Re: [PATCH 5/6] fts: three levels of leaf optimization

[Kamil Dudka]

On Friday, April 6, 2018 9:27:07 AM CEST Kamil Dudka wrote:
> On Thursday, April 5, 2018 5:49:15 PM CEST Paul Eggert wrote:
> > On 04/05/2018 05:44 AM, Kamil Dudka wrote:
> > > Does this change (intentionally?) enable leaf optimization for CIFS?
> > 
> > No, I wasn't thinking about CIFS when I wrote that. Thanks for reporting
> > it. I installed the attached to try to fix this. I have not tested it
> > with CIFS.
> 
> Thanks!  I have provided the Fedora user with a patched build of findutils,
> will let you know when I have some feedback on that.
> 
> Kamil

We have two independent testers of a debug build that contains the above
patch.  Unfortunately, the patch did not prevent 'find' from aborting.
There must be some programming mistake in the code that checks whether
the leaf optimization should be enabled or not.

>From both the captured strace outputs it is obvious that fstatfs() is not
called on the CIFS mount points at all.  For example, if 'find' traverses
/mnt/iamsbackup (where /mnt is an XFS file system and /mnt/iamsbackup a CIFS
file system), it calls fstatfs() on the file descriptor of /mnt despite
/mnt/iamsbackup already has its own file descriptor.  Then it aborts while
trying to leaf-optimize the traversal of /mnt/iamsbackup/... because 'find'
thinks it is traversing an XFS file system:

Any idea what could have gone wrong?

Kamil


[...]
newfstatat(AT_FDCWD, "/mnt", {st_mode=S_IFDIR|0755, st_size=24, ...}, 
AT_SYMLINK_NOFOLLOW) = 0
fcntl(4, F_DUPFD_CLOEXEC, 3)            = 5
getdents(4, /* 3 entries */, 32768)     = 80
getdents(4, /* 0 entries */, 32768)     = 0
close(4)                                = 0
newfstatat(5, "iamsbackup", {st_mode=S_IFDIR|0770, st_size=4096, ...}, 
AT_SYMLINK_NOFOLLOW) = 0
fcntl(5, F_DUPFD_CLOEXEC, 0)            = 4
openat(5, "iamsbackup", 
O_RDONLY|O_NOCTTY|O_NONBLOCK|O_NOFOLLOW|O_CLOEXEC|O_DIRECTORY) = 6
fstat(6, {st_mode=S_IFDIR|0770, st_size=4096, ...}) = 0
fcntl(6, F_GETFL)                       = 0x38800 (flags 
O_RDONLY|O_NONBLOCK|O_LARGEFILE|O_NOFOLLOW|O_DIRECTORY)
fcntl(6, F_SETFD, FD_CLOEXEC)           = 0
newfstatat(5, "iamsbackup", {st_mode=S_IFDIR|0770, st_size=4096, ...}, 
AT_SYMLINK_NOFOLLOW) = 0
fstatfs(5, {f_type=XFS_SB_MAGIC, f_bsize=4096, f_blocks=239342405, 
f_bfree=237648468, f_bavail=237648468, f_files=478918656, f_ffree=478852745, 
f_fsid={val=[2430, 0]}, f_namelen=255, f_frsi
fcntl(6, F_DUPFD_CLOEXEC, 3)            = 7
getdents(6, /* 9 entries */, 32768)     = 296
getdents(6, /* 0 entries */, 32768)     = 0
close(6)                                = 0
close(4)                                = 0
fcntl(7, F_DUPFD_CLOEXEC, 0)            = 4
newfstatat(7, "latestBackup", {st_mode=S_IFDIR|0770, st_size=0, ...}, 
AT_SYMLINK_NOFOLLOW) = 0
openat(7, "latestBackup", 
O_RDONLY|O_NOCTTY|O_NONBLOCK|O_NOFOLLOW|O_CLOEXEC|O_DIRECTORY) = 6
fstat(6, {st_mode=S_IFDIR|0770, st_size=0, ...}) = 0
fcntl(6, F_GETFL)                       = 0x38800 (flags 
O_RDONLY|O_NONBLOCK|O_LARGEFILE|O_NOFOLLOW|O_DIRECTORY)
fcntl(6, F_SETFD, FD_CLOEXEC)           = 0
rt_sigprocmask(SIG_UNBLOCK, [ABRT], NULL, 8) = 0
rt_sigprocmask(SIG_BLOCK, ~[RTMIN RT_1], [], 8) = 0
getpid()                                = 7826
gettid()                                = 7826
tgkill(7826, 7826, SIGABRT)             = 0
rt_sigprocmask(SIG_SETMASK, [], NULL, 8) = 0
--- SIGABRT {si_signo=SIGABRT, si_code=SI_TKILL, si_pid=7826, si_uid=1001} ---
+++ killed by SIGABRT (core dumped) +++