Hold db_mtx when updating db_state

Commit 555ef90 did some general code refactoring for
dmu_buf_will_not_fill() and dmu_buf_will_fill(). However, the db_mtx was
not held when update db->db_state in those code block. The rest of the
dbuf code always holds the db_mtx when updating db_state. This is
important because cv_wait() db_changed is used to check for db_state
changes.

Updating dmu_buf_will_not_fill() and dmu_buf_will_fill() to hold the
db_mtx when updating db_state.

Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Brian Atkinson <batkinson@lanl.gov>
Closes #14875
This commit is contained in:
Brian Atkinson 2023-05-19 16:05:53 -04:00 committed by GitHub
parent 577e835f30
commit ad0a554614
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@ -2716,8 +2716,10 @@ dmu_buf_will_not_fill(dmu_buf_t *db_fake, dmu_tx_t *tx)
{
dmu_buf_impl_t *db = (dmu_buf_impl_t *)db_fake;
mutex_enter(&db->db_mtx);
db->db_state = DB_NOFILL;
DTRACE_SET_STATE(db, "allocating NOFILL buffer");
mutex_exit(&db->db_mtx);
dbuf_noread(db);
(void) dbuf_dirty(db, tx);
@ -2736,6 +2738,7 @@ dmu_buf_will_fill(dmu_buf_t *db_fake, dmu_tx_t *tx)
ASSERT(db->db.db_object != DMU_META_DNODE_OBJECT ||
dmu_tx_private_ok(tx));
mutex_enter(&db->db_mtx);
if (db->db_state == DB_NOFILL) {
/*
* Block cloning: We will be completely overwriting a block
@ -2743,11 +2746,10 @@ dmu_buf_will_fill(dmu_buf_t *db_fake, dmu_tx_t *tx)
* pending clone and mark the block as uncached. This will be
* as if the clone was never done.
*/
mutex_enter(&db->db_mtx);
VERIFY(!dbuf_undirty(db, tx));
mutex_exit(&db->db_mtx);
db->db_state = DB_UNCACHED;
}
mutex_exit(&db->db_mtx);
dbuf_noread(db);
(void) dbuf_dirty(db, tx);