From 2ceecf6128022eddf6bca6e0e8966819b2893310 Mon Sep 17 00:00:00 2001
From: wangdi <wangdi>
Date: Fri, 16 Jan 2004 13:03:05 +0000
Subject: [PATCH] update snapfs 1)add mntget and mntput for snap_current when
 mount snap_clone 2)get rid of bmap in currentfs_write and fix some bug in it
 3)some minor fix

---
 lustre/snapfs/clonefs.c         |  2 ++
 lustre/snapfs/file.c            | 73 +++++++++++++++++++++--------------------
 lustre/snapfs/psdev.c           |  2 --
 lustre/snapfs/snapfs_internal.h |  5 ++-
 lustre/snapfs/super.c           | 38 +++++++++++++++++++++
 lustre/snapfs/sysctl.c          |  5 +--
 6 files changed, 84 insertions(+), 41 deletions(-)

diff --git a/lustre/snapfs/clonefs.c b/lustre/snapfs/clonefs.c
index 71a0735..b4f136c 100644
--- a/lustre/snapfs/clonefs.c
+++ b/lustre/snapfs/clonefs.c
@@ -142,6 +142,8 @@ static void clonefs_put_super(struct super_block *sb)
 	clone_sb = (struct snap_clone_info *)&sb->u.generic_sbp;
 	dput(clone_sb->clone_cache->cache_sb->s_root);
 	list_del(&clone_sb->clone_list_entry);
+	
+	put_snap_current_mnt(clone_sb->clone_cache->cache_sb);
 
 	EXIT;
 }
diff --git a/lustre/snapfs/file.c b/lustre/snapfs/file.c
index 78cc9ab..dee3eaa 100644
--- a/lustre/snapfs/file.c
+++ b/lustre/snapfs/file.c
@@ -41,22 +41,20 @@ static void currentfs_restore_snapfile(struct inode *cache_inode,
         cache_file->f_pos = clone_file->f_pos;
 }
 
-
 static ssize_t currentfs_write (struct file *filp, const char *buf, 
 				size_t count, loff_t *ppos)
 {
         struct snap_cache *cache;
 	struct inode *inode = filp->f_dentry->d_inode;
-        ssize_t rc;
         struct file_operations *fops;
-	loff_t pos;
-	long block[2]={-1,-1}, mask, i;
+	long block[2]={-1,-1};
 	struct snap_table *table;
-	int slot = 0;
-	int index = 0;
-	struct address_space_operations *aops;
 	struct inode *cache_inode = NULL;
 	struct snapshot_operations *snapops;
+	int slot = 0, index = 0, result = 0;
+	long mask, i;
+        ssize_t rc;
+	loff_t pos;
   
 	ENTRY;
 
@@ -96,36 +94,42 @@ static ssize_t currentfs_write (struct file *filp, const char *buf,
 	if( block[0] == block[1] )
 		block[1] = -1;
 	
-	aops = filter_c2cfaops(cache->cache_filter);
 	snapops = filter_c2csnapops(cache->cache_filter);
 
-	for( i=0; i<2; i++ ){
-		if(block[i]!=-1 && aops->bmap(inode->i_mapping, block[i])) {
-			table = &snap_tables[cache->cache_snap_tableno];
-        		for (slot = table->tbl_count - 1; slot >= 1; slot--) {
-				struct address_space_operations *c_aops = 
-					cache_inode->i_mapping->a_ops;
-				cache_inode = NULL;
-                		index = table->snap_items[slot].index;
-				cache_inode = snap_get_indirect(inode, NULL, index);
-
-				if ( !cache_inode )  continue;
-
-	                	if (c_aops->bmap(cache_inode->i_mapping, block[i])) {
-					CDEBUG(D_SNAP, "find cache_ino %lu\n",
-						cache_inode->i_ino);
-					if( snapops && snapops->copy_block) {
-						snapops->copy_block(inode, 
-								cache_inode, block[i]);
-					}
+	for (i = 0; i < 2; i++) {
+		if (block[i] == -1) 
+			continue;
+		table = &snap_tables[cache->cache_snap_tableno];
+		/*Find the nearest block in snaptable and copy back it*/
+		for (slot = table->tbl_count - 1; slot >= 1; slot--) {
+			cache_inode = NULL;
+               		index = table->snap_items[slot].index;
+			cache_inode = snap_get_indirect(inode, NULL, index);
+
+			if (!cache_inode)  continue;
+
+			CDEBUG(D_SNAP, "find cache_ino %lu\n", cache_inode->i_ino);
+		
+			if (snapops && snapops->copy_block) {
+				result = snapops->copy_block(inode, cache_inode, block[i]);
+				if (result == 1) {
+					CDEBUG(D_SNAP, "copy block %lu back from ind %lu to %lu\n", 
+					       block[i], cache_inode->i_ino, inode->i_ino);
+               				iput(cache_inode);
+					result = 0;
+					break;
+				}
+				if (result < 0) {
 					iput(cache_inode);
-                        		break;
-                		}
-                       		iput(cache_inode);
-        		}
-		}
+					rc = result;
+					goto exit;
+				}
+			}
+               		iput(cache_inode);
+        	}
 	}
         rc = fops->write(filp, buf, count, ppos);
+exit:
         RETURN(rc);
 }
 
@@ -179,10 +183,7 @@ static int currentfs_readpage(struct file *file, struct page *page)
 
 	table = &snap_tables[cache->cache_snap_tableno];
 
-        for (slot = table->tbl_count - 1; slot >= 1; slot--)
-        {
-		struct address_space_operations *c_aops = 
-					cache_inode->i_mapping->a_ops;
+        for (slot = table->tbl_count - 1; slot >= 1; slot--) {
 		cache_inode = NULL;
                 index = table->snap_items[slot].index;
 		cache_inode = snap_get_indirect(inode, NULL, index);
diff --git a/lustre/snapfs/psdev.c b/lustre/snapfs/psdev.c
index 764adcc..33b7608 100644
--- a/lustre/snapfs/psdev.c
+++ b/lustre/snapfs/psdev.c
@@ -29,8 +29,6 @@
 #include "snapfs_internal.h" 
 
 
-int snap_print_entry = 1;
-int snap_debug_level = 0;
 int snap_inodes = 0;
 long snap_kmemory = 0;
 int snap_stack = 0;
diff --git a/lustre/snapfs/snapfs_internal.h b/lustre/snapfs/snapfs_internal.h
index 1ac04d7..6ce3e3e 100644
--- a/lustre/snapfs/snapfs_internal.h
+++ b/lustre/snapfs/snapfs_internal.h
@@ -278,6 +278,9 @@ int snap_migrate_data(struct inode *dst, struct inode *src);
 int snap_set_indirect(struct inode *pri, ino_t ind_ino, 
 			int index, ino_t parent_ino);
 
+/*super.c */
+void put_snap_current_mnt(struct super_block *sb);
+void get_snap_current_mnt(struct super_block *sb);
 /* inode.c */
 extern struct super_operations currentfs_super_ops;
 void cleanup_filter_info_cache(void);
@@ -403,7 +406,7 @@ static inline void snapfs_cpy_attrs(struct inode *dst, struct inode *src)
 	dst->i_gid = src->i_gid;
 	dst->i_mode = src->i_mode;
 }
-#ifdef SNAP_DEBUG
+#if 0
 extern unsigned int snap_debug_failcode;
 #ifdef CONFIG_LOOP_DISCARD
 #define BLKDEV_FAIL(dev,fail) loop_discard_io(dev,fail)
diff --git a/lustre/snapfs/super.c b/lustre/snapfs/super.c
index 587075b..bfeecde 100644
--- a/lustre/snapfs/super.c
+++ b/lustre/snapfs/super.c
@@ -44,6 +44,42 @@ static void put_filesystem(struct file_system_type *fs)
 		__MOD_DEC_USE_COUNT(fs->owner);
 }
 
+static struct vfsmount* get_vfsmount(struct super_block *sb)
+{
+	struct vfsmount	*rootmnt, *mnt, *ret = NULL;
+	struct list_head *end, *list;
+
+	rootmnt = mntget(current->fs->rootmnt);
+	end = list = &rootmnt->mnt_list;
+	do {
+		mnt = list_entry(list, struct vfsmount, mnt_list);
+		if (mnt->mnt_sb == sb) {
+			ret = mnt;
+			break;
+		}
+		list = list->next;
+	} while (end != list);
+	mntput(current->fs->rootmnt);
+	return ret;
+}
+
+void get_snap_current_mnt(struct super_block *sb)
+{
+	struct vfsmount *mnt;
+
+	mnt = get_vfsmount(sb);
+	if (mnt) 
+		mntget(mnt);
+}
+void put_snap_current_mnt(struct super_block *sb)
+{
+	struct vfsmount *mnt;
+
+	mnt = get_vfsmount(sb);
+	if (mnt) 
+		mntput(mnt);
+}
+
 /* In get_opt we get options in opt, value in opt_value
  * we must remember to free opt and opt_value*/
 static char * snapfs_options(char *options, char **cache_type, 
@@ -423,6 +459,8 @@ clone_read_super(
 
 	CDEBUG(D_SUPER, "sb %lx, &sb->u.generic_sbp: %lx\n",
                 (ulong) sb, (ulong) &sb->u.generic_sbp);
+ 	
+	get_snap_current_mnt(snap_cache->cache_sb);
  out_err:
 	cleanup_option();
 	if (err)
diff --git a/lustre/snapfs/sysctl.c b/lustre/snapfs/sysctl.c
index 1969081..b9d40d6 100644
--- a/lustre/snapfs/sysctl.c
+++ b/lustre/snapfs/sysctl.c
@@ -40,12 +40,13 @@ static struct ctl_table_header *snapfs_table_header = NULL;
 /* These are global control options */
 #define ENTRY_CNT 3
 
+int snap_print_entry = 1;
+int snap_debug_level = 0;
+
 /* XXX - doesn't seem to be working in 2.2.15 */
 static struct ctl_table snapfs_ctltable[] =
 {
-#ifdef SNAP_DEBUG
 	{PSDEV_DEBUG, "debug", &snap_debug_level, sizeof(int), 0644, NULL, &proc_dointvec},
-#endif
 	{PSDEV_TRACE, "trace", &snap_print_entry, sizeof(int), 0644, NULL, &proc_dointvec},
 	{0}
 };
-- 
1.8.3.1