From: Alex Markuze <amarkuze@redhat.com>
Date: Tue, 18 Mar 2025 20:04:31 +0000 (+0000)
Subject: pf iterator debug
X-Git-Url: http://git-server-git.apps.pok.os.sepia.ceph.com/?a=commitdiff_plain;h=e9a817800b25cf3143bb5c71b3f3e8383f566a66;p=ceph-client.git

pf iterator debug
---

diff --git a/include/linux/ceph/ceph_san_logger.h b/include/linux/ceph/ceph_san_logger.h
index b4c2cec7cd5b..6d6dc6d00670 100644
--- a/include/linux/ceph/ceph_san_logger.h
+++ b/include/linux/ceph/ceph_san_logger.h
@@ -44,6 +44,7 @@ struct ceph_san_log_iter {
     struct cephsan_pagefrag *pf;    /* Pagefrag being iterated */
     u64 current_offset;             /* Current offset in pagefrag */
     u64 end_offset;                 /* End offset in pagefrag */
+    u64 prev_offset;               /* Previous offset for debugging */
 };
 
 /* Initialize the iterator for a specific pagefrag */
diff --git a/include/linux/ceph/ceph_san_pagefrag.h b/include/linux/ceph/ceph_san_pagefrag.h
index fc7e08246dc5..3ea5ba460d1f 100644
--- a/include/linux/ceph/ceph_san_pagefrag.h
+++ b/include/linux/ceph/ceph_san_pagefrag.h
@@ -15,6 +15,7 @@ struct cephsan_pagefrag {
     spinlock_t lock;        /* protects head and tail */
     unsigned int head;
     unsigned int tail;
+    unsigned int alloc_count;
 };
 
 int cephsan_pagefrag_init(struct cephsan_pagefrag *pf);
diff --git a/net/ceph/ceph_san_logger.c b/net/ceph/ceph_san_logger.c
index faa564250595..0d5e76146223 100644
--- a/net/ceph/ceph_san_logger.c
+++ b/net/ceph/ceph_san_logger.c
@@ -244,6 +244,7 @@ void ceph_san_log_iter_init(struct ceph_san_log_iter *iter, struct cephsan_pagef
     iter->pf = pf;
     iter->current_offset = pf->tail;
     iter->end_offset = pf->head;
+    iter->prev_offset = pf->tail;
 }
 EXPORT_SYMBOL(ceph_san_log_iter_init);
 
@@ -257,18 +258,33 @@ struct ceph_san_log_entry *ceph_san_log_iter_next(struct ceph_san_log_iter *iter
 {
     struct ceph_san_log_entry *entry;
 
-    if (!iter->pf || iter->current_offset== iter->end_offset)
+    if (!iter->pf || iter->current_offset == iter->end_offset)
         return NULL;
 
     /* Get current entry */
     entry = cephsan_pagefrag_get_ptr(iter->pf, iter->current_offset);
     /* Verify entry is valid */
     if (!entry || entry->debug_poison != CEPH_SAN_LOG_ENTRY_POISON || entry->len == 0) {
+        /* Get previous entry if available */
+        struct ceph_san_log_entry *prev_entry = NULL;
+        prev_entry = cephsan_pagefrag_get_ptr(iter->pf, iter->prev_offset);
+        pr_err("Previous entry: entry=%px poison=%x len=%u prev_offset=%llu\n",
+                prev_entry, prev_entry->debug_poison, prev_entry->len, iter->prev_offset);
+
+        iter->prev_offset = iter->current_offset;
         iter->current_offset = iter->end_offset;
+        pr_err("Pagefrag corruption detected: entry=%px poison=%x len=%u\n"
+               "pf: head=%u tail=%u buffer=%px alloc_count=%u prev_offset=%llu\n",
+               entry, entry->debug_poison, entry->len,
+               iter->pf->head, iter->pf->tail, iter->pf->buffer,
+               iter->pf->alloc_count, iter->prev_offset);
+
         BUG_ON(entry->debug_poison != CEPH_SAN_LOG_ENTRY_POISON);
         return NULL;
     }
 
+    /* Store current offset before moving to next */
+    iter->prev_offset = iter->current_offset;
     /* Move to next entry */
     iter->current_offset += entry->len & CEPHSAN_PAGEFRAG_MASK;
 
diff --git a/net/ceph/ceph_san_pagefrag.c b/net/ceph/ceph_san_pagefrag.c
index 416f969810cb..22b37f1545e3 100644
--- a/net/ceph/ceph_san_pagefrag.c
+++ b/net/ceph/ceph_san_pagefrag.c
@@ -61,6 +61,7 @@ u64 cephsan_pagefrag_alloc(struct cephsan_pagefrag *pf, unsigned int n)
     if (pf->tail > pf->head) {
         if (pf->tail - pf->head > n) {
             pf->head += n;
+            pf->alloc_count++;
             return ((u64)n << 32) | prev_head;
         } else {
             return 0;
@@ -73,6 +74,7 @@ u64 cephsan_pagefrag_alloc(struct cephsan_pagefrag *pf, unsigned int n)
         if (unlikely(delta < 64)) {
             n += delta;
             pf->head = 0;
+            pf->alloc_count++;
             return ((u64)n << 32) | prev_head;
         }
         pf->head += n;
@@ -81,6 +83,7 @@ u64 cephsan_pagefrag_alloc(struct cephsan_pagefrag *pf, unsigned int n)
         if (pf->tail > n) {
             /* Need to wrap around return a partial allocation*/
             pf->head = n;
+            pf->alloc_count++;
             return ((u64)(delta + n) << 32) | prev_head;
         } else {
             return 0;
@@ -177,6 +180,7 @@ void cephsan_pagefrag_reset(struct cephsan_pagefrag *pf)
     spin_lock(&pf->lock);
     pf->head = 0;
     pf->tail = 0;
+    pf->alloc_count = 0;
     spin_unlock(&pf->lock);
 }
 EXPORT_SYMBOL(cephsan_pagefrag_reset);