add directory kernel

kernel/0.95/linux-0.95/fs/inode.c

@@ -0,0 +1,246 @@
+/*
+ *  linux/fs/inode.c
+ *
+ *  (C) 1991  Linus Torvalds
+ */
+
+#include <string.h>
+#include <sys/stat.h>
+
+#include <linux/sched.h>
+#include <linux/minix_fs.h>
+#include <linux/kernel.h>
+#include <linux/mm.h>
+#include <asm/system.h>
+
+struct inode inode_table[NR_INODE]={{0,},};
+
+extern void minix_read_inode(struct inode * inode);
+extern void minix_write_inode(struct inode * inode);
+
+static inline void wait_on_inode(struct inode * inode)
+{
+	cli();
+	while (inode->i_lock)
+		sleep_on(&inode->i_wait);
+	sti();
+}
+
+static inline void lock_inode(struct inode * inode)
+{
+	cli();
+	while (inode->i_lock)
+		sleep_on(&inode->i_wait);
+	inode->i_lock=1;
+	sti();
+}
+
+static inline void unlock_inode(struct inode * inode)
+{
+	inode->i_lock=0;
+	wake_up(&inode->i_wait);
+}
+
+static void write_inode(struct inode * inode)
+{
+	lock_inode(inode);
+	if (!inode->i_dirt || !inode->i_dev) {
+		unlock_inode(inode);
+		return;
+	}
+	minix_write_inode(inode);
+	unlock_inode(inode);
+}
+
+static void read_inode(struct inode * inode)
+{
+	lock_inode(inode);
+	minix_read_inode(inode);
+	unlock_inode(inode);
+}
+
+int bmap(struct inode * inode, int block)
+{
+	return minix_bmap(inode,block);
+}
+
+void invalidate_inodes(int dev)
+{
+	int i;
+	struct inode * inode;
+
+	inode = 0+inode_table;
+	for(i=0 ; i<NR_INODE ; i++,inode++) {
+		wait_on_inode(inode);
+		if (inode->i_dev == dev) {
+			if (inode->i_count)
+				printk("inode in use on removed disk\n\r");
+			inode->i_dev = inode->i_dirt = 0;
+		}
+	}
+}
+
+void sync_inodes(void)
+{
+	int i;
+	struct inode * inode;
+
+	inode = 0+inode_table;
+	for(i=0 ; i<NR_INODE ; i++,inode++) {
+		wait_on_inode(inode);
+		if (inode->i_dirt && !inode->i_pipe)
+			write_inode(inode);
+	}
+}
+
+void iput(struct inode * inode)
+{
+	if (!inode)
+		return;
+	wait_on_inode(inode);
+	if (!inode->i_count)
+		panic("iput: trying to free free inode");
+	if (inode->i_pipe) {
+		wake_up(&inode->i_wait);
+		wake_up(&inode->i_wait2);
+		if (--inode->i_count)
+			return;
+		free_page(inode->i_size);
+		inode->i_count=0;
+		inode->i_dirt=0;
+		inode->i_pipe=0;
+		return;
+	}
+	if (!inode->i_dev) {
+		inode->i_count--;
+		return;
+	}
+	if (S_ISBLK(inode->i_mode)) {
+		sync_dev(inode->i_rdev);
+		wait_on_inode(inode);
+	}
+repeat:
+	if (inode->i_count>1) {
+		inode->i_count--;
+		return;
+	}
+	if (!inode->i_nlink) {
+		minix_truncate(inode);
+		minix_free_inode(inode);
+		return;
+	}
+	if (inode->i_dirt) {
+		write_inode(inode);	/* we can sleep - so do again */
+		wait_on_inode(inode);
+		goto repeat;
+	}
+	inode->i_count--;
+	return;
+}
+
+struct inode * get_empty_inode(void)
+{
+	struct inode * inode;
+	static struct inode * last_inode = inode_table;
+	int i;
+
+	do {
+		inode = NULL;
+		for (i = NR_INODE; i ; i--) {
+			if (++last_inode >= inode_table + NR_INODE)
+				last_inode = inode_table;
+			if (!last_inode->i_count) {
+				inode = last_inode;
+				if (!inode->i_dirt && !inode->i_lock)
+					break;
+			}
+		}
+		if (!inode) {
+			for (i=0 ; i<NR_INODE ; i++)
+				printk("(%04x: %d (%o)) ",inode_table[i].i_dev,
+					inode_table[i].i_ino,inode_table[i].i_mode);
+			panic("No free inodes in mem");
+		}
+		wait_on_inode(inode);
+		while (inode->i_dirt) {
+			write_inode(inode);
+			wait_on_inode(inode);
+		}
+	} while (inode->i_count);
+	memset(inode,0,sizeof(*inode));
+	inode->i_count = 1;
+	return inode;
+}
+
+struct inode * get_pipe_inode(void)
+{
+	struct inode * inode;
+
+	if (!(inode = get_empty_inode()))
+		return NULL;
+	if (!(inode->i_size=get_free_page())) {
+		inode->i_count = 0;
+		return NULL;
+	}
+	inode->i_count = 2;	/* sum of readers/writers */
+	PIPE_HEAD(*inode) = PIPE_TAIL(*inode) = 0;
+	inode->i_pipe = 1;
+	return inode;
+}
+
+struct inode * iget(int dev,int nr)
+{
+	struct inode * inode, * empty;
+
+	if (!dev)
+		panic("iget with dev==0");
+	empty = get_empty_inode();
+	inode = inode_table;
+	while (inode < NR_INODE+inode_table) {
+		if (inode->i_dev != dev || inode->i_ino != nr) {
+			inode++;
+			continue;
+		}
+		wait_on_inode(inode);
+		if (inode->i_dev != dev || inode->i_ino != nr) {
+			inode = inode_table;
+			continue;
+		}
+		inode->i_count++;
+		if (inode->i_mount) {
+			int i;
+
+			for (i = 0 ; i<NR_SUPER ; i++)
+				if (super_block[i].s_covered==inode)
+					break;
+			if (i >= NR_SUPER) {
+				printk("Mounted inode hasn't got sb\n");
+				if (empty)
+					iput(empty);
+				return inode;
+			}
+			iput(inode);
+			if (!(inode = super_block[i].s_mounted))
+				printk("iget: mounted dev has no rootinode\n");
+			else {
+				inode->i_count++;
+				wait_on_inode(inode);
+			}
+		}
+		if (empty)
+			iput(empty);
+		return inode;
+	}
+	if (!empty)
+		return (NULL);
+	inode = empty;
+	if (!(inode->i_sb = get_super(dev))) {
+		printk("iget: gouldn't get super-block\n\t");
+		iput(inode);
+		return NULL;
+	}
+	inode->i_dev = dev;
+	inode->i_ino = nr;
+	read_inode(inode);
+	return inode;
+}