diff options
| 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/super.c | |
| parent | c77b52c0a137994ad796f44544c802b0b766e496 (diff) | |
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/super.c')
| -rw-r--r-- | fs/gfs2/super.c | 23 |
1 files changed, 0 insertions, 23 deletions
diff --git a/fs/gfs2/super.c b/fs/gfs2/super.c index ea312a94ce69..754ea2a137b4 100644 --- a/fs/gfs2/super.c +++ b/fs/gfs2/super.c @@ -165,7 +165,6 @@ int gfs2_make_fs_rw(struct gfs2_sbd *sdp) { struct gfs2_inode *ip = GFS2_I(sdp->sd_jdesc->jd_inode); struct gfs2_glock *j_gl = ip->i_gl; - struct gfs2_holder freeze_gh; struct gfs2_log_header_host head; int error; @@ -173,10 +172,6 @@ int gfs2_make_fs_rw(struct gfs2_sbd *sdp) if (error) return error; - error = gfs2_freeze_lock(sdp, &freeze_gh, 0); - if (error) - goto fail_threads; - j_gl->gl_ops->go_inval(j_gl, DIO_METADATA); if (gfs2_withdrawn(sdp)) { error = -EIO; @@ -203,13 +198,9 @@ int gfs2_make_fs_rw(struct gfs2_sbd *sdp) set_bit(SDF_JOURNAL_LIVE, &sdp->sd_flags); - gfs2_freeze_unlock(&freeze_gh); - return 0; fail: - gfs2_freeze_unlock(&freeze_gh); -fail_threads: if (sdp->sd_quotad_process) kthread_stop(sdp->sd_quotad_process); sdp->sd_quotad_process = NULL; @@ -607,21 +598,9 @@ out: int gfs2_make_fs_ro(struct gfs2_sbd *sdp) { - struct gfs2_holder freeze_gh; int error = 0; int log_write_allowed = test_bit(SDF_JOURNAL_LIVE, &sdp->sd_flags); - gfs2_holder_mark_uninitialized(&freeze_gh); - if (sdp->sd_freeze_gl && - !gfs2_glock_is_locked_by_me(sdp->sd_freeze_gl)) { - error = gfs2_freeze_lock(sdp, &freeze_gh, - log_write_allowed ? 0 : LM_FLAG_TRY); - if (error == GLR_TRYFAILED) - error = 0; - if (error && !gfs2_withdrawn(sdp)) - return error; - } - gfs2_flush_delete_work(sdp); if (!log_write_allowed && current == sdp->sd_quotad_process) fs_warn(sdp, "The quotad daemon is withdrawing.\n"); @@ -650,8 +629,6 @@ int gfs2_make_fs_ro(struct gfs2_sbd *sdp) atomic_read(&sdp->sd_reserving_log) == 0, HZ * 5); } - gfs2_freeze_unlock(&freeze_gh); - gfs2_quota_cleanup(sdp); if (!log_write_allowed) |