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authorMikulas Patocka <mpatocka@redhat.com>2023-06-26 16:46:00 +0200
committerMike Snitzer <snitzer@kernel.org>2023-06-27 16:02:18 -0400
commitda8b4fc1f63a01a0eca9338ae338b804c437b51f (patch)
treed4b671cee1d6c6e28a52a760d6757d9deaa1319c /drivers/md
parent6d50eb4725934fd22f5eeccb401000687c790fd0 (diff)
downloadlwn-da8b4fc1f63a01a0eca9338ae338b804c437b51f.tar.gz
lwn-da8b4fc1f63a01a0eca9338ae338b804c437b51f.zip
dm integrity: only allocate recalculate buffer when needed
dm-integrity preallocated 8MiB buffer for recalculating in the constructor and freed it in the destructor. This wastes memory when the user has many dm-integrity devices. Fix dm-integrity so that the buffer is only allocated when recalculation is in progress; allocate the buffer at the beginning of integrity_recalc() and free it at the end. Note that integrity_recalc() doesn't hold any locks when allocating the buffer, so it shouldn't cause low-memory deadlock. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@kernel.org>
Diffstat (limited to 'drivers/md')
-rw-r--r--drivers/md/dm-integrity.c52
1 files changed, 26 insertions, 26 deletions
diff --git a/drivers/md/dm-integrity.c b/drivers/md/dm-integrity.c
index 0a910bb8db17..16d1aa263066 100644
--- a/drivers/md/dm-integrity.c
+++ b/drivers/md/dm-integrity.c
@@ -251,8 +251,6 @@ struct dm_integrity_c {
struct workqueue_struct *recalc_wq;
struct work_struct recalc_work;
- u8 *recalc_buffer;
- u8 *recalc_tags;
struct bio_list flush_bio_list;
@@ -2646,6 +2644,9 @@ static void recalc_write_super(struct dm_integrity_c *ic)
static void integrity_recalc(struct work_struct *w)
{
struct dm_integrity_c *ic = container_of(w, struct dm_integrity_c, recalc_work);
+ size_t recalc_tags_size;
+ u8 *recalc_buffer = NULL;
+ u8 *recalc_tags = NULL;
struct dm_integrity_range range;
struct dm_io_request io_req;
struct dm_io_region io_loc;
@@ -2658,6 +2659,20 @@ static void integrity_recalc(struct work_struct *w)
int r;
unsigned int super_counter = 0;
+ recalc_buffer = __vmalloc(RECALC_SECTORS << SECTOR_SHIFT, GFP_NOIO);
+ if (!recalc_buffer) {
+ DMCRIT("out of memory for recalculate buffer - recalculation disabled");
+ goto free_ret;
+ }
+ recalc_tags_size = (RECALC_SECTORS >> ic->sb->log2_sectors_per_block) * ic->tag_size;
+ if (crypto_shash_digestsize(ic->internal_hash) > ic->tag_size)
+ recalc_tags_size += crypto_shash_digestsize(ic->internal_hash) - ic->tag_size;
+ recalc_tags = kvmalloc(recalc_tags_size, GFP_NOIO);
+ if (!recalc_tags) {
+ DMCRIT("out of memory for recalculate buffer - recalculation disabled");
+ goto free_ret;
+ }
+
DEBUG_print("start recalculation... (position %llx)\n", le64_to_cpu(ic->sb->recalc_sector));
spin_lock_irq(&ic->endio_wait.lock);
@@ -2720,7 +2735,7 @@ next_chunk:
io_req.bi_opf = REQ_OP_READ;
io_req.mem.type = DM_IO_VMA;
- io_req.mem.ptr.addr = ic->recalc_buffer;
+ io_req.mem.ptr.addr = recalc_buffer;
io_req.notify.fn = NULL;
io_req.client = ic->io;
io_loc.bdev = ic->dev->bdev;
@@ -2733,15 +2748,15 @@ next_chunk:
goto err;
}
- t = ic->recalc_tags;
+ t = recalc_tags;
for (i = 0; i < n_sectors; i += ic->sectors_per_block) {
- integrity_sector_checksum(ic, logical_sector + i, ic->recalc_buffer + (i << SECTOR_SHIFT), t);
+ integrity_sector_checksum(ic, logical_sector + i, recalc_buffer + (i << SECTOR_SHIFT), t);
t += ic->tag_size;
}
metadata_block = get_metadata_sector_and_offset(ic, area, offset, &metadata_offset);
- r = dm_integrity_rw_tag(ic, ic->recalc_tags, &metadata_block, &metadata_offset, t - ic->recalc_tags, TAG_WRITE);
+ r = dm_integrity_rw_tag(ic, recalc_tags, &metadata_block, &metadata_offset, t - recalc_tags, TAG_WRITE);
if (unlikely(r)) {
dm_integrity_io_error(ic, "writing tags", r);
goto err;
@@ -2769,12 +2784,16 @@ advance_and_next:
err:
remove_range(ic, &range);
- return;
+ goto free_ret;
unlock_ret:
spin_unlock_irq(&ic->endio_wait.lock);
recalc_write_super(ic);
+
+free_ret:
+ vfree(recalc_buffer);
+ kvfree(recalc_tags);
}
static void bitmap_block_work(struct work_struct *w)
@@ -4439,8 +4458,6 @@ try_smaller_buffer:
}
if (ic->internal_hash) {
- size_t recalc_tags_size;
-
ic->recalc_wq = alloc_workqueue("dm-integrity-recalc", WQ_MEM_RECLAIM, 1);
if (!ic->recalc_wq) {
ti->error = "Cannot allocate workqueue";
@@ -4448,21 +4465,6 @@ try_smaller_buffer:
goto bad;
}
INIT_WORK(&ic->recalc_work, integrity_recalc);
- ic->recalc_buffer = vmalloc(RECALC_SECTORS << SECTOR_SHIFT);
- if (!ic->recalc_buffer) {
- ti->error = "Cannot allocate buffer for recalculating";
- r = -ENOMEM;
- goto bad;
- }
- recalc_tags_size = (RECALC_SECTORS >> ic->sb->log2_sectors_per_block) * ic->tag_size;
- if (crypto_shash_digestsize(ic->internal_hash) > ic->tag_size)
- recalc_tags_size += crypto_shash_digestsize(ic->internal_hash) - ic->tag_size;
- ic->recalc_tags = kvmalloc(recalc_tags_size, GFP_KERNEL);
- if (!ic->recalc_tags) {
- ti->error = "Cannot allocate tags for recalculating";
- r = -ENOMEM;
- goto bad;
- }
} else {
if (ic->sb->flags & cpu_to_le32(SB_FLAG_RECALCULATING)) {
ti->error = "Recalculate can only be specified with internal_hash";
@@ -4606,8 +4608,6 @@ static void dm_integrity_dtr(struct dm_target *ti)
destroy_workqueue(ic->writer_wq);
if (ic->recalc_wq)
destroy_workqueue(ic->recalc_wq);
- vfree(ic->recalc_buffer);
- kvfree(ic->recalc_tags);
kvfree(ic->bbs);
if (ic->bufio)
dm_bufio_client_destroy(ic->bufio);