diff options
Diffstat (limited to 'fs/gfs2/glock.c')
| -rw-r--r-- | fs/gfs2/glock.c | 42 |
1 files changed, 38 insertions, 4 deletions
diff --git a/fs/gfs2/glock.c b/fs/gfs2/glock.c index 75d54ed7e54e..08073dcaf30e 100644 --- a/fs/gfs2/glock.c +++ b/fs/gfs2/glock.c @@ -479,12 +479,42 @@ find_first_strong_holder(struct gfs2_glock *gl) * Returns: 0 if instantiate was successful, 2 if type specific operation is * underway, or error. */ -static int gfs2_instantiate(struct gfs2_holder *gh) +int gfs2_instantiate(struct gfs2_holder *gh) { struct gfs2_glock *gl = gh->gh_gl; const struct gfs2_glock_operations *glops = gl->gl_ops; + int ret; + +again: + if (!test_bit(GLF_INSTANTIATE_NEEDED, &gl->gl_flags)) + return 0; - return glops->go_instantiate(gh); + /* + * Since we unlock the lockref lock, we set a flag to indicate + * instantiate is in progress. + */ + if (test_bit(GLF_INSTANTIATE_IN_PROG, &gl->gl_flags)) { + wait_on_bit(&gl->gl_flags, GLF_INSTANTIATE_IN_PROG, + TASK_UNINTERRUPTIBLE); + /* + * Here we just waited for a different instantiate to finish. + * But that may not have been successful, as when a process + * locks an inode glock _before_ it has an actual inode to + * instantiate into. So we check again. This process might + * have an inode to instantiate, so might be successful. + */ + goto again; + } + + set_bit(GLF_INSTANTIATE_IN_PROG, &gl->gl_flags); + + ret = glops->go_instantiate(gh); + if (!ret) + clear_bit(GLF_INSTANTIATE_NEEDED, &gl->gl_flags); + clear_bit(GLF_INSTANTIATE_IN_PROG, &gl->gl_flags); + smp_mb__after_atomic(); + wake_up_bit(&gl->gl_flags, GLF_INSTANTIATE_IN_PROG); + return ret; } /** @@ -526,7 +556,7 @@ restart: incompat_holders_demoted = true; first_gh = gh; } - if (gh->gh_list.prev == &gl->gl_holders && + if (test_bit(GLF_INSTANTIATE_NEEDED, &gl->gl_flags) && !(gh->gh_flags & GL_SKIP) && gl->gl_ops->go_instantiate) { lock_released = true; spin_unlock(&gl->gl_lockref.lock); @@ -1162,7 +1192,7 @@ int gfs2_glock_get(struct gfs2_sbd *sdp, u64 number, atomic_inc(&sdp->sd_glock_disposal); gl->gl_node.next = NULL; - gl->gl_flags = 0; + gl->gl_flags = glops->go_instantiate ? BIT(GLF_INSTANTIATE_NEEDED) : 0; gl->gl_name = name; lockdep_set_subclass(&gl->gl_lockref.lock, glops->go_subclass); gl->gl_lockref.count = 1; @@ -2326,6 +2356,10 @@ static const char *gflags2str(char *buf, const struct gfs2_glock *gl) *p++ = 'P'; if (test_bit(GLF_FREEING, gflags)) *p++ = 'x'; + if (test_bit(GLF_INSTANTIATE_NEEDED, gflags)) + *p++ = 'n'; + if (test_bit(GLF_INSTANTIATE_IN_PROG, gflags)) + *p++ = 'N'; *p = 0; return buf; } |