From: Darrick J. Wong <djwong@xxxxxxxxxx>
Implement FITRIM for the realtime device by pretending that it's
"space" immediately after the data device. We have to hold the
rtbitmap ILOCK while the discard operations are ongoing because there's
no busy extent tracking to prevent reallocations.
Signed-off-by: Darrick J. Wong <djwong@xxxxxxxxxx>
---
v2.1: hold the rtbitmap ilock while discarding to avoid corruption
---
fs/xfs/xfs_discard.c | 253 +++++++++++++++++++++++++++++++++++++++++++++++++-
fs/xfs/xfs_trace.h | 29 ++++++
2 files changed, 275 insertions(+), 7 deletions(-)
diff --git a/fs/xfs/xfs_discard.c b/fs/xfs/xfs_discard.c
index 25fe3b932b5a6..2c0aaa512852a 100644
--- a/fs/xfs/xfs_discard.c
+++ b/fs/xfs/xfs_discard.c
@@ -20,6 +20,7 @@
#include "xfs_log.h"
#include "xfs_ag.h"
#include "xfs_health.h"
+#include "xfs_rtbitmap.h"
/*
* Notes on an efficient, low latency fstrim algorithm
@@ -383,6 +384,218 @@ xfs_trim_extents(
}
+#ifdef CONFIG_XFS_RT
+struct xfs_trim_rtdev {
+ /* list of rt extents to free */
+ struct list_head extent_list;
+
+ /* pointer to count of blocks trimmed */
+ uint64_t *blocks_trimmed;
+
+ /* minimum length that caller allows us to trim */
+ xfs_rtblock_t minlen_fsb;
+
+ /* restart point for the rtbitmap walk */
+ xfs_rtxnum_t restart_rtx;
+
+ /* stopping point for the current rtbitmap walk */
+ xfs_rtxnum_t stop_rtx;
+};
+
+struct xfs_rtx_busy {
+ struct list_head list;
+ xfs_rtblock_t bno;
+ xfs_rtblock_t length;
+};
+
+static void
+xfs_discard_free_rtdev_extents(
+ struct xfs_trim_rtdev *tr)
+{
+ struct xfs_rtx_busy *busyp, *n;
+
+ list_for_each_entry_safe(busyp, n, &tr->extent_list, list) {
+ list_del_init(&busyp->list);
+ kfree(busyp);
+ }
+}
+
+/*
+ * Walk the discard list and issue discards on all the busy extents in the
+ * list. We plug and chain the bios so that we only need a single completion
+ * call to clear all the busy extents once the discards are complete.
+ */
+static int
+xfs_discard_rtdev_extents(
+ struct xfs_mount *mp,
+ struct xfs_trim_rtdev *tr)
+{
+ struct block_device *bdev = mp->m_rtdev_targp->bt_bdev;
+ struct xfs_rtx_busy *busyp;
+ struct bio *bio = NULL;
+ struct blk_plug plug;
+ xfs_rtblock_t start = NULLRTBLOCK, length = 0;
+ int error = 0;
+
+ blk_start_plug(&plug);
+ list_for_each_entry(busyp, &tr->extent_list, list) {
+ if (start == NULLRTBLOCK)
+ start = busyp->bno;
+ length += busyp->length;
+
+ trace_xfs_discard_rtextent(mp, busyp->bno, busyp->length);
+
+ error = __blkdev_issue_discard(bdev,
+ XFS_FSB_TO_BB(mp, busyp->bno),
+ XFS_FSB_TO_BB(mp, busyp->length),
+ GFP_NOFS, &bio);
+ if (error)
+ break;
+ }
+ xfs_discard_free_rtdev_extents(tr);
+
+ if (bio) {
+ error = submit_bio_wait(bio);
+ if (error == -EOPNOTSUPP)
+ error = 0;
+ if (error)
+ xfs_info(mp,
+ "discard failed for rtextent [0x%llx,%llu], error %d",
+ (unsigned long long)start,
+ (unsigned long long)length,
+ error);
+ bio_put(bio);
+ }
+ blk_finish_plug(&plug);
+
+ return error;
+}
+
+static int
+xfs_trim_gather_rtextent(
+ struct xfs_mount *mp,
+ struct xfs_trans *tp,
+ const struct xfs_rtalloc_rec *rec,
+ void *priv)
+{
+ struct xfs_trim_rtdev *tr = priv;
+ struct xfs_rtx_busy *busyp;
+ xfs_rtblock_t rbno, rlen;
+
+ if (rec->ar_startext > tr->stop_rtx) {
+ /*
+ * If we've scanned a large number of rtbitmap blocks, update
+ * the cursor to point at this extent so we restart the next
+ * batch from this extent.
+ */
+ tr->restart_rtx = rec->ar_startext;
+ return -ECANCELED;
+ }
+
+ rbno = xfs_rtx_to_rtb(mp, rec->ar_startext);
+ rlen = xfs_rtx_to_rtb(mp, rec->ar_extcount);
+
+ /* Ignore too small. */
+ if (rlen < tr->minlen_fsb) {
+ trace_xfs_discard_rttoosmall(mp, rbno, rlen);
+ return 0;
+ }
+
+ busyp = kzalloc(sizeof(struct xfs_rtx_busy), GFP_KERNEL);
+ if (!busyp)
+ return -ENOMEM;
+
+ busyp->bno = rbno;
+ busyp->length = rlen;
+ INIT_LIST_HEAD(&busyp->list);
+ list_add_tail(&busyp->list, &tr->extent_list);
+ *tr->blocks_trimmed += rlen;
+
+ tr->restart_rtx = rec->ar_startext + rec->ar_extcount;
+ return 0;
+}
+
+static int
+xfs_trim_rtdev_extents(
+ struct xfs_mount *mp,
+ xfs_daddr_t start,
+ xfs_daddr_t end,
+ xfs_daddr_t minlen,
+ uint64_t *blocks_trimmed)
+{
+ struct xfs_rtalloc_rec low = { };
+ struct xfs_rtalloc_rec high = { };
+ struct xfs_trim_rtdev tr = {
+ .blocks_trimmed = blocks_trimmed,
+ .minlen_fsb = XFS_BB_TO_FSB(mp, minlen),
+ };
+ struct xfs_trans *tp;
+ xfs_daddr_t rtdev_daddr;
+ int error;
+
+ INIT_LIST_HEAD(&tr.extent_list);
+
+ /* Shift the start and end downwards to match the rt device. */
+ rtdev_daddr = XFS_FSB_TO_BB(mp, mp->m_sb.sb_dblocks);
+ if (start > rtdev_daddr)
+ start -= rtdev_daddr;
+ else
+ start = 0;
+
+ if (end <= rtdev_daddr)
+ return 0;
+ end -= rtdev_daddr;
+
+ error = xfs_trans_alloc_empty(mp, &tp);
+ if (error)
+ return error;
+
+ if (end > XFS_FSB_TO_BB(mp, mp->m_sb.sb_rblocks) - 1)
+ end = XFS_FSB_TO_BB(mp, mp->m_sb.sb_rblocks) - 1;
+
+ /* Convert the rt blocks to rt extents */
+ low.ar_startext = xfs_rtb_to_rtxup(mp, XFS_BB_TO_FSB(mp, start));
+ high.ar_startext = xfs_rtb_to_rtx(mp, XFS_BB_TO_FSBT(mp, end));
+
+ /*
+ * Walk the free ranges between low and high. The query_range function
+ * trims the extents returned.
+ */
+ do {
+ tr.stop_rtx = low.ar_startext +
+ xfs_rtbitmap_rtx_per_rbmblock(mp);
+ xfs_rtbitmap_lock_shared(mp, XFS_RBMLOCK_BITMAP);
+ error = xfs_rtalloc_query_range(mp, tp, &low, &high,
+ xfs_trim_gather_rtextent, &tr);
+
+ if (error == -ECANCELED)
+ error = 0;
+ if (error) {
+ xfs_rtbitmap_unlock_shared(mp, XFS_RBMLOCK_BITMAP);
+ xfs_discard_free_rtdev_extents(&tr);
+ break;
+ }
+
+ if (list_empty(&tr.extent_list)) {
+ xfs_rtbitmap_unlock_shared(mp, XFS_RBMLOCK_BITMAP);
+ break;
+ }
+
+ error = xfs_discard_rtdev_extents(mp, &tr);
+ xfs_rtbitmap_unlock_shared(mp, XFS_RBMLOCK_BITMAP);
+ if (error)
+ break;
+
+ low.ar_startext = tr.restart_rtx;
+ } while (!xfs_trim_should_stop() && low.ar_startext <= high.ar_startext);
+
+ xfs_trans_cancel(tp);
+ return error;
+}
+#else
+# define xfs_trim_rtdev_extents(m,s,e,n,b) (-EOPNOTSUPP)
+#endif /* CONFIG_XFS_RT */
+
/*
* trim a range of the filesystem.
*
@@ -391,6 +604,9 @@ xfs_trim_extents(
* addressing. FSB addressing is sparse (AGNO|AGBNO), while the incoming format
* is a linear address range. Hence we need to use DADDR based conversions and
* comparisons for determining the correct offset and regions to trim.
+ *
+ * The realtime device is mapped into the FITRIM "address space" immediately
+ * after the data device.
*/
int
xfs_ioc_trim(
@@ -400,19 +616,28 @@ xfs_ioc_trim(
struct xfs_perag *pag;
unsigned int granularity =
bdev_discard_granularity(mp->m_ddev_targp->bt_bdev);
+ struct block_device *rt_bdev = NULL;
struct fstrim_range range;
- xfs_daddr_t start, end;
+ xfs_daddr_t start, end, ddev_end;
xfs_extlen_t minlen;
xfs_agnumber_t start_agno, end_agno;
xfs_agblock_t start_agbno, end_agbno;
+ xfs_rfsblock_t max_blocks;
uint64_t blocks_trimmed = 0;
int error, last_error = 0;
if (!capable(CAP_SYS_ADMIN))
return -EPERM;
- if (!bdev_max_discard_sectors(mp->m_ddev_targp->bt_bdev))
+ if (mp->m_rtdev_targp)
+ rt_bdev = mp->m_rtdev_targp->bt_bdev;
+ if (!bdev_max_discard_sectors(mp->m_ddev_targp->bt_bdev) &&
+ (!rt_bdev || !bdev_max_discard_sectors(rt_bdev)))
return -EOPNOTSUPP;
+ if (rt_bdev)
+ granularity = max(granularity,
+ bdev_discard_granularity(rt_bdev));
+
/*
* We haven't recovered the log, so we cannot use our bnobt-guided
* storage zapping commands.
@@ -433,19 +658,25 @@ xfs_ioc_trim(
* used by the fstrim application. In the end it really doesn't
* matter as trimming blocks is an advisory interface.
*/
- if (range.start >= XFS_FSB_TO_B(mp, mp->m_sb.sb_dblocks) ||
+ max_blocks = mp->m_sb.sb_dblocks + mp->m_sb.sb_rblocks;
+ if (range.start >= XFS_FSB_TO_B(mp, max_blocks) ||
range.minlen > XFS_FSB_TO_B(mp, mp->m_ag_max_usable) ||
range.len < mp->m_sb.sb_blocksize)
return -EINVAL;
start = BTOBB(range.start);
- end = min_t(xfs_daddr_t, start + BTOBBT(range.len),
- XFS_FSB_TO_BB(mp, mp->m_sb.sb_dblocks)) - 1;
+ end = start + BTOBBT(range.len) - 1;
+
+ if (!bdev_max_discard_sectors(mp->m_ddev_targp->bt_bdev))
+ goto rt_discard;
+
+ ddev_end = min_t(xfs_daddr_t, end,
+ XFS_FSB_TO_BB(mp, mp->m_sb.sb_dblocks) - 1);
start_agno = xfs_daddr_to_agno(mp, start);
start_agbno = xfs_daddr_to_agbno(mp, start);
- end_agno = xfs_daddr_to_agno(mp, end);
- end_agbno = xfs_daddr_to_agbno(mp, end);
+ end_agno = xfs_daddr_to_agno(mp, ddev_end);
+ end_agbno = xfs_daddr_to_agbno(mp, ddev_end);
for_each_perag_range(mp, start_agno, end_agno, pag) {
xfs_agblock_t agend = pag->block_count;
@@ -464,6 +695,14 @@ xfs_ioc_trim(
start_agbno = 0;
}
+rt_discard:
+ if (rt_bdev && bdev_max_discard_sectors(rt_bdev)) {
+ error = xfs_trim_rtdev_extents(mp, start, end, minlen,
+ &blocks_trimmed);
+ if (error)
+ last_error = error;
+ }
+
if (last_error)
return last_error;
diff --git a/fs/xfs/xfs_trace.h b/fs/xfs/xfs_trace.h
index 08964d2081c9d..747ccd4ec2a6e 100644
--- a/fs/xfs/xfs_trace.h
+++ b/fs/xfs/xfs_trace.h
@@ -2502,6 +2502,35 @@ DEFINE_DISCARD_EVENT(xfs_discard_toosmall);
DEFINE_DISCARD_EVENT(xfs_discard_exclude);
DEFINE_DISCARD_EVENT(xfs_discard_busy);
+DECLARE_EVENT_CLASS(xfs_rtdiscard_class,
+ TP_PROTO(struct xfs_mount *mp,
+ xfs_rtblock_t rtbno, xfs_rtblock_t len),
+ TP_ARGS(mp, rtbno, len),
+ TP_STRUCT__entry(
+ __field(dev_t, dev)
+ __field(xfs_rtblock_t, rtbno)
+ __field(xfs_rtblock_t, len)
+ ),
+ TP_fast_assign(
+ __entry->dev = mp->m_rtdev_targp->bt_dev;
+ __entry->rtbno = rtbno;
+ __entry->len = len;
+ ),
+ TP_printk("dev %d:%d rtbno 0x%llx rtbcount 0x%llx",
+ MAJOR(__entry->dev), MINOR(__entry->dev),
+ __entry->rtbno,
+ __entry->len)
+)
+
+#define DEFINE_RTDISCARD_EVENT(name) \
+DEFINE_EVENT(xfs_rtdiscard_class, name, \
+ TP_PROTO(struct xfs_mount *mp, \
+ xfs_rtblock_t rtbno, xfs_rtblock_t len), \
+ TP_ARGS(mp, rtbno, len))
+DEFINE_RTDISCARD_EVENT(xfs_discard_rtextent);
+DEFINE_RTDISCARD_EVENT(xfs_discard_rttoosmall);
+DEFINE_RTDISCARD_EVENT(xfs_discard_rtrelax);
+
DECLARE_EVENT_CLASS(xfs_btree_cur_class,
TP_PROTO(struct xfs_btree_cur *cur, int level, struct xfs_buf *bp),
TP_ARGS(cur, level, bp),
