Decouple disk from stripe (#11737)

* Pass `fd` in to `flush_aggregate_write_buffer`

* Push down `fd` field to `StripeSM`

* Pass `hw_sector_size` in to `_clear_init`

* Push down `disk` field to `StripeSM`

Author: JosiahWI

src/iocore/cache/CacheDir.cc

@@ -428,7 +428,7 @@ check_bucket_not_contains(Dir *b, Dir *e, Dir *seg)
 }
 
 void
-freelist_clean(int s, Stripe *stripe)
+freelist_clean(int s, StripeSM *stripe)
 {
   dir_clean_segment(s, stripe);
   if (stripe->header->freelist[s]) {
@@ -452,7 +452,7 @@ freelist_clean(int s, Stripe *stripe)
 }
 
 inline Dir *
-freelist_pop(int s, Stripe *stripe)
+freelist_pop(int s, StripeSM *stripe)
 {
   Dir *seg = stripe->dir_segment(s);
   Dir *e   = dir_from_offset(stripe->header->freelist[s], seg);

src/iocore/cache/Stripe.cc

@@ -85,24 +85,22 @@ struct StripeInitInfo {
 //
 
 Stripe::Stripe(CacheDisk *disk, off_t blocks, off_t dir_skip, int avg_obj_size, int fragment_size)
-  : fd{disk->fd},
-    frag_size{fragment_size},
+  : frag_size{fragment_size},
     skip{ROUND_TO_STORE_BLOCK((dir_skip < START_POS ? START_POS : dir_skip))},
     start{skip},
-    len{blocks * STORE_BLOCK_SIZE},
-    disk{disk}
+    len{blocks * STORE_BLOCK_SIZE}
 {
   ink_assert(this->len < MAX_STRIPE_SIZE);
 
-  this->_init_hash_text(disk->path, blocks, dir_skip);
+  this->_init_hash_text(disk, blocks, dir_skip);
   this->_init_data(STORE_BLOCK_SIZE, avg_obj_size);
   this->_init_directory(this->dirlen(), this->headerlen(), DIRECTORY_FOOTER_SIZE);
 }
 
 void
-Stripe::_init_hash_text(char const *seed, off_t blocks, off_t dir_skip)
+Stripe::_init_hash_text(CacheDisk const *disk, off_t blocks, off_t dir_skip)
 {
-  char const  *seed_str       = this->disk->hash_base_string ? this->disk->hash_base_string : seed;
+  char const  *seed_str       = disk->hash_base_string ? disk->hash_base_string : disk->path;
   const size_t hash_seed_size = strlen(seed_str);
   const size_t hash_text_size = hash_seed_size + 32;
 
@@ -323,7 +321,7 @@ Stripe::dir_check()
 }
 
 void
-Stripe::_clear_init()
+Stripe::_clear_init(std::uint32_t hw_sector_size)
 {
   size_t dir_len = this->dirlen();
   memset(this->raw_dir, 0, dir_len);
@@ -337,7 +335,7 @@ Stripe::_clear_init()
   this->header->cycle                                              = 0;
   this->header->create_time                                        = time(nullptr);
   this->header->dirty                                              = 0;
-  this->sector_size = this->header->sector_size = this->disk->hw_sector_size;
+  this->sector_size = this->header->sector_size = hw_sector_size;
   *this->footer                                 = *this->header;
 }
 
@@ -359,12 +357,12 @@ Stripe::_init_dir()
 }
 
 bool
-Stripe::flush_aggregate_write_buffer()
+Stripe::flush_aggregate_write_buffer(int fd)
 {
   // set write limit
   this->header->agg_pos = this->header->write_pos + this->_write_buffer.get_buffer_pos();
 
-  if (!this->_write_buffer.flush(this->fd, this->header->write_pos)) {
+  if (!this->_write_buffer.flush(fd, this->header->write_pos)) {
     return false;
   }
   this->header->last_write_pos  = this->header->write_pos;

src/iocore/cache/Stripe.h

@@ -85,7 +85,6 @@ class Stripe
 {
 public:
   ats_scoped_str hash_text;
-  int            fd{-1};
   int            frag_size{-1};
 
   char                *raw_dir{nullptr};
@@ -100,8 +99,7 @@ class Stripe
   off_t                len{};
   off_t                data_blocks{};
 
-  CacheDisk *const disk{};
-  uint32_t         sector_size{};
+  uint32_t sector_size{};
 
   CacheVol *cache_vol{};
 
@@ -172,12 +170,12 @@ class Stripe
 protected:
   AggregateWriteBuffer _write_buffer;
 
-  void _clear_init();
+  void _clear_init(std::uint32_t hw_sector_size);
   void _init_dir();
-  bool flush_aggregate_write_buffer();
+  bool flush_aggregate_write_buffer(int fd);
 
 private:
-  void _init_hash_text(char const *seed, off_t blocks, off_t dir_skip);
+  void _init_hash_text(CacheDisk const *disk, off_t blocks, off_t dir_skip);
   void _init_data(off_t store_block_size, int avg_obj_size = -1);
   void _init_data_internal(int avg_obj_size = -1); // Defaults to cache_config_min_average_object_size;
   void _init_directory(std::size_t directory_size, int header_size, int footer_size);

src/iocore/cache/StripeSM.cc

@@ -115,6 +115,8 @@ struct StripeInitInfo {
 StripeSM::StripeSM(CacheDisk *disk, off_t blocks, off_t dir_skip, int avg_obj_size, int fragment_size)
   : Continuation(new_ProxyMutex()),
     Stripe{disk, blocks, dir_skip, avg_obj_size, fragment_size},
+    fd{disk->fd},
+    disk{disk},
     _preserved_dirs{static_cast<int>(len)}
 {
   open_dir.mutex = this->mutex;
@@ -152,7 +154,7 @@ int
 StripeSM::clear_dir()
 {
   size_t dir_len = this->dirlen();
-  this->_clear_init();
+  this->_clear_init(this->disk->hw_sector_size);
 
   if (pwrite(this->fd, this->raw_dir, dir_len, this->skip) < 0) {
     Warning("unable to clear cache directory '%s'", this->hash_text.get());
@@ -272,7 +274,7 @@ int
 StripeSM::clear_dir_aio()
 {
   size_t dir_len = this->dirlen();
-  this->_clear_init();
+  this->_clear_init(this->disk->hw_sector_size);
 
   SET_HANDLER(&StripeSM::handle_dir_clear);
 
@@ -1339,7 +1341,7 @@ StripeSM::shutdown(EThread *shutdown_thread)
   // directories have not been inserted for these writes
   if (!this->_write_buffer.is_empty()) {
     Dbg(dbg_ctl_cache_dir_sync, "Dir %s: flushing agg buffer first", this->hash_text.get());
-    this->flush_aggregate_write_buffer();
+    this->flush_aggregate_write_buffer(this->fd);
   }
 
   // We already asserted that dirlen > 0.

src/iocore/cache/StripeSM.h

@@ -66,6 +66,7 @@ class StripeSM : public Continuation, public Stripe
 {
 public:
   CryptoHash hash_id;
+  int        fd{-1};
 
   int hit_evacuate_window{};
 
@@ -77,6 +78,8 @@ class StripeSM : public Continuation, public Stripe
 
   Event *trigger = nullptr;
 
+  CacheDisk *disk{};
+
   OpenDir              open_dir;
   RamCache            *ram_cache = nullptr;
   DLL<EvacuationBlock> lookaside[LOOKASIDE_SIZE];