Revert "Fix stack traverse_visitbp()"

This abomination is no longer required because the zio's issued
during this recursive call path will now be handled asynchronously
by the taskq thread pool.

This reverts commit 6656bf5621.
This commit is contained in:
Brian Behlendorf 2011-05-25 16:09:57 -07:00
parent 2fac4c2a74
commit c7f8f831a4

View File

@ -59,31 +59,6 @@ typedef struct traverse_data {
void *td_arg;
} traverse_data_t;
typedef struct traverse_visitbp_data {
/* Function arguments */
traverse_data_t *tv_td;
const dnode_phys_t *tv_dnp;
arc_buf_t *tv_pbuf;
blkptr_t *tv_bp;
const zbookmark_t *tv_zb;
/* Local variables */
prefetch_data_t *tv_pd;
zbookmark_t tv_czb;
arc_buf_t *tv_buf;
boolean_t tv_hard;
objset_phys_t *tv_osp;
dnode_phys_t *tv_ldnp;
blkptr_t *tv_cbp;
uint32_t tv_flags;
int tv_err;
int tv_lasterr;
int tv_i;
int tv_epb;
int tv_depth;
} traverse_visitbp_data_t;
static inline int traverse_visitbp(traverse_data_t *td, const
dnode_phys_t *dnp, arc_buf_t *pbuf, blkptr_t *bp, const zbookmark_t *zb);
static int traverse_dnode(traverse_data_t *td, const dnode_phys_t *dnp,
arc_buf_t *buf, uint64_t objset, uint64_t object);
@ -153,191 +128,137 @@ traverse_zil(traverse_data_t *td, zil_header_t *zh)
zil_free(zilog);
}
#define TRAVERSE_VISITBP_MAX_DEPTH 20
static void
__traverse_visitbp_init(traverse_visitbp_data_t *tv,
traverse_data_t *td, const dnode_phys_t *dnp,
arc_buf_t *pbuf, blkptr_t *bp, const zbookmark_t *zb, int depth)
{
tv->tv_td = td;
tv->tv_dnp = dnp;
tv->tv_pbuf = pbuf;
tv->tv_bp = bp;
tv->tv_zb = zb;
tv->tv_err = 0;
tv->tv_lasterr = 0;
tv->tv_buf = NULL;
tv->tv_pd = td->td_pfd;
tv->tv_hard = td->td_flags & TRAVERSE_HARD;
tv->tv_flags = ARC_WAIT;
tv->tv_depth = depth;
}
static noinline int
__traverse_visitbp(traverse_visitbp_data_t *tv)
{
ASSERT3S(tv->tv_depth, <, TRAVERSE_VISITBP_MAX_DEPTH);
if (tv->tv_bp->blk_birth == 0) {
tv->tv_err = tv->tv_td->td_func(tv->tv_td->td_spa, NULL, NULL,
tv->tv_pbuf, tv->tv_zb, tv->tv_dnp, tv->tv_td->td_arg);
return (tv->tv_err);
}
if (tv->tv_bp->blk_birth <= tv->tv_td->td_min_txg)
return (0);
if (tv->tv_pd && !tv->tv_pd->pd_exited &&
((tv->tv_pd->pd_flags & TRAVERSE_PREFETCH_DATA) ||
BP_GET_TYPE(tv->tv_bp) == DMU_OT_DNODE ||
BP_GET_LEVEL(tv->tv_bp) > 0)) {
mutex_enter(&tv->tv_pd->pd_mtx);
ASSERT(tv->tv_pd->pd_blks_fetched >= 0);
while (tv->tv_pd->pd_blks_fetched == 0 && !tv->tv_pd->pd_exited)
cv_wait(&tv->tv_pd->pd_cv, &tv->tv_pd->pd_mtx);
tv->tv_pd->pd_blks_fetched--;
cv_broadcast(&tv->tv_pd->pd_cv);
mutex_exit(&tv->tv_pd->pd_mtx);
}
if (tv->tv_td->td_flags & TRAVERSE_PRE) {
tv->tv_err = tv->tv_td->td_func(tv->tv_td->td_spa, NULL,
tv->tv_bp, tv->tv_pbuf, tv->tv_zb, tv->tv_dnp,
tv->tv_td->td_arg);
if (tv->tv_err == TRAVERSE_VISIT_NO_CHILDREN)
return (0);
if (tv->tv_err)
return (tv->tv_err);
}
if (BP_GET_LEVEL(tv->tv_bp) > 0) {
tv->tv_epb = BP_GET_LSIZE(tv->tv_bp) >> SPA_BLKPTRSHIFT;
tv->tv_err = dsl_read(NULL, tv->tv_td->td_spa, tv->tv_bp,
tv->tv_pbuf, arc_getbuf_func, &tv->tv_buf,
ZIO_PRIORITY_ASYNC_READ, ZIO_FLAG_CANFAIL,
&tv->tv_flags, tv->tv_zb);
if (tv->tv_err)
return (tv->tv_err);
/* recursively visitbp() blocks below this */
tv->tv_cbp = tv->tv_buf->b_data;
for (tv->tv_i = 0; tv->tv_i < tv->tv_epb;
tv->tv_i++, tv->tv_cbp++) {
SET_BOOKMARK(&tv->tv_czb, tv->tv_zb->zb_objset,
tv->tv_zb->zb_object, tv->tv_zb->zb_level - 1,
tv->tv_zb->zb_blkid * tv->tv_epb + tv->tv_i);
__traverse_visitbp_init(tv + 1, tv->tv_td,
tv->tv_dnp, tv->tv_buf, tv->tv_cbp,
&tv->tv_czb, tv->tv_depth + 1);
tv->tv_err = __traverse_visitbp(tv + 1);
if (tv->tv_err) {
if (!tv->tv_hard)
break;
tv->tv_lasterr = tv->tv_err;
}
}
} else if (BP_GET_TYPE(tv->tv_bp) == DMU_OT_DNODE) {
tv->tv_epb = BP_GET_LSIZE(tv->tv_bp) >> DNODE_SHIFT;
tv->tv_err = dsl_read(NULL, tv->tv_td->td_spa, tv->tv_bp,
tv->tv_pbuf, arc_getbuf_func, &tv->tv_buf,
ZIO_PRIORITY_ASYNC_READ, ZIO_FLAG_CANFAIL,
&tv->tv_flags, tv->tv_zb);
if (tv->tv_err)
return (tv->tv_err);
/* recursively visitbp() blocks below this */
tv->tv_dnp = tv->tv_buf->b_data;
for (tv->tv_i = 0; tv->tv_i < tv->tv_epb;
tv->tv_i++, tv->tv_dnp++) {
tv->tv_err = traverse_dnode(tv->tv_td, tv->tv_dnp,
tv->tv_buf, tv->tv_zb->zb_objset,
tv->tv_zb->zb_blkid * tv->tv_epb + tv->tv_i);
if (tv->tv_err) {
if (!tv->tv_hard)
break;
tv->tv_lasterr = tv->tv_err;
}
}
} else if (BP_GET_TYPE(tv->tv_bp) == DMU_OT_OBJSET) {
tv->tv_err = dsl_read_nolock(NULL, tv->tv_td->td_spa,
tv->tv_bp, arc_getbuf_func, &tv->tv_buf,
ZIO_PRIORITY_ASYNC_READ, ZIO_FLAG_CANFAIL,
&tv->tv_flags, tv->tv_zb);
if (tv->tv_err)
return (tv->tv_err);
tv->tv_osp = tv->tv_buf->b_data;
tv->tv_ldnp = &tv->tv_osp->os_meta_dnode;
tv->tv_err = traverse_dnode(tv->tv_td, tv->tv_ldnp, tv->tv_buf,
tv->tv_zb->zb_objset, DMU_META_DNODE_OBJECT);
if (tv->tv_err && tv->tv_hard) {
tv->tv_lasterr = tv->tv_err;
tv->tv_err = 0;
}
if (tv->tv_err == 0 &&
arc_buf_size(tv->tv_buf) >= sizeof (objset_phys_t)) {
tv->tv_ldnp = &tv->tv_osp->os_userused_dnode;
tv->tv_err = traverse_dnode(tv->tv_td, tv->tv_ldnp,
tv->tv_buf, tv->tv_zb->zb_objset,
DMU_USERUSED_OBJECT);
}
if (tv->tv_err && tv->tv_hard) {
tv->tv_lasterr = tv->tv_err;
tv->tv_err = 0;
}
if (tv->tv_err == 0 &&
arc_buf_size(tv->tv_buf) >= sizeof (objset_phys_t)) {
tv->tv_ldnp = &tv->tv_osp->os_groupused_dnode;
tv->tv_err = traverse_dnode(tv->tv_td, tv->tv_ldnp,
tv->tv_buf, tv->tv_zb->zb_objset,
DMU_GROUPUSED_OBJECT);
}
}
if (tv->tv_buf)
(void) arc_buf_remove_ref(tv->tv_buf, &tv->tv_buf);
if (tv->tv_err == 0 && tv->tv_lasterr == 0 &&
(tv->tv_td->td_flags & TRAVERSE_POST)) {
tv->tv_err = tv->tv_td->td_func(tv->tv_td->td_spa, NULL,
tv->tv_bp, tv->tv_pbuf, tv->tv_zb, tv->tv_dnp,
tv->tv_td->td_arg);
}
return (tv->tv_err != 0 ? tv->tv_err : tv->tv_lasterr);
}
/*
* Due to limited stack space recursive functions are frowned upon in
* the Linux kernel. However, they often are the most elegant solution
* to a problem. The following code preserves the recursive function
* traverse_visitbp() but moves the local variables AND function
* arguments to the heap to minimize the stack frame size. Enough
* space is initially allocated on the stack for 16 levels of recursion.
* This change does ugly-up-the-code but it reduces the worst case
* usage from roughly 2496 bytes to 576 bytes on x86_64 archs.
*/
static int
traverse_visitbp(traverse_data_t *td, const dnode_phys_t *dnp,
arc_buf_t *pbuf, blkptr_t *bp, const zbookmark_t *zb)
{
traverse_visitbp_data_t *tv;
int error;
zbookmark_t czb;
int err = 0, lasterr = 0;
arc_buf_t *buf = NULL;
prefetch_data_t *pd = td->td_pfd;
boolean_t hard = td->td_flags & TRAVERSE_HARD;
tv = kmem_zalloc(sizeof(traverse_visitbp_data_t) *
TRAVERSE_VISITBP_MAX_DEPTH, KM_SLEEP);
__traverse_visitbp_init(tv, td, dnp, pbuf, bp, zb, 0);
if (bp->blk_birth == 0) {
err = td->td_func(td->td_spa, NULL, NULL, pbuf, zb, dnp,
td->td_arg);
return (err);
}
error = __traverse_visitbp(tv);
if (bp->blk_birth <= td->td_min_txg)
return (0);
kmem_free(tv, sizeof(traverse_visitbp_data_t) *
TRAVERSE_VISITBP_MAX_DEPTH);
if (pd && !pd->pd_exited &&
((pd->pd_flags & TRAVERSE_PREFETCH_DATA) ||
BP_GET_TYPE(bp) == DMU_OT_DNODE || BP_GET_LEVEL(bp) > 0)) {
mutex_enter(&pd->pd_mtx);
ASSERT(pd->pd_blks_fetched >= 0);
while (pd->pd_blks_fetched == 0 && !pd->pd_exited)
cv_wait(&pd->pd_cv, &pd->pd_mtx);
pd->pd_blks_fetched--;
cv_broadcast(&pd->pd_cv);
mutex_exit(&pd->pd_mtx);
}
return (error);
if (td->td_flags & TRAVERSE_PRE) {
err = td->td_func(td->td_spa, NULL, bp, pbuf, zb, dnp,
td->td_arg);
if (err == TRAVERSE_VISIT_NO_CHILDREN)
return (0);
if (err)
return (err);
}
if (BP_GET_LEVEL(bp) > 0) {
uint32_t flags = ARC_WAIT;
int i;
blkptr_t *cbp;
int epb = BP_GET_LSIZE(bp) >> SPA_BLKPTRSHIFT;
err = dsl_read(NULL, td->td_spa, bp, pbuf,
arc_getbuf_func, &buf,
ZIO_PRIORITY_ASYNC_READ, ZIO_FLAG_CANFAIL, &flags, zb);
if (err)
return (err);
/* recursively visitbp() blocks below this */
cbp = buf->b_data;
for (i = 0; i < epb; i++, cbp++) {
SET_BOOKMARK(&czb, zb->zb_objset, zb->zb_object,
zb->zb_level - 1,
zb->zb_blkid * epb + i);
err = traverse_visitbp(td, dnp, buf, cbp, &czb);
if (err) {
if (!hard)
break;
lasterr = err;
}
}
} else if (BP_GET_TYPE(bp) == DMU_OT_DNODE) {
uint32_t flags = ARC_WAIT;
int i;
int epb = BP_GET_LSIZE(bp) >> DNODE_SHIFT;
err = dsl_read(NULL, td->td_spa, bp, pbuf,
arc_getbuf_func, &buf,
ZIO_PRIORITY_ASYNC_READ, ZIO_FLAG_CANFAIL, &flags, zb);
if (err)
return (err);
/* recursively visitbp() blocks below this */
dnp = buf->b_data;
for (i = 0; i < epb; i++, dnp++) {
err = traverse_dnode(td, dnp, buf, zb->zb_objset,
zb->zb_blkid * epb + i);
if (err) {
if (!hard)
break;
lasterr = err;
}
}
} else if (BP_GET_TYPE(bp) == DMU_OT_OBJSET) {
uint32_t flags = ARC_WAIT;
objset_phys_t *osp;
dnode_phys_t *dnp;
err = dsl_read_nolock(NULL, td->td_spa, bp,
arc_getbuf_func, &buf,
ZIO_PRIORITY_ASYNC_READ, ZIO_FLAG_CANFAIL, &flags, zb);
if (err)
return (err);
osp = buf->b_data;
dnp = &osp->os_meta_dnode;
err = traverse_dnode(td, dnp, buf, zb->zb_objset,
DMU_META_DNODE_OBJECT);
if (err && hard) {
lasterr = err;
err = 0;
}
if (err == 0 && arc_buf_size(buf) >= sizeof (objset_phys_t)) {
dnp = &osp->os_userused_dnode;
err = traverse_dnode(td, dnp, buf, zb->zb_objset,
DMU_USERUSED_OBJECT);
}
if (err && hard) {
lasterr = err;
err = 0;
}
if (err == 0 && arc_buf_size(buf) >= sizeof (objset_phys_t)) {
dnp = &osp->os_groupused_dnode;
err = traverse_dnode(td, dnp, buf, zb->zb_objset,
DMU_GROUPUSED_OBJECT);
}
}
if (buf)
(void) arc_buf_remove_ref(buf, &buf);
if (err == 0 && lasterr == 0 && (td->td_flags & TRAVERSE_POST)) {
err = td->td_func(td->td_spa, NULL, bp, pbuf, zb, dnp,
td->td_arg);
}
return (err != 0 ? err : lasterr);
}
static int