svn commit: r350402 - stable/11/cddl/contrib/opensolaris/lib/libzfs/common
Slawa Olhovchenkov
slw at zxy.spb.ru
Tue Aug 6 12:31:40 UTC 2019
On Mon, Jul 29, 2019 at 08:23:15AM +0000, Baptiste Daroussin wrote:
still broken:
# ls -l /poudriere/ports/default
ls: /poudriere/ports/default: No such file or directory
# zfs list
NAME USED AVAIL REFER MOUNTPOINT
DB 256G 643G 96K /DB
DB/var 255G 643G 96K /DB/var
DB/var/db 255G 643G 96K /DB/var/db
DB/var/db/mysql 255G 643G 255G /var/db/mysql
DB/var/db/mysql/MyISAM 96K 643G 96K /var/db/mysql/MyISAM
DB/var/db/mysql/innodb-logs 128M 643G 128M /var/db/mysql/innodb-logs
zroot 2.94T 551G 112K /ZROOT
zroot/ROOT 352M 551G 352M /
zroot/home 144K 551G 144K legacy
zroot/poudriere 5.41G 551G 128K /poudriere
zroot/poudriere/data 608M 551G 608M /poudriere/data
zroot/poudriere/jails 2.71G 551G 128K /poudriere/jails
zroot/poudriere/jails/10amd64 2.71G 551G 2.71G /poudriere/jails/10amd64
zroot/poudriere/ports 2.10G 551G 96K /poudriere/ports
zroot/poudriere/ports/default 2.10G 551G 2.10G /poudriere/ports/default
zroot/tmp 6.94G 551G 6.94G /tmp
zroot/usr 630G 551G 57.0G /usr
zroot/usr/local 543G 551G 543G /usr/local
zroot/usr/obj 19.2G 551G 19.2G /usr/obj
zroot/usr/ports 4.80G 551G 1.07G /usr/ports
zroot/usr/ports/distfiles 3.72G 551G 3.72G /usr/ports/distfiles
zroot/usr/ports/packages 7.04M 551G 7.04M /usr/ports/packages
zroot/usr/src 5.51G 551G 5.51G /usr/src
zroot/var 345G 551G 1.10G /var
zroot/var/crash 148K 551G 148K /var/crash
zroot/var/db 58.4G 551G 3.92G /var/db
zroot/var/db/mysql 54.4G 551G 54.2G /var/db/mysql
zroot/var/db/mysql/MyISAM 144K 551G 144K /var/db/mysql/MyISAM
zroot/var/db/mysql/innodb-logs 128M 551G 128M /var/db/mysql/innodb-logs
zroot/var/db/pkg 69.6M 551G 69.6M /var/db/pkg
zroot/var/empty 144K 551G 144K /var/empty
zroot/var/log 248G 551G 248G /var/log
zroot/var/mail 148K 551G 148K /var/mail
zroot/var/run 444K 551G 444K /var/run
zroot/var/spool 37.3G 551G 37.3G /var/spool
zroot/var/tmp 548K 551G 548K /var/tmp
zroot/www 1.98T 551G 160K /www
zroot/www/dev0 1.59G 551G 1.59G /www/dev0
zroot/www/dev1 1.48G 551G 1.48G /www/dev1
zroot/www/dev2 1.48G 551G 1.48G /www/dev2
zroot/www/dev3 1.59G 551G 1.59G /www/dev3
zroot/www/dev4 1.49G 551G 1.49G /www/dev4
zroot/www/dev5 1.47G 551G 1.47G /www/dev5
zroot/www/komandirovka 186G 551G 30.9G /www/komandirovka
zroot/www/komandirovka_old 1.79T 551G 1.79T /www/komandirovka_old
> Author: bapt
> Date: Mon Jul 29 08:23:15 2019
> New Revision: 350402
> URL: https://svnweb.freebsd.org/changeset/base/350402
>
> Log:
> MFC r350358:
>
> Fix a bug introduced with parallel mounting of zfs
>
> Incorporate a fix from zol:
> https://github.com/zfsonlinux/zfs/commit/ab5036df1ccbe1b18c1ce6160b5829e8039d94ce
>
> commit log from upstream:
> Fix race in parallel mount's thread dispatching algorithm
>
> Strategy of parallel mount is as follows.
>
> 1) Initial thread dispatching is to select sets of mount points that
> don't have dependencies on other sets, hence threads can/should run
> lock-less and shouldn't race with other threads for other sets. Each
> thread dispatched corresponds to top level directory which may or may
> not have datasets to be mounted on sub directories.
>
> 2) Subsequent recursive thread dispatching for each thread from 1)
> is to mount datasets for each set of mount points. The mount points
> within each set have dependencies (i.e. child directories), so child
> directories are processed only after parent directory completes.
>
> The problem is that the initial thread dispatching in
> zfs_foreach_mountpoint() can be multi-threaded when it needs to be
> single-threaded, and this puts threads under race condition. This race
> appeared as mount/unmount issues on ZoL for ZoL having different
> timing regarding mount(2) execution due to fork(2)/exec(2) of mount(8).
> `zfs unmount -a` which expects proper mount order can't unmount if the
> mounts were reordered by the race condition.
>
> There are currently two known patterns of input list `handles` in
> `zfs_foreach_mountpoint(..,handles,..)` which cause the race condition.
>
> 1) #8833 case where input is `/a /a /a/b` after sorting.
> The problem is that libzfs_path_contains() can't correctly handle an
> input list with two same top level directories.
> There is a race between two POSIX threads A and B,
> * ThreadA for "/a" for test1 and "/a/b"
> * ThreadB for "/a" for test0/a
> and in case of #8833, ThreadA won the race. Two threads were created
> because "/a" wasn't considered as `"/a" contains "/a"`.
>
> 2) #8450 case where input is `/ /var/data /var/data/test` after sorting.
> The problem is that libzfs_path_contains() can't correctly handle an
> input list containing "/".
> There is a race between two POSIX threads A and B,
> * ThreadA for "/" and "/var/data/test"
> * ThreadB for "/var/data"
> and in case of #8450, ThreadA won the race. Two threads were created
> because "/var/data" wasn't considered as `"/" contains "/var/data"`.
> In other words, if there is (at least one) "/" in the input list,
> the initial thread dispatching must be single-threaded since every
> directory is a child of "/", meaning they all directly or indirectly
> depend on "/".
>
> In both cases, the first non_descendant_idx() call fails to correctly
> determine "path1-contains-path2", and as a result the initial thread
> dispatching creates another thread when it needs to be single-threaded.
> Fix a conditional in libzfs_path_contains() to consider above two.
>
> Reviewed-by: Brian Behlendorf <behlendorf1 at llnl.gov>
> Reviewed by: Sebastien Roy <sebastien.roy at delphix.com>
> Signed-off-by: Tomohiro Kusumi <kusumi.tomohiro at gmail.com>
>
> PR: 237517, 237397, 239243
> Submitted by: Matthew D. Fuller <fullermd at over-yonder.net> (by email)
>
> Modified:
> stable/11/cddl/contrib/opensolaris/lib/libzfs/common/libzfs_mount.c
> Directory Properties:
> stable/11/ (props changed)
>
> Modified: stable/11/cddl/contrib/opensolaris/lib/libzfs/common/libzfs_mount.c
> ==============================================================================
> --- stable/11/cddl/contrib/opensolaris/lib/libzfs/common/libzfs_mount.c Mon Jul 29 08:14:35 2019 (r350401)
> +++ stable/11/cddl/contrib/opensolaris/lib/libzfs/common/libzfs_mount.c Mon Jul 29 08:23:15 2019 (r350402)
> @@ -1281,12 +1281,14 @@ mountpoint_cmp(const void *arga, const void *argb)
> }
>
> /*
> - * Reutrn true if path2 is a child of path1
> + * Return true if path2 is a child of path1 or path2 equals path1 or
> + * path1 is "/" (path2 is always a child of "/").
> */
> static boolean_t
> libzfs_path_contains(const char *path1, const char *path2)
> {
> - return (strstr(path2, path1) == path2 && path2[strlen(path1)] == '/');
> + return (strcmp(path1, path2) == 0 || strcmp(path1, "/") == 0 ||
> + (strstr(path2, path1) == path2 && path2[strlen(path1)] == '/'));
> }
>
>
> _______________________________________________
> svn-src-all at freebsd.org mailing list
> https://lists.freebsd.org/mailman/listinfo/svn-src-all
> To unsubscribe, send any mail to "svn-src-all-unsubscribe at freebsd.org"
More information about the svn-src-all
mailing list