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lib/sbitmap: define swap_lock as raw_spinlock_t
jira LE-4034 Rebuild_History Non-Buildable kernel-4.18.0-553.72.1.el8_10 commit-author Ming Lei <ming.lei@redhat.com> commit 65f666c Empty-Commit: Cherry-Pick Conflicts during history rebuild. Will be included in final tarball splat. Ref for failed cherry-pick at: ciq/ciq_backports/kernel-4.18.0-553.72.1.el8_10/65f666c6.failed When called from sbitmap_queue_get(), sbitmap_deferred_clear() may be run with preempt disabled. In RT kernel, spin_lock() can sleep, then warning of "BUG: sleeping function called from invalid context" can be triggered. Fix it by replacing it with raw_spin_lock. Cc: Yang Yang <yang.yang@vivo.com> Fixes: 72d04bd ("sbitmap: fix io hung due to race on sbitmap_word::cleared") Signed-off-by: Ming Lei <ming.lei@redhat.com> Reviewed-by: Yang Yang <yang.yang@vivo.com> Link: https://lore.kernel.org/r/20240919021709.511329-1-ming.lei@redhat.com Signed-off-by: Jens Axboe <axboe@kernel.dk> (cherry picked from commit 65f666c) Signed-off-by: Jonathan Maple <jmaple@ciq.com> # Conflicts: # include/linux/sbitmap.h # lib/sbitmap.c
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‎ciq/ciq_backports/kernel-4.18.0-553.72.1.el8_10/65f666c6.failed‎

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lib/sbitmap: define swap_lock as raw_spinlock_t
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jira LE-4034
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Rebuild_History Non-Buildable kernel-4.18.0-553.72.1.el8_10
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commit-author Ming Lei <ming.lei@redhat.com>
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commit 65f666c6203600053478ce8e34a1db269a8701c9
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Empty-Commit: Cherry-Pick Conflicts during history rebuild.
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Will be included in final tarball splat. Ref for failed cherry-pick at:
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ciq/ciq_backports/kernel-4.18.0-553.72.1.el8_10/65f666c6.failed
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When called from sbitmap_queue_get(), sbitmap_deferred_clear() may be run
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with preempt disabled. In RT kernel, spin_lock() can sleep, then warning
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of "BUG: sleeping function called from invalid context" can be triggered.
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Fix it by replacing it with raw_spin_lock.
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Cc: Yang Yang <yang.yang@vivo.com>
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Fixes: 72d04bdcf3f7 ("sbitmap: fix io hung due to race on sbitmap_word::cleared")
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Signed-off-by: Ming Lei <ming.lei@redhat.com>
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Reviewed-by: Yang Yang <yang.yang@vivo.com>
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Link: https://lore.kernel.org/r/20240919021709.511329-1-ming.lei@redhat.com
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Signed-off-by: Jens Axboe <axboe@kernel.dk>
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(cherry picked from commit 65f666c6203600053478ce8e34a1db269a8701c9)
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Signed-off-by: Jonathan Maple <jmaple@ciq.com>
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# Conflicts:
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# include/linux/sbitmap.h
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# lib/sbitmap.c
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diff --cc include/linux/sbitmap.h
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index c5364c7c3ae5,189140bf11fc..000000000000
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--- a/include/linux/sbitmap.h
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+++ b/include/linux/sbitmap.h
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@@@ -40,9 -38,9 +40,13 @@@ struct sbitmap_word
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unsigned long cleared ____cacheline_aligned_in_smp;
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/**
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- * @swap_lock: serializes simultaneous updates of ->word and ->cleared
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+ * @swap_lock: Held while swapping word <-> cleared
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*/
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++<<<<<<< HEAD
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+ RH_KABI_DEPRECATE(spinlock_t, swap_lock)
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++=======
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+ raw_spinlock_t swap_lock;
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++>>>>>>> 65f666c62036 (lib/sbitmap: define swap_lock as raw_spinlock_t)
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} ____cacheline_aligned_in_smp;
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/**
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diff --cc lib/sbitmap.c
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index 59f985b64b05,d3412984170c..000000000000
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--- a/lib/sbitmap.c
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+++ b/lib/sbitmap.c
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@@@ -76,12 -60,30 +76,34 @@@ static inline void update_alloc_hint_af
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/*
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* See if we have deferred clears that we can batch move
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*/
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-static inline bool sbitmap_deferred_clear(struct sbitmap_word *map,
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- unsigned int depth, unsigned int alloc_hint, bool wrap)
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+static inline bool sbitmap_deferred_clear(struct sbitmap_word *map)
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{
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- unsigned long mask, word_mask;
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+ unsigned long mask;
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++<<<<<<< HEAD
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+ if (!READ_ONCE(map->cleared))
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+ return false;
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++=======
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+ guard(raw_spinlock_irqsave)(&map->swap_lock);
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+
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+ if (!map->cleared) {
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+ if (depth == 0)
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+ return false;
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+
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+ word_mask = (~0UL) >> (BITS_PER_LONG - depth);
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+ /*
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+ * The current behavior is to always retry after moving
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+ * ->cleared to word, and we change it to retry in case
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+ * of any free bits. To avoid an infinite loop, we need
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+ * to take wrap & alloc_hint into account, otherwise a
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+ * soft lockup may occur.
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+ */
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+ if (!wrap && alloc_hint)
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+ word_mask &= ~((1UL << alloc_hint) - 1);
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+
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+ return (READ_ONCE(map->word) & word_mask) != word_mask;
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+ }
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++>>>>>>> 65f666c62036 (lib/sbitmap: define swap_lock as raw_spinlock_t)
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/*
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* First get a stable cleared mask, setting the old mask to 0.
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@@@ -119,24 -122,21 +141,29 @@@ int sbitmap_init_node(struct sbitmap *s
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return 0;
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}
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- if (alloc_hint) {
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- if (init_alloc_hint(sb, flags))
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- return -ENOMEM;
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- } else {
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- sb->alloc_hint = NULL;
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- }
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-
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- sb->map = kvzalloc_node(sb->map_nr * sizeof(*sb->map), flags, node);
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+ /*
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+ * RHEL8: sb->alloc_hint is kept in an additional sb->map array element prior
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+ * to the actual sb->map due to KABI (it was not possible to add it to struct sbitmap)
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+ */
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+ sb->map = kvzalloc_node((sb->map_nr + 1) * sizeof(*sb->map), flags, node);
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if (!sb->map) {
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- free_percpu(sb->alloc_hint);
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return -ENOMEM;
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}
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+ sb->map++;
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++<<<<<<< HEAD
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+ if (alloc_hint) {
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+ if (init_alloc_hint(sb, flags)) {
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+ kfree(--sb->map);
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+ return -ENOMEM;
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+ }
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+ } else {
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+ *SB_ALLOC_HINT_PTR(sb) = NULL;
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+ }
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++=======
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+ for (i = 0; i < sb->map_nr; i++)
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+ raw_spin_lock_init(&sb->map[i].swap_lock);
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++>>>>>>> 65f666c62036 (lib/sbitmap: define swap_lock as raw_spinlock_t)
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return 0;
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}
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* Unmerged path include/linux/sbitmap.h
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* Unmerged path lib/sbitmap.c

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