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Diffstat (limited to 'fs/btrfs/scrub.c')
-rw-r--r--fs/btrfs/scrub.c85
1 files changed, 59 insertions, 26 deletions
diff --git a/fs/btrfs/scrub.c b/fs/btrfs/scrub.c
index 902819d3cf41..6dcd36d7b849 100644
--- a/fs/btrfs/scrub.c
+++ b/fs/btrfs/scrub.c
@@ -339,7 +339,9 @@ static struct full_stripe_lock *insert_full_stripe_lock(
}
}
- /* Insert new lock */
+ /*
+ * Insert new lock.
+ */
ret = kmalloc(sizeof(*ret), GFP_KERNEL);
if (!ret)
return ERR_PTR(-ENOMEM);
@@ -568,12 +570,11 @@ static void scrub_put_ctx(struct scrub_ctx *sctx)
scrub_free_ctx(sctx);
}
-static noinline_for_stack
-struct scrub_ctx *scrub_setup_ctx(struct btrfs_device *dev, int is_dev_replace)
+static noinline_for_stack struct scrub_ctx *scrub_setup_ctx(
+ struct btrfs_fs_info *fs_info, int is_dev_replace)
{
struct scrub_ctx *sctx;
int i;
- struct btrfs_fs_info *fs_info = dev->fs_info;
sctx = kzalloc(sizeof(*sctx), GFP_KERNEL);
if (!sctx)
@@ -582,7 +583,7 @@ struct scrub_ctx *scrub_setup_ctx(struct btrfs_device *dev, int is_dev_replace)
sctx->is_dev_replace = is_dev_replace;
sctx->pages_per_rd_bio = SCRUB_PAGES_PER_RD_BIO;
sctx->curr = -1;
- sctx->fs_info = dev->fs_info;
+ sctx->fs_info = fs_info;
for (i = 0; i < SCRUB_BIOS_PER_SCTX; ++i) {
struct scrub_bio *sbio;
@@ -832,6 +833,7 @@ static int scrub_handle_errored_block(struct scrub_block *sblock_to_check)
int page_num;
int success;
bool full_stripe_locked;
+ unsigned int nofs_flag;
static DEFINE_RATELIMIT_STATE(_rs, DEFAULT_RATELIMIT_INTERVAL,
DEFAULT_RATELIMIT_BURST);
@@ -857,6 +859,16 @@ static int scrub_handle_errored_block(struct scrub_block *sblock_to_check)
dev = sblock_to_check->pagev[0]->dev;
/*
+ * We must use GFP_NOFS because the scrub task might be waiting for a
+ * worker task executing this function and in turn a transaction commit
+ * might be waiting the scrub task to pause (which needs to wait for all
+ * the worker tasks to complete before pausing).
+ * We do allocations in the workers through insert_full_stripe_lock()
+ * and scrub_add_page_to_wr_bio(), which happens down the call chain of
+ * this function.
+ */
+ nofs_flag = memalloc_nofs_save();
+ /*
* For RAID5/6, race can happen for a different device scrub thread.
* For data corruption, Parity and Data threads will both try
* to recovery the data.
@@ -865,6 +877,7 @@ static int scrub_handle_errored_block(struct scrub_block *sblock_to_check)
*/
ret = lock_full_stripe(fs_info, logical, &full_stripe_locked);
if (ret < 0) {
+ memalloc_nofs_restore(nofs_flag);
spin_lock(&sctx->stat_lock);
if (ret == -ENOMEM)
sctx->stat.malloc_errors++;
@@ -904,7 +917,7 @@ static int scrub_handle_errored_block(struct scrub_block *sblock_to_check)
*/
sblocks_for_recheck = kcalloc(BTRFS_MAX_MIRRORS,
- sizeof(*sblocks_for_recheck), GFP_NOFS);
+ sizeof(*sblocks_for_recheck), GFP_KERNEL);
if (!sblocks_for_recheck) {
spin_lock(&sctx->stat_lock);
sctx->stat.malloc_errors++;
@@ -1202,6 +1215,7 @@ out:
}
ret = unlock_full_stripe(fs_info, logical, full_stripe_locked);
+ memalloc_nofs_restore(nofs_flag);
if (ret < 0)
return ret;
return 0;
@@ -3540,7 +3554,7 @@ int scrub_enumerate_chunks(struct scrub_ctx *sctx,
if (!ret && sctx->is_dev_replace) {
/*
* If we are doing a device replace wait for any tasks
- * that started dellaloc right before we set the block
+ * that started delalloc right before we set the block
* group to RO mode, as they might have just allocated
* an extent from it or decided they could do a nocow
* write. And if any such tasks did that, wait for their
@@ -3596,11 +3610,12 @@ int scrub_enumerate_chunks(struct scrub_ctx *sctx,
break;
}
- btrfs_dev_replace_write_lock(&fs_info->dev_replace);
+ down_write(&fs_info->dev_replace.rwsem);
dev_replace->cursor_right = found_key.offset + length;
dev_replace->cursor_left = found_key.offset;
dev_replace->item_needs_writeback = 1;
- btrfs_dev_replace_write_unlock(&fs_info->dev_replace);
+ up_write(&dev_replace->rwsem);
+
ret = scrub_chunk(sctx, scrub_dev, chunk_offset, length,
found_key.offset, cache);
@@ -3636,10 +3651,10 @@ int scrub_enumerate_chunks(struct scrub_ctx *sctx,
scrub_pause_off(fs_info);
- btrfs_dev_replace_write_lock(&fs_info->dev_replace);
+ down_write(&fs_info->dev_replace.rwsem);
dev_replace->cursor_left = dev_replace->cursor_right;
dev_replace->item_needs_writeback = 1;
- btrfs_dev_replace_write_unlock(&fs_info->dev_replace);
+ up_write(&fs_info->dev_replace.rwsem);
if (ro_set)
btrfs_dec_block_group_ro(cache);
@@ -3772,6 +3787,7 @@ int btrfs_scrub_dev(struct btrfs_fs_info *fs_info, u64 devid, u64 start,
struct scrub_ctx *sctx;
int ret;
struct btrfs_device *dev;
+ unsigned int nofs_flag;
if (btrfs_fs_closing(fs_info))
return -EINVAL;
@@ -3813,13 +3829,18 @@ int btrfs_scrub_dev(struct btrfs_fs_info *fs_info, u64 devid, u64 start,
return -EINVAL;
}
+ /* Allocate outside of device_list_mutex */
+ sctx = scrub_setup_ctx(fs_info, is_dev_replace);
+ if (IS_ERR(sctx))
+ return PTR_ERR(sctx);
mutex_lock(&fs_info->fs_devices->device_list_mutex);
dev = btrfs_find_device(fs_info, devid, NULL, NULL);
if (!dev || (test_bit(BTRFS_DEV_STATE_MISSING, &dev->dev_state) &&
!is_dev_replace)) {
mutex_unlock(&fs_info->fs_devices->device_list_mutex);
- return -ENODEV;
+ ret = -ENODEV;
+ goto out_free_ctx;
}
if (!is_dev_replace && !readonly &&
@@ -3827,7 +3848,8 @@ int btrfs_scrub_dev(struct btrfs_fs_info *fs_info, u64 devid, u64 start,
mutex_unlock(&fs_info->fs_devices->device_list_mutex);
btrfs_err_in_rcu(fs_info, "scrub: device %s is not writable",
rcu_str_deref(dev->name));
- return -EROFS;
+ ret = -EROFS;
+ goto out_free_ctx;
}
mutex_lock(&fs_info->scrub_lock);
@@ -3835,34 +3857,29 @@ int btrfs_scrub_dev(struct btrfs_fs_info *fs_info, u64 devid, u64 start,
test_bit(BTRFS_DEV_STATE_REPLACE_TGT, &dev->dev_state)) {
mutex_unlock(&fs_info->scrub_lock);
mutex_unlock(&fs_info->fs_devices->device_list_mutex);
- return -EIO;
+ ret = -EIO;
+ goto out_free_ctx;
}
- btrfs_dev_replace_read_lock(&fs_info->dev_replace);
+ down_read(&fs_info->dev_replace.rwsem);
if (dev->scrub_ctx ||
(!is_dev_replace &&
btrfs_dev_replace_is_ongoing(&fs_info->dev_replace))) {
- btrfs_dev_replace_read_unlock(&fs_info->dev_replace);
+ up_read(&fs_info->dev_replace.rwsem);
mutex_unlock(&fs_info->scrub_lock);
mutex_unlock(&fs_info->fs_devices->device_list_mutex);
- return -EINPROGRESS;
+ ret = -EINPROGRESS;
+ goto out_free_ctx;
}
- btrfs_dev_replace_read_unlock(&fs_info->dev_replace);
+ up_read(&fs_info->dev_replace.rwsem);
ret = scrub_workers_get(fs_info, is_dev_replace);
if (ret) {
mutex_unlock(&fs_info->scrub_lock);
mutex_unlock(&fs_info->fs_devices->device_list_mutex);
- return ret;
+ goto out_free_ctx;
}
- sctx = scrub_setup_ctx(dev, is_dev_replace);
- if (IS_ERR(sctx)) {
- mutex_unlock(&fs_info->scrub_lock);
- mutex_unlock(&fs_info->fs_devices->device_list_mutex);
- scrub_workers_put(fs_info);
- return PTR_ERR(sctx);
- }
sctx->readonly = readonly;
dev->scrub_ctx = sctx;
mutex_unlock(&fs_info->fs_devices->device_list_mutex);
@@ -3875,6 +3892,16 @@ int btrfs_scrub_dev(struct btrfs_fs_info *fs_info, u64 devid, u64 start,
atomic_inc(&fs_info->scrubs_running);
mutex_unlock(&fs_info->scrub_lock);
+ /*
+ * In order to avoid deadlock with reclaim when there is a transaction
+ * trying to pause scrub, make sure we use GFP_NOFS for all the
+ * allocations done at btrfs_scrub_pages() and scrub_pages_for_parity()
+ * invoked by our callees. The pausing request is done when the
+ * transaction commit starts, and it blocks the transaction until scrub
+ * is paused (done at specific points at scrub_stripe() or right above
+ * before incrementing fs_info->scrubs_running).
+ */
+ nofs_flag = memalloc_nofs_save();
if (!is_dev_replace) {
/*
* by holding device list mutex, we can
@@ -3887,6 +3914,7 @@ int btrfs_scrub_dev(struct btrfs_fs_info *fs_info, u64 devid, u64 start,
if (!ret)
ret = scrub_enumerate_chunks(sctx, dev, start, end);
+ memalloc_nofs_restore(nofs_flag);
wait_event(sctx->list_wait, atomic_read(&sctx->bios_in_flight) == 0);
atomic_dec(&fs_info->scrubs_running);
@@ -3905,6 +3933,11 @@ int btrfs_scrub_dev(struct btrfs_fs_info *fs_info, u64 devid, u64 start,
scrub_put_ctx(sctx);
return ret;
+
+out_free_ctx:
+ scrub_free_ctx(sctx);
+
+ return ret;
}
void btrfs_scrub_pause(struct btrfs_fs_info *fs_info)
Copyright © 1996 – 2023 Jason A. Donenfeld. All Rights Reverse Engineered.