Bug 203233

Description of problem:

1) The RPM database build (sometime after firstboot) failed because
   I had a '/var' that was too small.
2) After some time, I noticed that there was a problem with 'rpm',
   as there were a couple of cron-started 'rpm' processes hanging around
   that I had to 'kill -9'. 'rpm' did not work, seemed to be hanging (correct
   hunch, as it was waiting, see below). CTRL-C or kill were useless to stop
   'rpm', only 'kill -9' stopped the process. This occurred for 'rpm --query'
   and 'yum' and 'rpm --rebuilddb' (even after an 'rpm --initdb'). Blimey!
3) Looking further, files in '/var/lib/rpm' called '__db.XXX' seemed to 
   bother 'rpm'. Note that these files also are there after a *successful*
   database build. 'gdb' and 'strace' show that 'rpm' works a bit, then waits
   on a futex, probably thinking that some other process is still working on
   the database.
4) After removal of the /var/lib/rpm/__db.XXX files and an 'rpm --rebuilddb',
   things are working fine.

Conclusion: The mechanism for exclusive access to the RPM db needs some kind
of review.

strace of a hanging 'rpm --rebuilddb' yields:

<..snip...>
munmap(0xb7bb1000, 4096)                = 0
stat64("/var/lib/rpmrebuilddb.4128/DB_CONFIG", 0xbfd7f5cc) = -1 ENOENT (No such
file or directory)
open("/var/lib/rpmrebuilddb.4128/DB_CONFIG", O_RDONLY|O_LARGEFILE) = -1 ENOENT
(No such file or directory)
stat64("/var/lib/rpmrebuilddb.4128/__db.001", 0xbfd7f64c) = -1 ENOENT (No such
file or directory)
open("/var/lib/rpmrebuilddb.4128/__db.001", O_RDWR|O_CREAT|O_EXCL|O_LARGEFILE,
0644) = 5
fcntl64(5, F_SETFD, FD_CLOEXEC)         = 0
open("/var/lib/rpmrebuilddb.4128/__db.001", O_RDWR|O_CREAT|O_LARGEFILE, 0644) = 6
fcntl64(6, F_SETFD, FD_CLOEXEC)         = 0
_llseek(6, 0, [0], SEEK_END)            = 0
_llseek(6, 16384, [16384], SEEK_CUR)    = 0
write(6, "\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0"..., 8192) = 8192
mmap2(NULL, 24576, PROT_READ|PROT_WRITE, MAP_SHARED, 6, 0) = 0xb7bac000
close(6)                                = 0
gettimeofday({1156006124, 976551}, NULL) = 0
close(5)                                = 0
stat64("/var/lib/rpmrebuilddb.4128/__db.002", 0xbfd7f66c) = -1 ENOENT (No such
file or directory)
open("/var/lib/rpmrebuilddb.4128/__db.002", O_RDWR|O_CREAT|O_LARGEFILE, 0644) = 5
fcntl64(5, F_SETFD, FD_CLOEXEC)         = 0
_llseek(5, 0, [0], SEEK_END)            = 0
_llseek(5, 1310720, [1310720], SEEK_CUR) = 0
write(5, "\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0"..., 8192) = 8192
mmap2(NULL, 1318912, PROT_READ|PROT_WRITE, MAP_SHARED, 5, 0) = 0xb7a6a000
close(5)                                = 0
stat64("/var/lib/rpmrebuilddb.4128/Packages", 0xbfd7f46c) = -1 ENOENT (No such
file or directory)
open("/usr/lib/gconv/gconv-modules.cache", O_RDONLY) = 5
fstat64(5, {st_mode=S_IFREG|0644, st_size=25404, ...}) = 0
mmap2(NULL, 25404, PROT_READ, MAP_SHARED, 5, 0) = 0xb7a63000
close(5)                                = 0
futex(0xce3a4c, FUTEX_WAKE, 2147483647) = 0
open("/var/lib/rpmrebuilddb.4128/__db.Packages",
O_RDWR|O_CREAT|O_EXCL|O_LARGEFILE, 0644) = 5
fcntl64(5, F_SETFD, FD_CLOEXEC)         = 0
fstat64(5, {st_mode=S_IFREG|0644, st_size=0, ...}) = 0
stat64("/var/lib/rpmrebuilddb.4128/__db.Packages", {st_mode=S_IFREG|0644,
st_size=0, ...}) = 0
gettimeofday({1156006124, 979843}, NULL) = 0
_llseek(5, 0, [0], SEEK_SET)            = 0
write(5, "\0\0\0\0\1\0\0\0\0\0\0\0a\25\6\0\10\0\0\0\0\20\0\0\0\10"..., 4096) = 4096
_llseek(5, 8192, [8192], SEEK_SET)      = 0
write(5, "\0\0\0\0\1\0\0\0\2\0\0\0\0\0\0\0\0\0\0\0\0\0\0\20\0\2\0"..., 4096) = 4096
close(5)                                = 0
stat64("/var/lib/rpmrebuilddb.4128/Packages", 0xbfd7f46c) = -1 ENOENT (No such
file or directory)
rename("/var/lib/rpmrebuilddb.4128/__db.Packages",
"/var/lib/rpmrebuilddb.4128/Packages") = 0
open("/var/lib/rpmrebuilddb.4128/Packages", O_RDWR|O_LARGEFILE) = 5
fcntl64(5, F_SETFD, FD_CLOEXEC)         = 0
fstat64(5, {st_mode=S_IFREG|0644, st_size=12288, ...}) = 0
pread64(5, "\0\0\0\0\1\0\0\0\0\0\0\0a\25\6\0\10\0\0\0\0\20\0\0\0\10"..., 4096,
0) = 4096
rt_sigprocmask(SIG_BLOCK, ~[RTMIN RT_1], [], 8) = 0
rt_sigprocmask(SIG_SETMASK, [], NULL, 8) = 0
mmap2(NULL, 143360, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) =
0xb7a40000
futex(0xb7d5ecd0, FUTEX_WAIT, 2, NULL <unfinished ...>


stacktrace for 'rpm --rebuilddb'

#0  0x00d7e402 in ?? ()
#1  0x00de77ae in __lll_mutex_lock_wait () from /lib/libpthread.so.0
#2  0x00de416c in _L_mutex_lock_70 () from /lib/libpthread.so.0
#3  0x00de3fb8 in pthread_mutex_lock () from /lib/libpthread.so.0
#4  0x0047c4bf in __db_pthread_mutex_lock_rpmdb () from /usr/lib/librpmdb-4.4.so
#5  0x0051dddb in __memp_fget_rpmdb () from /usr/lib/librpmdb-4.4.so
#6  0x004ee850 in __db_goff_rpmdb () from /usr/lib/librpmdb-4.4.so
#7  0x004f615d in __db_ret_rpmdb () from /usr/lib/librpmdb-4.4.so
#8  0x004e148d in __db_c_get_rpmdb () from /usr/lib/librpmdb-4.4.so
#9  0x004e7946 in __db_c_get_pp_rpmdb () from /usr/lib/librpmdb-4.4.so
#10 0x00477946 in tagType () from /usr/lib/librpmdb-4.4.so
#11 0x00471f73 in rpmdbNextIterator () from /usr/lib/librpmdb-4.4.so
#12 0x00475d44 in rpmdbRebuild () from /usr/lib/librpmdb-4.4.so
#13 0x0069ed56 in rpmtsRebuildDB () from /usr/lib/librpm-4.4.so
#14 0x08049992 in ?? ()
#15 0x00bc97e4 in __libc_start_main () from /lib/libc.so.6
#16 0x08049231 in ?? ()

Version-Release number of selected component (if applicable):

   rpm-4.4.2-15.2

How reproducible:

   Did not try