
access("/etc/gitconfig", R_OK)          = 0
open("/etc/gitconfig", O_RDONLY)        = 3
fstat(3, {st_mode=S_IFREG|0644, st_size=1353, ...}) = 0
fstat(3, {st_mode=S_IFREG|0644, st_size=1353, ...}) = 0
mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1,
0) = 0x7f48d9b8c000
read(3, "################################"..., 4096) = 1353
read(3, "", 4096)                       = 0
close(3)                                = 0
munmap(0x7f48d9b8c000, 4096)            = 0
access("/home/yorton/.config/git/config", R_OK) = -1 ENOENT (No such
file or directory)
access("/home/yorton/.gitconfig", R_OK) = 0
open("/home/yorton/.gitconfig", O_RDONLY) = 3
fstat(3, {st_mode=S_IFREG|0644, st_size=377, ...}) = 0
fstat(3, {st_mode=S_IFREG|0644, st_size=377, ...}) = 0
mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1,
0) = 0x7f48d9b8c000
read(3, "[alias]\n\thist = log --graph --co"..., 4096) = 377
read(3, "", 4096)                       = 0
close(3)                                = 0
munmap(0x7f48d9b8c000, 4096)            = 0
access(".git/config", R_OK)             = 0
open(".git/config", O_RDONLY)           = 3
fstat(3, {st_mode=S_IFREG|0664, st_size=363, ...}) = 0
fstat(3, {st_mode=S_IFREG|0664, st_size=363, ...}) = 0
mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1,
0) = 0x7f48d9b8c000
read(3, "[core]\n\tsharedRepository = true\n"..., 4096) = 363
read(3, "", 4096)                       = 0
close(3)                                = 0
munmap(0x7f48d9b8c000, 4096)            = 0
open("/usr/share/locale/locale.alias", O_RDONLY|O_CLOEXEC) = 3
fstat(3, {st_mode=S_IFREG|0644, st_size=2512, ...}) = 0
mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1,
0) = 0x7f48d9b8c000
read(3, "# Locale name alias data base.\n#"..., 4096) = 2512
read(3, "", 4096)                       = 0
close(3)                                = 0
munmap(0x7f48d9b8c000, 4096)            = 0
open("/usr/share/locale/en_CA.utf8/LC_MESSAGES/git.mo", O_RDONLY) = -1
ENOENT (No such file or directory)
open("/usr/share/locale/en_CA/LC_MESSAGES/git.mo", O_RDONLY) = -1
ENOENT (No such file or directory)
open("/usr/share/locale/en.utf8/LC_MESSAGES/git.mo", O_RDONLY) = -1
ENOENT (No such file or directory)
open("/usr/share/locale/en/LC_MESSAGES/git.mo", O_RDONLY) = -1 ENOENT
(No such file or directory)
access("/etc/gitconfig", R_OK)          = 0
open("/etc/gitconfig", O_RDONLY)        = 3
fstat(3, {st_mode=S_IFREG|0644, st_size=1353, ...}) = 0
fstat(3, {st_mode=S_IFREG|0644, st_size=1353, ...}) = 0
mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1,
0) = 0x7f48d9b8c000
read(3, "################################"..., 4096) = 1353
read(3, "", 4096)                       = 0
close(3)                                = 0
munmap(0x7f48d9b8c000, 4096)            = 0
access("/home/yorton/.config/git/config", R_OK) = -1 ENOENT (No such
file or directory)
access("/home/yorton/.gitconfig", R_OK) = 0
open("/home/yorton/.gitconfig", O_RDONLY) = 3
fstat(3, {st_mode=S_IFREG|0644, st_size=377, ...}) = 0
fstat(3, {st_mode=S_IFREG|0644, st_size=377, ...}) = 0
mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1,
0) = 0x7f48d9b8c000
read(3, "[alias]\n\thist = log --graph --co"..., 4096) = 377
read(3, "", 4096)                       = 0
close(3)                                = 0
munmap(0x7f48d9b8c000, 4096)            = 0
access(".git/config", R_OK)             = 0
open(".git/config", O_RDONLY)           = 3
fstat(3, {st_mode=S_IFREG|0664, st_size=363, ...}) = 0
fstat(3, {st_mode=S_IFREG|0664, st_size=363, ...}) = 0
mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1,
0) = 0x7f48d9b8c000
read(3, "[core]\n\tsharedRepository = true\n"..., 4096) = 363
read(3, "", 4096)                       = 0
close(3)                                = 0
munmap(0x7f48d9b8c000, 4096)            = 0
lstat(".git/commondir", 0x7fff059e3590) = -1 ENOENT (No such file or directory)
lstat(".git/HEAD", {st_mode=S_IFREG|0664, st_size=39, ...}) = 0
open(".git/HEAD", O_RDONLY)             = 3
read(3, "ref: refs/heads/yves/xxx"..., 256) = 39
read(3, "", 217)                        = 0
close(3)                                = 0
lstat(".git/refs/heads/yves/xxx", 0x7fff059e3580) = -1 ENOENT (No such
file or directory)
open(".git/packed-refs", O_RDONLY)      = 3
fstat(3, {st_mode=S_IFREG|0664, st_size=231354, ...}) = 0
fstat(3, {st_mode=S_IFREG|0664, st_size=231354, ...}) = 0
fstat(3, {st_mode=S_IFREG|0664, st_size=231354, ...}) = 0
mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1,
0) = 0x7f48d9b8c000
read(3, "# pack-refs with: peeled fully-p"..., 4096) = 4096
read(3, "1a5c122f68f04fae374ac3cdf11\n14e0"..., 4096) = 4096
read(3, "b16f20dde39f97ef2869296\nba29d061"..., 4096) = 4096
read(3, "6-141414\n^29ba731b77bb5f5c15644d"..., 4096) = 4096
read(3, "df2d5e\n3cd1ca6cffc2ce48ecc09c0c1"..., 4096) = 4096
read(3, "fd414d360b4d742e8711fe8093a09fa "..., 4096) = 4096
read(3, "pit-20170511-164552\n^cb28295c135"..., 4096) = 4096
read(3, "4a4cb2cf8620771feb\n41b2f890ea48b"..., 4096) = 4096
read(3, "\n^9827bb20ed16ec66dd510d72d779c6"..., 4096) = 4096
read(3, "-160507\n^56472ff6a42c58dee27d337"..., 4096) = 4096
read(3, "0d01a69f3c0\nef9052d4b9c0e143a5f0"..., 4096) = 4096
read(3, "/tags/dummyapp-20170609-182243_a"..., 4096) = 4096
read(3, "5418485a012396832faedc5\nc697717c"..., 4096) = 4096
read(3, "3-141556\n^69219f5ddd74c43d5574e5"..., 4096) = 4096
read(3, "0602-122026\n^4cbb642a2b3cb305336"..., 4096) = 4096
read(3, "a9bee28a76502716da588fd2fc22020a"..., 4096) = 4096
read(3, "73a677f refs/tags/events-2016090"..., 4096) = 4096
read(3, "3be9fd87d5bf6217aaf195d5\n650866a"..., 4096) = 4096
read(3, "a95cda22bc90a79\n4f3a36e9adac266f"..., 4096) = 4096
read(3, "ec1097435aeed7ed8\n7a2c97e8ad1a9f"..., 4096) = 4096
read(3, "dba7614549cec3ed80803b6b01161c3d"..., 4096) = 4096
read(3, "4ef8e8f\n7e3c15cd86655da442c48ba7"..., 4096) = 4096
read(3, "1d057a4b7dc47ac09f40a8d31916218\n"..., 4096) = 4096
read(3, "s/tags/intercomcron-20170615-110"..., 4096) = 4096
read(3, "\n^43f080925840cf77ae016fa93ecbdf"..., 4096) = 4096
read(3, "gs/logproc-20161230-121402\n^a25f"..., 4096) = 4096
read(3, "2d55c54c708fca2cfe726e72d86ad50 "..., 4096) = 4096
read(3, "70612-163608\n^614fcefc7f4c39b12f"..., 4096) = 4096
read(3, "ilebuild-20170512-145808\n^47a87c"..., 4096) = 4096
brk(0x226e000)                          = 0x226e000
read(3, "7a428de652f5a3c9c4\n214d8d1128260"..., 4096) = 4096
read(3, "\n^e5486659e4bad48a3fb1177b619f11"..., 4096) = 4096
read(3, "91f33991c3efed545f51 refs/tags/p"..., 4096) = 4096
read(3, "08d313fb454\nefe6a551adac01f51538"..., 4096) = 4096
read(3, "/ppcapp-20170628-111257\n^f56019d"..., 4096) = 4096
read(3, "b50901 refs/tags/provdash-201706"..., 4096) = 4096
read(3, "7 refs/tags/rtmapp-20170613-1102"..., 4096) = 4096
read(3, "-192153\n^296cc5ffc1c84b049fd0a15"..., 4096) = 4096
read(3, "a6\nda231495f5708ecdafe41aedf28a4"..., 4096) = 4096
read(3, "202\n^70ebec46ba2859c12b67a6dca82"..., 4096) = 4096
read(3, "9d54a38eeff507e45d\n9d93a8eaf70d3"..., 4096) = 4096
read(3, "ecure-hmsapp-20161021-181248\n^a5"..., 4096) = 4096
read(3, "0111-134153\n^13d748af46df47b5315"..., 4096) = 4096
read(3, "1 refs/tags/soylent-20170606-154"..., 4096) = 4096
read(3, "tags/statprofileapp-20161104-125"..., 4096) = 4096
read(3, "tags/substreamproc-20170214-1429"..., 4096) = 4096
read(3, "efs/tags/suite_partner_sites-201"..., 4096) = 4096
read(3, "167 refs/tags/tokenauth-20160929"..., 4096) = 4096
read(3, "640\n^00b52cdaaaf3c55e069cb62740d"..., 4096) = 4096
read(3, "9753e496ebbf7b05f009dd32\ndb917ed"..., 4096) = 4096
read(3, "8cc96a8a9313d82cc4c91d2ddc31613b"..., 4096) = 4096
read(3, "2ad87b80a7a0\n56519d1a3c4fe5cdcc3"..., 4096) = 4096
read(3, " refs/tags/xml-secure-mobile-201"..., 4096) = 4096
read(3, "794a5b25d4b5d411cc736298a\nb4cb1c"..., 4096) = 4096
read(3, "057d938c27f8b16e6ef9839874f696a2"..., 4096) = 4096
read(3, "3f3259ffc0262e4bf56f4eec01c76ac8"..., 4096) = 4096
read(3, "\n^dbab804616296abf788d4a1d991b3b"..., 4096) = 4096
read(3, "dad60d1e168e7d7de94e3da1 refs/ta"..., 4096) = 1978
read(3, "", 4096)                       = 0
close(3)                                = 0
munmap(0x7f48d9b8c000, 4096)            = 0
lstat(".git/HEAD", {st_mode=S_IFREG|0664, st_size=39, ...}) = 0
open(".git/HEAD", O_RDONLY)             = 3
read(3, "ref: refs/heads/yves/xxx"..., 256) = 39
read(3, "", 217)                        = 0
close(3)                                = 0
lstat(".git/refs/heads/yves/xxx", 0x7fff059e34b0) = -1 ENOENT (No such
file or directory)
stat(".git/packed-refs", {st_mode=S_IFREG|0664, st_size=231354, ...}) = 0
readlink(".git/config", 0x2267b40, 32)  = -1 EINVAL (Invalid argument)
rt_sigaction(SIGINT, {0x54a550, [INT], SA_RESTORER|SA_RESTART,
0x7f48d8dab510}, {SIG_DFL, [], 0}, 8) = 0
rt_sigaction(SIGHUP, {0x54a550, [HUP], SA_RESTORER|SA_RESTART,
0x7f48d8dab510}, {SIG_DFL, [], 0}, 8) = 0
rt_sigaction(SIGTERM, {0x54a550, [TERM], SA_RESTORER|SA_RESTART,
0x7f48d8dab510}, {SIG_DFL, [], 0}, 8) = 0
rt_sigaction(SIGQUIT, {0x54a550, [QUIT], SA_RESTORER|SA_RESTART,
0x7f48d8dab510}, {SIG_DFL, [], 0}, 8) = 0
rt_sigaction(SIGPIPE, {0x54a550, [PIPE], SA_RESTORER|SA_RESTART,
0x7f48d8dab510}, {SIG_DFL, [PIPE], SA_RESTORER|SA_RESTART,
0x7f48d8dab510}, 8) = 0
getcwd("/usr/local/git_tree/main", 129) = 25
open("/usr/local/git_tree/main/.git/config.lock",
O_RDWR|O_CREAT|O_EXCL|O_CLOEXEC, 0666) = 3
lstat("/usr/local/git_tree/main/.git/config.lock",
{st_mode=S_IFREG|0664, st_size=0, ...}) = 0
open(".git/config", O_RDONLY)           = 4
open(".git/config", O_RDONLY)           = 5
fstat(5, {st_mode=S_IFREG|0664, st_size=363, ...}) = 0
fstat(5, {st_mode=S_IFREG|0664, st_size=363, ...}) = 0
mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1,
0) = 0x7f48d9b8c000
read(5, "[core]\n\tsharedRepository = true\n"..., 4096) = 363
lseek(5, 0, SEEK_CUR)                   = 363
read(5, "", 4096)                       = 0
close(5)                                = 0
munmap(0x7f48d9b8c000, 4096)            = 0
fstat(4, {st_mode=S_IFREG|0664, st_size=363, ...}) = 0
mmap(NULL, 363, PROT_READ, MAP_PRIVATE, 4, 0) = 0x7f48d9b8c000
close(4)                                = 0
chmod("/usr/local/git_tree/main/.git/config.lock", 0664) = 0
write(3, "[core]\n\tsharedRepository = true\n"..., 288) = -1 ENOSPC
(No space left on device)
write(3, "        merge = refs/heads/yves/"..., 51) = -1 ENOSPC (No
space left on device)
munmap(0x7f48d9b8c000, 363)             = 0
close(3)                                = 0
rename("/usr/local/git_tree/main/.git/config.lock",
"/usr/local/git_tree/main/.git/config") = 0
readlink(".git/config", 0x2230d00, 32)  = -1 EINVAL (Invalid argument)
getcwd("/usr/local/git_tree/main", 129) = 25
open("/usr/local/git_tree/main/.git/config.lock",
O_RDWR|O_CREAT|O_EXCL|O_CLOEXEC, 0666) = 3
lstat("/usr/local/git_tree/main/.git/config.lock",
{st_mode=S_IFREG|0664, st_size=0, ...}) = 0
open(".git/config", O_RDONLY)           = 4
open(".git/config", O_RDONLY)           = 5
fstat(5, {st_mode=S_IFREG|0664, st_size=0, ...}) = 0
fstat(5, {st_mode=S_IFREG|0664, st_size=0, ...}) = 0
mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1,
0) = 0x7f48d9b8c000
read(5, "", 4096)                       = 0
close(5)                                = 0
munmap(0x7f48d9b8c000, 4096)            = 0
close(3)                                = 0
unlink("/usr/local/git_tree/main/.git/config.lock") = 0
close(4)                                = 0
write(2, "fatal: could not unset 'branch.y"..., 61fatal: could not
unset 'branch.yves/xxx.merge'
) = 61
exit_group(128)                         = ?
+++ exited with 128 +++
$ ls -la .git/config
-rw-rw-r-- 1 yorton users 0 Sep 13 16:38 .git/config
-- 
perl -Mre=debug -e "/just|another|perl|hacker/"
Previous: Jeff KingNext: Jeff King
Message 5 of 46 in “Bug: git branch --unset-upstream command can nuke config when disk is full.”
  1. demerphqSep 13, 2017
  2. Jeff KingSep 13, 2017
  3. demerphqSep 13, 2017
  4. Jeff KingSep 13, 2017
  5. demerphqSep 13, 2017
  6. Jeff KingSep 13, 2017
  7. demerphqSep 13, 2017
  8. Jeff KingSep 13, 2017
  9. demerphqSep 13, 2017
  10. 0/7 config.c may fail to notice some write() failuresJeff King, Sep 13, 2017
  11. 1/7 config: avoid "write_in_full(fd, buf, len) < len" patternJeff King, Sep 13, 2017
  12. Jonathan NiederSep 13, 2017
  13. Jeff KingSep 13, 2017
  14. Jonathan NiederSep 13, 2017
  15. Jeff KingSep 13, 2017
  16. config: avoid "write_in_full(fd, buf, len) < len" patternJeff King, Sep 13, 2017
  17. Jonathan NiederSep 13, 2017
  18. Jeff KingSep 13, 2017
  19. Jonathan NiederSep 13, 2017
  20. Jonathan NiederSep 13, 2017
  21. Ramsay JonesSep 13, 2017
  22. Ramsay JonesSep 13, 2017
  23. Jeff KingSep 15, 2017
  24. Ramsay JonesSep 15, 2017
  25. Junio C HamanoSep 13, 2017
  26. 2/7 get-tar-commit-id: check write_in_full() return against 0Jeff King, Sep 13, 2017
  27. Jonathan NiederSep 13, 2017
  28. Jeff KingSep 13, 2017
  29. Jeff KingSep 13, 2017
  30. Jonathan NiederSep 13, 2017
  31. Jeff KingSep 15, 2017
  32. 3/7 avoid "write_in_full(fd, buf, len) != len" patternJeff King, Sep 13, 2017
  33. Jonathan NiederSep 13, 2017
  34. Jeff KingSep 15, 2017
  35. 4/7 convert less-trivial versions of "write_in_full() != len"Jeff King, Sep 13, 2017
  36. Jonathan NiederSep 13, 2017
  37. 5/7 pkt-line: check write_in_full() errors against "< 0"Jeff King, Sep 13, 2017
  38. Jonathan NiederSep 13, 2017
  39. 6/7 notes-merge: use ssize_t for write_in_full() return valueJeff King, Sep 13, 2017
  40. Jonathan NiederSep 13, 2017
  41. Jeff KingSep 15, 2017
  42. 7/7 config: flip return value of store_write_*()Jeff King, Sep 13, 2017
  43. Jonathan NiederSep 13, 2017
  44. Jeff KingSep 15, 2017
  45. 8/7 read_pack_header: handle signed/unsigned comparison in read resultJeff King, Sep 13, 2017
  46. Jonathan NiederSep 13, 2017

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