log write() data

usertest for big write()s
push begin_trans/commit_trans down into syscalls

1 files changed, 26 insertions, 3 deletions

diff --git a/file.c b/file.c
index e10b824..7101a50 100644
--- a/file.c
+++ b/file.c
@@ -67,8 +67,11 @@ fileclose(struct file *f)
   
   if(ff.type == FD_PIPE)
     pipeclose(ff.pipe, ff.writable);
-  else if(ff.type == FD_INODE)
+  else if(ff.type == FD_INODE){
+    begin_trans();
     iput(ff.ip);
+    commit_trans();
+  }
 }
 
 // Get metadata about file f.
@@ -116,10 +119,30 @@ filewrite(struct file *f, char *addr, int n)
     return pipewrite(f->pipe, addr, n);
   if(f->type == FD_INODE){
     ilock(f->ip);
-    if((r = writei(f->ip, addr, f->off, n)) > 0)
+    // write a few blocks at a time to avoid exceeding
+    // the maximum log transaction size, including
+    // i-node, indirect block, allocation blocks,
+    // and 2 blocks of slop for non-aligned writes.
+    // this really belongs lower down, since writei()
+    // might be writing a device like the console.
+    int max = ((LOGSIZE-1-1-2) / 2) * 512;
+    int i = 0;
+    while(i < n){
+      int n1 = n - i;
+      if(n1 > max)
+        n1 = max;
+      begin_trans();
+      r = writei(f->ip, addr + i, f->off, n1);
+      commit_trans();
+      if(r < 0)
+        break;
+      if(r != n1)
+        panic("short filewrite");
       f->off += r;
+      i += r;
+    }
     iunlock(f->ip);
-    return r;
+    return i == n ? n : -1;
   }
   panic("filewrite");
 }