From: Will Sowerbutts <will@sowerbutts.com>
Date: Sun, 11 Jan 2015 23:41:49 +0000 (+0000)
Subject: Kernel: d_flush() flushes the write cache of a device, using the private
X-Git-Url: https://git.ndcode.org/public/gitweb.cgi?a=commitdiff_plain;h=f4b220f4081fc1864fe1c668e166f5460e6bdd46;p=FUZIX.git

Kernel: d_flush() flushes the write cache of a device, using the private
device ioctl BLOCK_FLUSH_CACHE.

d_flush() is called on a device whenever a writable file is closed.
---

diff --git a/Kernel/devio.c b/Kernel/devio.c
index ce8d53da..0b0a7b0a 100644
--- a/Kernel/devio.c
+++ b/Kernel/devio.c
@@ -122,6 +122,7 @@ void bufsync(void)
 			bdwrite(bp);
 			if (!bp->bf_busy)
 				bp->bf_dirty = false;
+			d_flush(bp->bf_dev);
 		}
 	}
 }
@@ -283,6 +284,13 @@ int d_ioctl(uint16_t dev, uint16_t request, char *data)
 	return 0;
 }
 
+int d_flush(uint16_t dev)
+{
+	if (!validdev(dev))
+		panic("d_flush: bad device");
+	return (*dev_tab[major(dev)].dev_ioctl) (minor(dev), BLOCK_FLUSH_CACHE, 0);
+}
+
 /*
  *	No such device handler
  */
diff --git a/Kernel/include/kernel.h b/Kernel/include/kernel.h
index ff4388a1..eb3797fc 100644
--- a/Kernel/include/kernel.h
+++ b/Kernel/include/kernel.h
@@ -507,6 +507,7 @@ struct s_argblk {
  */
 #define SELECT_BEGIN		0x8000
 #define SELECT_END		0x8001
+#define BLOCK_FLUSH_CACHE       0x8002
 
 struct sysinfoblk {
   uint8_t infosize;		/* For expandability */
@@ -596,6 +597,7 @@ CODE1 int cdread(uint16_t dev, uint8_t flag);
 CODE1 int d_open(uint16_t dev, uint8_t flag);
 CODE1 int d_close(uint16_t dev);
 CODE1 int d_ioctl(uint16_t dev, uint16_t request, char *data);
+CODE1 int d_flush(uint16_t dev);
 CODE1 int cdwrite(uint16_t dev, uint8_t flag);
 CODE1 bool insq(struct s_queue *q, unsigned char c);
 CODE1 bool remq(struct s_queue *q, unsigned char *cp);
diff --git a/Kernel/inode.c b/Kernel/inode.c
index cc4318fd..2a7ca9aa 100644
--- a/Kernel/inode.c
+++ b/Kernel/inode.c
@@ -198,6 +198,7 @@ int16_t doclose(uint8_t uindex)
 {
 	int8_t oftindex;
 	inoptr ino;
+	uint16_t flush_dev = NO_DEVICE;
 
 	if (!(ino = getinode(uindex)))
 		return (-1);
@@ -207,8 +208,10 @@ int16_t doclose(uint8_t uindex)
 	if (ino->c_refs == 1 && of_tab[oftindex].o_refs == 1) {
 		if (isdevice(ino))
 			d_close((int) (ino->c_node.i_addr[0]));
+		if (getmode(ino) == F_REG && O_ACCMODE(of_tab[oftindex].o_access))
+			flush_dev = ino->c_dev;
 #ifdef CONFIG_NET
-		if (issocket(ino)
+		if (issocket(ino))
 			sock_close(ino);
 #endif
 	}
@@ -216,6 +219,10 @@ int16_t doclose(uint8_t uindex)
 	udata.u_cloexec &= ~(1 << uindex);
 	oft_deref(oftindex);
 
+	/* if we closed a file in write mode, flush the device's cache after inode has been deferenced */
+	if(flush_dev != NO_DEVICE)
+		d_flush(flush_dev);
+
 	return (0);
 }
 
diff --git a/Kernel/syscall_fs.c b/Kernel/syscall_fs.c
index a62c74e2..6ce0d2e2 100644
--- a/Kernel/syscall_fs.c
+++ b/Kernel/syscall_fs.c
@@ -87,6 +87,7 @@ int16_t _sync(void)
 		if (ino->c_refs > 0 && (ino->c_flags & CDIRTY)) {
 			wr_inode(ino);
 			ino->c_flags &= ~CDIRTY;
+			/* WRS: also call d_flush(ino->c_dev) here? */
 		}
 
         /* This now also indirectly does the superblocks as they