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| author | Bob Peterson <rpeterso@redhat.com> | 2020-12-22 14:43:28 -0600 |
|---|---|---|
| committer | Andreas Gruenbacher <agruenba@redhat.com> | 2020-12-23 00:54:21 +0100 |
| commit | 96b1454f2e8ede4c619fde405a1bb4e9ba8d218e (patch) | |
| tree | ec254d75a0d52a626cf0b2da1eb769d381566275 /fs/gfs2/util.c | |
| parent | c77b52c0a137994ad796f44544c802b0b766e496 (diff) | |
| download | linux-96b1454f2e8ede4c619fde405a1bb4e9ba8d218e.tar.gz linux-96b1454f2e8ede4c619fde405a1bb4e9ba8d218e.tar.bz2 linux-96b1454f2e8ede4c619fde405a1bb4e9ba8d218e.zip | |
gfs2: move freeze glock outside the make_fs_rw and _ro functions
Before this patch, sister functions gfs2_make_fs_rw and gfs2_make_fs_ro locked
(held) the freeze glock by calling gfs2_freeze_lock and gfs2_freeze_unlock.
The problem is, not all the callers of gfs2_make_fs_ro should be doing this.
The three callers of gfs2_make_fs_ro are: remount (gfs2_reconfigure),
signal_our_withdraw, and unmount (gfs2_put_super). But when unmounting the
file system we can get into the following circular lock dependency:
deactivate_super
down_write(&s->s_umount); <-------------------------------------- s_umount
deactivate_locked_super
gfs2_kill_sb
kill_block_super
generic_shutdown_super
gfs2_put_super
gfs2_make_fs_ro
gfs2_glock_nq_init sd_freeze_gl
freeze_go_sync
if (freeze glock in SH)
freeze_super (vfs)
down_write(&sb->s_umount); <------- s_umount
This patch moves the hold of the freeze glock outside the two sister rw/ro
functions to their callers, but it doesn't request the glock from
gfs2_put_super, thus eliminating the circular dependency.
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Diffstat (limited to 'fs/gfs2/util.c')
| -rw-r--r-- | fs/gfs2/util.c | 18 |
1 files changed, 16 insertions, 2 deletions
diff --git a/fs/gfs2/util.c b/fs/gfs2/util.c index a115c441e2a1..97b1bdc76871 100644 --- a/fs/gfs2/util.c +++ b/fs/gfs2/util.c @@ -122,6 +122,7 @@ static void signal_our_withdraw(struct gfs2_sbd *sdp) struct inode *inode = sdp->sd_jdesc->jd_inode; struct gfs2_inode *ip = GFS2_I(inode); u64 no_formal_ino = ip->i_no_formal_ino; + int log_write_allowed = test_bit(SDF_JOURNAL_LIVE, &sdp->sd_flags); int ret = 0; int tries; @@ -142,8 +143,21 @@ static void signal_our_withdraw(struct gfs2_sbd *sdp) * therefore we need to clear SDF_JOURNAL_LIVE manually. */ clear_bit(SDF_JOURNAL_LIVE, &sdp->sd_flags); - if (!sb_rdonly(sdp->sd_vfs)) - ret = gfs2_make_fs_ro(sdp); + if (!sb_rdonly(sdp->sd_vfs)) { + struct gfs2_holder freeze_gh; + + gfs2_holder_mark_uninitialized(&freeze_gh); + if (sdp->sd_freeze_gl && + !gfs2_glock_is_locked_by_me(sdp->sd_freeze_gl)) { + ret = gfs2_freeze_lock(sdp, &freeze_gh, + log_write_allowed ? 0 : LM_FLAG_TRY); + if (ret == GLR_TRYFAILED) + ret = 0; + } + if (!ret) + ret = gfs2_make_fs_ro(sdp); + gfs2_freeze_unlock(&freeze_gh); + } if (sdp->sd_lockstruct.ls_ops->lm_lock == NULL) { /* lock_nolock */ if (!ret) |