minikconf: do not include variables from MINIKCONF_ARGS in config-all-devices.mak

[mirror_qemu.git] / nbd / server.c

diff --git a/nbd/server.c b/nbd/server.c
index fd013a2817a83fef4eae22993c2456ab2b0c0bf8..10faedcfc55de9eba89fa0c123fe689b6f600b98 100644 (file)
--- a/nbd/server.c
+++ b/nbd/server.c
@@ -21,15 +21,18 @@
 #include "qapi/error.h"
 #include "trace.h"
 #include "nbd-internal.h"
+#include "qemu/units.h"
 
 #define NBD_META_ID_BASE_ALLOCATION 0
 #define NBD_META_ID_DIRTY_BITMAP 1
 
-/* NBD_MAX_BITMAP_EXTENTS: 1 mb of extents data. An empirical
+/*
+ * NBD_MAX_BLOCK_STATUS_EXTENTS: 1 MiB of extents data. An empirical
  * constant. If an increase is needed, note that the NBD protocol
  * recommends no larger than 32 mb, so that the client won't consider
- * the reply as a denial of service attack. */
-#define NBD_MAX_BITMAP_EXTENTS (0x100000 / 8)
+ * the reply as a denial of service attack.
+ */
+#define NBD_MAX_BLOCK_STATUS_EXTENTS (1 * MiB / 8)
 
 static int system_errno_to_nbd_errno(int err)
 {
@@ -124,6 +127,8 @@ struct NBDClient {
     int nb_requests;
     bool closing;
 
+    uint32_t check_align; /* If non-zero, check for aligned client requests */
+
     bool structured_reply;
     NBDExportMetaContexts export_meta;
 
@@ -533,6 +538,7 @@ static int nbd_negotiate_handle_info(NBDClient *client, uint16_t myflags,
     bool blocksize = false;
     uint32_t sizes[3];
     char buf[sizeof(uint64_t) + sizeof(uint16_t)];
+    uint32_t check_align = 0;
 
     /* Client sends:
         4 bytes: L, name length (can be 0)
@@ -607,13 +613,16 @@ static int nbd_negotiate_handle_info(NBDClient *client, uint16_t myflags,
     /* Send NBD_INFO_BLOCK_SIZE always, but tweak the minimum size
      * according to whether the client requested it, and according to
      * whether this is OPT_INFO or OPT_GO. */
-    /* minimum - 1 for back-compat, or 512 if client is new enough.
-     * TODO: consult blk_bs(blk)->bl.request_alignment? */
-    sizes[0] =
-            (client->opt == NBD_OPT_INFO || blocksize) ? BDRV_SECTOR_SIZE : 1;
+    /* minimum - 1 for back-compat, or actual if client will obey it. */
+    if (client->opt == NBD_OPT_INFO || blocksize) {
+        check_align = sizes[0] = blk_get_request_alignment(exp->blk);
+    } else {
+        sizes[0] = 1;
+    }
+    assert(sizes[0] <= NBD_MAX_BUFFER_SIZE);
     /* preferred - Hard-code to 4096 for now.
      * TODO: is blk_bs(blk)->bl.opt_transfer appropriate? */
-    sizes[1] = 4096;
+    sizes[1] = MAX(4096, sizes[0]);
     /* maximum - At most 32M, but smaller as appropriate. */
     sizes[2] = MIN(blk_get_max_transfer(exp->blk), NBD_MAX_BUFFER_SIZE);
     trace_nbd_negotiate_handle_info_block_size(sizes[0], sizes[1], sizes[2]);
@@ -637,11 +646,14 @@ static int nbd_negotiate_handle_info(NBDClient *client, uint16_t myflags,
         return rc;
     }
 
-    /* If the client is just asking for NBD_OPT_INFO, but forgot to
-     * request block sizes, return an error.
-     * TODO: consult blk_bs(blk)->request_align, and only error if it
-     * is not 1? */
-    if (client->opt == NBD_OPT_INFO && !blocksize) {
+    /*
+     * If the client is just asking for NBD_OPT_INFO, but forgot to
+     * request block sizes in a situation that would impact
+     * performance, then return an error. But for NBD_OPT_GO, we
+     * tolerate all clients, regardless of alignments.
+     */
+    if (client->opt == NBD_OPT_INFO && !blocksize &&
+        blk_get_request_alignment(exp->blk) > 1) {
         return nbd_negotiate_send_rep_err(client,
                                           NBD_REP_ERR_BLOCK_SIZE_REQD,
                                           errp,
@@ -657,6 +669,7 @@ static int nbd_negotiate_handle_info(NBDClient *client, uint16_t myflags,
 
     if (client->opt == NBD_OPT_GO) {
         client->exp = exp;
+        client->check_align = check_align;
         QTAILQ_INSERT_TAIL(&client->exp->clients, client, next);
         nbd_export_get(client->exp);
         nbd_check_meta_export(client);
@@ -1474,13 +1487,15 @@ NBDExport *nbd_export_new(BlockDriverState *bs, uint64_t dev_offset,
     if ((nbdflags & NBD_FLAG_READ_ONLY) == 0) {
         perm |= BLK_PERM_WRITE;
     }
-    blk = blk_new(perm, BLK_PERM_CONSISTENT_READ | BLK_PERM_WRITE_UNCHANGED |
-                        BLK_PERM_WRITE | BLK_PERM_GRAPH_MOD);
+    blk = blk_new(bdrv_get_aio_context(bs), perm,
+                  BLK_PERM_CONSISTENT_READ | BLK_PERM_WRITE_UNCHANGED |
+                  BLK_PERM_WRITE | BLK_PERM_GRAPH_MOD);
     ret = blk_insert_bs(blk, bs, errp);
     if (ret < 0) {
         goto fail;
     }
     blk_set_enable_write_cache(blk, !writethrough);
+    blk_set_allow_aio_context_change(blk, true);
 
     exp->refcount = 1;
     QTAILQ_INIT(&exp->clients);
@@ -1877,17 +1892,12 @@ static int blockstatus_to_extents(BlockDriverState *bs, uint64_t offset,
 
         flags = (ret & BDRV_BLOCK_ALLOCATED ? 0 : NBD_STATE_HOLE) |
                 (ret & BDRV_BLOCK_ZERO      ? NBD_STATE_ZERO : 0);
-        offset += num;
-        remaining_bytes -= num;
 
         if (first_extent) {
             extent->flags = flags;
             extent->length = num;
             first_extent = false;
-            continue;
-        }
-
-        if (flags == extent->flags) {
+        } else if (flags == extent->flags) {
             /* extend current extent */
             extent->length += num;
         } else {
@@ -1900,6 +1910,8 @@ static int blockstatus_to_extents(BlockDriverState *bs, uint64_t offset,
             extent->flags = flags;
             extent->length = num;
         }
+        offset += num;
+        remaining_bytes -= num;
     }
 
     extents_end = extent + 1;
@@ -1951,7 +1963,7 @@ static int nbd_co_send_block_status(NBDClient *client, uint64_t handle,
                                     Error **errp)
 {
     int ret;
-    unsigned int nb_extents = dont_fragment ? 1 : NBD_MAX_BITMAP_EXTENTS;
+    unsigned int nb_extents = dont_fragment ? 1 : NBD_MAX_BLOCK_STATUS_EXTENTS;
     NBDExtent *extents = g_new(NBDExtent, nb_extents);
     uint64_t final_length = length;
 
@@ -2036,7 +2048,7 @@ static int nbd_co_send_bitmap(NBDClient *client, uint64_t handle,
                               uint32_t context_id, Error **errp)
 {
     int ret;
-    unsigned int nb_extents = dont_fragment ? 1 : NBD_MAX_BITMAP_EXTENTS;
+    unsigned int nb_extents = dont_fragment ? 1 : NBD_MAX_BLOCK_STATUS_EXTENTS;
     NBDExtent *extents = g_new(NBDExtent, nb_extents);
     uint64_t final_length = length;
 
@@ -2126,6 +2138,17 @@ static int nbd_co_receive_request(NBDRequestData *req, NBDRequest *request,
         return (request->type == NBD_CMD_WRITE ||
                 request->type == NBD_CMD_WRITE_ZEROES) ? -ENOSPC : -EINVAL;
     }
+    if (client->check_align && !QEMU_IS_ALIGNED(request->from | request->len,
+                                                client->check_align)) {
+        /*
+         * The block layer gracefully handles unaligned requests, but
+         * it's still worth tracing client non-compliance
+         */
+        trace_nbd_co_receive_align_compliance(nbd_cmd_lookup(request->type),
+                                              request->from,
+                                              request->len,
+                                              client->check_align);
+    }
     valid_flags = NBD_CMD_FLAG_FUA;
     if (request->type == NBD_CMD_READ && client->structured_reply) {
         valid_flags |= NBD_CMD_FLAG_DF;