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.
This patch changes dm-integrity so that it allocates the buffer in the
begining of the function integrity_recalc and free it in the end - so,
the buffer is only allocated when recalculation is in progress.
Note that the function 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@xxxxxxxxxx>
---
drivers/md/dm-integrity.c | 52 +++++++++++++++++++++++-----------------------
1 file changed, 26 insertions(+), 26 deletions(-)
Index: linux-2.6/drivers/md/dm-integrity.c
===================================================================
--- linux-2.6.orig/drivers/md/dm-integrity.c
+++ linux-2.6/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;
@@ -2661,6 +2659,9 @@ static void recalc_write_super(struct dm
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;
@@ -2673,6 +2674,20 @@ static void integrity_recalc(struct work
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);
@@ -2735,7 +2750,7 @@ 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;
@@ -2748,15 +2763,15 @@ 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;
@@ -2784,12 +2799,16 @@ 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)
@@ -4454,8 +4473,6 @@ 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";
@@ -4463,21 +4480,6 @@ 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";
@@ -4621,8 +4623,6 @@ static void dm_integrity_dtr(struct dm_t
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);
--
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