Changeset 402a18f in mainline for uspace/lib/libblock/libblock.c

Timestamp:

2009-08-27T19:57:03Z (15 years ago)

Author:

Jakub Jermar <jakub@…>

Branches:

lfn, master, serial, ticket/834-toolchain-update, topic/msim-upgrade, topic/simplify-dev-export

Children:

ff62c6d

Parents:

cd688d9

Message:

Let block_get() and block_put() deal with I/O errors.

File:

• uspace/lib/libblock/libblock.c (modified) (11 diffs)

uspace/lib/libblock/libblock.c

@@ -331 +331 @@
         link_t *l;
         unsigned long key = boff;
+        int rc = EOK;
         
         devcon = devcon_search(dev_handle);
@@ -350 +351 @@
                 if (b->refcnt++ == 0)
                         list_remove(&b->free_link);
+                if (b->toxic)
+                        rc = EIO;
                 fibril_mutex_unlock(&b->lock);
                 fibril_mutex_unlock(&cache->lock);
@@ -356 +359 @@
                  * The block was not found in the cache.
                  */
-                int rc;
-
                 if (cache_can_grow(cache)) {
                         /*
@@ -402 +403 @@
                                     cache->block_size);
                                 fibril_mutex_unlock(&devcon->com_area_lock);
-                                assert(rc == EOK);
+                                if (rc != EOK) {
+                                        /*
+                                         * We did not manage to write the block
+                                         * to the device. Keep it around for
+                                         * another try. Hopefully, we will grab
+                                         * another block next time.
+                                         */
+                                        fibril_mutex_unlock(&b->lock);
+                                        goto retry;
+                                }
                                 b->dirty = false;
                                 if (!fibril_mutex_trylock(&cache->lock)) {
@@ -446 +456 @@
                         fibril_mutex_lock(&devcon->com_area_lock);
                         rc = read_block(devcon, b->boff, cache->block_size);
-                        assert(rc == EOK);
                         memcpy(b->data, devcon->com_area, cache->block_size);
                         fibril_mutex_unlock(&devcon->com_area_lock);
-                }
+                        if (rc != EOK) 
+                                b->toxic = true;
+                } else
+                        rc = EOK;
 
                 fibril_mutex_unlock(&b->lock);
         }
         *block = b;
-        return EOK;
+        return rc;
 }
 
@@ -471 +483 @@
         unsigned blocks_cached;
         enum cache_mode mode;
-        int rc;
+        int rc = EOK;
 
         assert(devcon);
@@ -492 +504 @@
          */
         fibril_mutex_lock(&block->lock);
+        if (block->toxic)
+                block->dirty = false;   /* will not write back toxic block */
         if (block->dirty && (block->refcnt == 1) &&
             (blocks_cached > CACHE_HI_WATERMARK || mode != CACHE_MODE_WB)) {
@@ -497 +511 @@
                 memcpy(devcon->com_area, block->data, block->size);
                 rc = write_block(devcon, block->boff, block->size);
-                assert(rc == EOK);
                 fibril_mutex_unlock(&devcon->com_area_lock);
                 block->dirty = false;
@@ -508 +521 @@
                 /*
                  * Last reference to the block was dropped. Either free the
-                 * block or put it on the free list.
+                 * block or put it on the free list. In case of an I/O error,
+                 * free the block.
                  */
-                if (cache->blocks_cached > CACHE_HI_WATERMARK) {
-                        /*
-                         * Currently there are too many cached blocks.
+                if ((cache->blocks_cached > CACHE_HI_WATERMARK) ||
+                    (rc != EOK)) {
+                        /*
+                         * Currently there are too many cached blocks or there
+                         * was an I/O error when writing the block back to the
+                         * device.
                          */
                         if (block->dirty) {
@@ -533 +550 @@
                         cache->blocks_cached--;
                         fibril_mutex_unlock(&cache->lock);
-                        return;
+                        return rc;
                 }
                 /*
@@ -553 +570 @@
         fibril_mutex_unlock(&cache->lock);
 
-        return EOK;
+        return rc;
 }