deadlock between spa_errlog_lock and dp_config_rwlock

[mirror_zfs.git] / lib / libzfs / libzfs_pool.c

diff --git a/lib/libzfs/libzfs_pool.c b/lib/libzfs/libzfs_pool.c
index 7f7e19a090bc5d32d39614d7dc0b5a42f7582a7c..2977986e1e6f4001722ff2961283a610119d334f 100644 (file)
--- a/lib/libzfs/libzfs_pool.c
+++ b/lib/libzfs/libzfs_pool.c
@@ -4133,33 +4133,28 @@ zpool_get_errlog(zpool_handle_t *zhp, nvlist_t **nverrlistp)
 {
        zfs_cmd_t zc = {"\0"};
        libzfs_handle_t *hdl = zhp->zpool_hdl;
-       uint64_t count;
-       zbookmark_phys_t *zb = NULL;
-       int i;
+       zbookmark_phys_t *buf;
+       uint64_t buflen = 10000; /* approx. 1MB of RAM */
+
+       if (fnvlist_lookup_uint64(zhp->zpool_config,
+           ZPOOL_CONFIG_ERRCOUNT) == 0)
+               return (0);
 
        /*
-        * Retrieve the raw error list from the kernel.  If the number of errors
-        * has increased, allocate more space and continue until we get the
-        * entire list.
+        * Retrieve the raw error list from the kernel.  If it doesn't fit,
+        * allocate a larger buffer and retry.
         */
-       count = fnvlist_lookup_uint64(zhp->zpool_config, ZPOOL_CONFIG_ERRCOUNT);
-       if (count == 0)
-               return (0);
-       zc.zc_nvlist_dst = (uintptr_t)zfs_alloc(zhp->zpool_hdl,
-           count * sizeof (zbookmark_phys_t));
-       zc.zc_nvlist_dst_size = count;
        (void) strcpy(zc.zc_name, zhp->zpool_name);
        for (;;) {
+               buf = zfs_alloc(zhp->zpool_hdl,
+                   buflen * sizeof (zbookmark_phys_t));
+               zc.zc_nvlist_dst = (uintptr_t)buf;
+               zc.zc_nvlist_dst_size = buflen;
                if (zfs_ioctl(zhp->zpool_hdl, ZFS_IOC_ERROR_LOG,
                    &zc) != 0) {
-                       free((void *)(uintptr_t)zc.zc_nvlist_dst);
+                       free(buf);
                        if (errno == ENOMEM) {
-                               void *dst;
-
-                               count = zc.zc_nvlist_dst_size;
-                               dst = zfs_alloc(zhp->zpool_hdl, count *
-                                   sizeof (zbookmark_phys_t));
-                               zc.zc_nvlist_dst = (uintptr_t)dst;
+                               buflen *= 2;
                        } else {
                                return (zpool_standard_error_fmt(hdl, errno,
                                    dgettext(TEXT_DOMAIN, "errors: List of "
@@ -4177,18 +4172,17 @@ zpool_get_errlog(zpool_handle_t *zhp, nvlist_t **nverrlistp)
         * _not_ copied as part of the process.  So we point the start of our
         * array appropriate and decrement the total number of elements.
         */
-       zb = ((zbookmark_phys_t *)(uintptr_t)zc.zc_nvlist_dst) +
-           zc.zc_nvlist_dst_size;
-       count -= zc.zc_nvlist_dst_size;
+       zbookmark_phys_t *zb = buf + zc.zc_nvlist_dst_size;
+       uint64_t zblen = buflen - zc.zc_nvlist_dst_size;
 
-       qsort(zb, count, sizeof (zbookmark_phys_t), zbookmark_mem_compare);
+       qsort(zb, zblen, sizeof (zbookmark_phys_t), zbookmark_mem_compare);
 
        verify(nvlist_alloc(nverrlistp, 0, KM_SLEEP) == 0);
 
        /*
         * Fill in the nverrlistp with nvlist's of dataset and object numbers.
         */
-       for (i = 0; i < count; i++) {
+       for (uint64_t i = 0; i < zblen; i++) {
                nvlist_t *nv;
 
                /* ignoring zb_blkid and zb_level for now */
@@ -4215,11 +4209,11 @@ zpool_get_errlog(zpool_handle_t *zhp, nvlist_t **nverrlistp)
                nvlist_free(nv);
        }
 
-       free((void *)(uintptr_t)zc.zc_nvlist_dst);
+       free(buf);
        return (0);
 
 nomem:
-       free((void *)(uintptr_t)zc.zc_nvlist_dst);
+       free(buf);
        return (no_memory(zhp->zpool_hdl));
 }