xfs: don't block the log commit handler for discards

Instead we submit the discard requests and use another workqueue to
release the extents from the extent busy list.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
This commit is contained in:
Christoph Hellwig 2017-02-07 14:07:58 -08:00 committed by Darrick J. Wong
parent 4669412981
commit 4560e78f40
7 changed files with 88 additions and 38 deletions

View File

@ -208,32 +208,3 @@ xfs_ioc_trim(
return -EFAULT;
return 0;
}
int
xfs_discard_extents(
struct xfs_mount *mp,
struct list_head *list)
{
struct xfs_extent_busy *busyp;
int error = 0;
list_for_each_entry(busyp, list, list) {
trace_xfs_discard_extent(mp, busyp->agno, busyp->bno,
busyp->length);
error = blkdev_issue_discard(mp->m_ddev_targp->bt_bdev,
XFS_AGB_TO_DADDR(mp, busyp->agno, busyp->bno),
XFS_FSB_TO_BB(mp, busyp->length),
GFP_NOFS, 0);
if (error && error != -EOPNOTSUPP) {
xfs_info(mp,
"discard failed for extent [0x%llx,%u], error %d",
(unsigned long long)busyp->bno,
busyp->length,
error);
return error;
}
}
return 0;
}

View File

@ -5,6 +5,5 @@ struct fstrim_range;
struct list_head;
extern int xfs_ioc_trim(struct xfs_mount *, struct fstrim_range __user *);
extern int xfs_discard_extents(struct xfs_mount *, struct list_head *);
#endif /* XFS_DISCARD_H */

View File

@ -30,6 +30,9 @@
#include "xfs_trans_priv.h"
#include "xfs_log.h"
#include "xfs_log_priv.h"
#include "xfs_trace.h"
struct workqueue_struct *xfs_discard_wq;
/*
* Allocate a new ticket. Failing to get a new ticket makes it really hard to
@ -491,6 +494,75 @@ xlog_cil_free_logvec(
}
}
static void
xlog_discard_endio_work(
struct work_struct *work)
{
struct xfs_cil_ctx *ctx =
container_of(work, struct xfs_cil_ctx, discard_endio_work);
struct xfs_mount *mp = ctx->cil->xc_log->l_mp;
xfs_extent_busy_clear(mp, &ctx->busy_extents, false);
kmem_free(ctx);
}
/*
* Queue up the actual completion to a thread to avoid IRQ-safe locking for
* pagb_lock. Note that we need a unbounded workqueue, otherwise we might
* get the execution delayed up to 30 seconds for weird reasons.
*/
static void
xlog_discard_endio(
struct bio *bio)
{
struct xfs_cil_ctx *ctx = bio->bi_private;
INIT_WORK(&ctx->discard_endio_work, xlog_discard_endio_work);
queue_work(xfs_discard_wq, &ctx->discard_endio_work);
}
static void
xlog_discard_busy_extents(
struct xfs_mount *mp,
struct xfs_cil_ctx *ctx)
{
struct list_head *list = &ctx->busy_extents;
struct xfs_extent_busy *busyp;
struct bio *bio = NULL;
struct blk_plug plug;
int error = 0;
ASSERT(mp->m_flags & XFS_MOUNT_DISCARD);
blk_start_plug(&plug);
list_for_each_entry(busyp, list, list) {
trace_xfs_discard_extent(mp, busyp->agno, busyp->bno,
busyp->length);
error = __blkdev_issue_discard(mp->m_ddev_targp->bt_bdev,
XFS_AGB_TO_DADDR(mp, busyp->agno, busyp->bno),
XFS_FSB_TO_BB(mp, busyp->length),
GFP_NOFS, 0, &bio);
if (error && error != -EOPNOTSUPP) {
xfs_info(mp,
"discard failed for extent [0x%llx,%u], error %d",
(unsigned long long)busyp->bno,
busyp->length,
error);
break;
}
}
if (bio) {
bio->bi_private = ctx;
bio->bi_end_io = xlog_discard_endio;
submit_bio(bio);
} else {
xlog_discard_endio_work(&ctx->discard_endio_work);
}
blk_finish_plug(&plug);
}
/*
* Mark all items committed and clear busy extents. We free the log vector
* chains in a separate pass so that we unpin the log items as quickly as
@ -525,14 +597,10 @@ xlog_cil_committed(
xlog_cil_free_logvec(ctx->lv_chain);
if (!list_empty(&ctx->busy_extents)) {
ASSERT(mp->m_flags & XFS_MOUNT_DISCARD);
xfs_discard_extents(mp, &ctx->busy_extents);
xfs_extent_busy_clear(mp, &ctx->busy_extents, false);
}
kmem_free(ctx);
if (!list_empty(&ctx->busy_extents))
xlog_discard_busy_extents(mp, ctx);
else
kmem_free(ctx);
}
/*

View File

@ -257,6 +257,7 @@ struct xfs_cil_ctx {
struct xfs_log_vec *lv_chain; /* logvecs being pushed */
struct xfs_log_callback log_cb; /* completion callback hook. */
struct list_head committing; /* ctx committing list */
struct work_struct discard_endio_work;
};
/*

View File

@ -1085,6 +1085,7 @@ xfs_unmountfs(
* any discard operation.
*/
xfs_extent_busy_wait_all(mp);
flush_workqueue(xfs_discard_wq);
/*
* We now need to tell the world we are unmounting. This will allow

View File

@ -1956,12 +1956,20 @@ xfs_init_workqueues(void)
if (!xfs_alloc_wq)
return -ENOMEM;
xfs_discard_wq = alloc_workqueue("xfsdiscard", WQ_UNBOUND, 0);
if (!xfs_discard_wq)
goto out_free_alloc_wq;
return 0;
out_free_alloc_wq:
destroy_workqueue(xfs_alloc_wq);
return -ENOMEM;
}
STATIC void
xfs_destroy_workqueues(void)
{
destroy_workqueue(xfs_discard_wq);
destroy_workqueue(xfs_alloc_wq);
}

View File

@ -73,6 +73,8 @@ extern const struct quotactl_ops xfs_quotactl_operations;
extern void xfs_reinit_percpu_counters(struct xfs_mount *mp);
extern struct workqueue_struct *xfs_discard_wq;
#define XFS_M(sb) ((struct xfs_mount *)((sb)->s_fs_info))
#endif /* __XFS_SUPER_H__ */