Fix common misspellings

Fixes generated by 'codespell' and manually reviewed.

Signed-off-by: Lucas De Marchi <lucas.demarchi@profusion.mobi>
diff --git a/fs/jbd/commit.c b/fs/jbd/commit.c
index da871ee..69b1804 100644
--- a/fs/jbd/commit.c
+++ b/fs/jbd/commit.c
@@ -362,7 +362,7 @@
 	 * we do not require it to remember exactly which old buffers it
 	 * has reserved.  This is consistent with the existing behaviour
 	 * that multiple journal_get_write_access() calls to the same
-	 * buffer are perfectly permissable.
+	 * buffer are perfectly permissible.
 	 */
 	while (commit_transaction->t_reserved_list) {
 		jh = commit_transaction->t_reserved_list;
diff --git a/fs/jbd/journal.c b/fs/jbd/journal.c
index eb11601..b3713af 100644
--- a/fs/jbd/journal.c
+++ b/fs/jbd/journal.c
@@ -770,7 +770,7 @@
 	journal->j_wbufsize = n;
 	journal->j_wbuf = kmalloc(n * sizeof(struct buffer_head*), GFP_KERNEL);
 	if (!journal->j_wbuf) {
-		printk(KERN_ERR "%s: Cant allocate bhs for commit thread\n",
+		printk(KERN_ERR "%s: Can't allocate bhs for commit thread\n",
 			__func__);
 		goto out_err;
 	}
@@ -831,7 +831,7 @@
 	journal->j_wbufsize = n;
 	journal->j_wbuf = kmalloc(n * sizeof(struct buffer_head*), GFP_KERNEL);
 	if (!journal->j_wbuf) {
-		printk(KERN_ERR "%s: Cant allocate bhs for commit thread\n",
+		printk(KERN_ERR "%s: Can't allocate bhs for commit thread\n",
 			__func__);
 		goto out_err;
 	}
diff --git a/fs/jbd/revoke.c b/fs/jbd/revoke.c
index d290183..305a907 100644
--- a/fs/jbd/revoke.c
+++ b/fs/jbd/revoke.c
@@ -71,7 +71,7 @@
  * switching hash tables under them. For operations on the lists of entries in
  * the hash table j_revoke_lock is used.
  *
- * Finally, also replay code uses the hash tables but at this moment noone else
+ * Finally, also replay code uses the hash tables but at this moment no one else
  * can touch them (filesystem isn't mounted yet) and hence no locking is
  * needed.
  */
diff --git a/fs/jbd/transaction.c b/fs/jbd/transaction.c
index 5b2e4c3..60d2319 100644
--- a/fs/jbd/transaction.c
+++ b/fs/jbd/transaction.c
@@ -1392,7 +1392,7 @@
 	 * by 30x or more...
 	 *
 	 * We try and optimize the sleep time against what the underlying disk
-	 * can do, instead of having a static sleep time.  This is usefull for
+	 * can do, instead of having a static sleep time.  This is useful for
 	 * the case where our storage is so fast that it is more optimal to go
 	 * ahead and force a flush and wait for the transaction to be committed
 	 * than it is to wait for an arbitrary amount of time for new writers to