Re: [PATCH] ext4: Replace use of iget() with iget_locked()

[Theodore Tso]

On Sat, Feb 02, 2008 at 10:55:24AM -0500, Theodore Ts'o wrote:
> In the mm tree is a patch queued up to nuke iget().  So replace use of
> iget() with iget_locked().  I will be pushing this to Linus shortly.

Oops, wrong version of the patch; this is the correct one.

      	    	       	   	       - Ted

ext4: Replace use of iget() with iget_locked()
    
Signed-off-by: "Theodore Ts'o" <tytso@xxxxxxx>

---
diff --git a/fs/ext4/ialloc.c b/fs/ext4/ialloc.c
index 575b521..d45fcaa 100644
--- a/fs/ext4/ialloc.c
+++ b/fs/ext4/ialloc.c
@@ -805,9 +805,17 @@ struct inode *ext4_orphan_get(struct super_block *sb, unsigned long ino)
 	 * is a valid orphan (no e2fsck run on fs).  Orphans also include
 	 * inodes that were being truncated, so we can't check i_nlink==0.
 	 */
-	if (!ext4_test_bit(bit, bitmap_bh->b_data) ||
-			!(inode = iget(sb, ino)) || is_bad_inode(inode) ||
-			NEXT_ORPHAN(inode) > max_ino) {
+	if (!ext4_test_bit(bit, bitmap_bh->b_data))
+		goto bad_orphan_inode;
+	inode = iget_locked(sb, ino);
+	if (!inode)
+		goto bad_orphan_inode;
+	if (inode->i_state & I_NEW) {
+		sb->s_op->read_inode(inode);
+		unlock_new_inode(inode);
+	}
+	if (is_bad_inode(inode) || NEXT_ORPHAN(inode) > max_ino) {
+	bad_orphan_inode:
 		ext4_warning(sb, __FUNCTION__,
 			     "bad orphan inode %lu!  e2fsck was run?", ino);
 		printk(KERN_NOTICE "ext4_test_bit(bit=%d, block=%llu) = %d\n",
diff --git a/fs/ext4/namei.c b/fs/ext4/namei.c
index 67b6d8a..57dd8fb 100644
--- a/fs/ext4/namei.c
+++ b/fs/ext4/namei.c
@@ -1041,11 +1041,16 @@ static struct dentry *ext4_lookup(struct inode * dir, struct dentry *dentry, str
 				   "bad inode number: %lu", ino);
 			inode = NULL;
 		} else
-			inode = iget(dir->i_sb, ino);
+			inode = iget_locked(dir->i_sb, ino);
 
 		if (!inode)
 			return ERR_PTR(-EACCES);
 
+		if (inode->i_state & I_NEW) {
+			inode->i_sb->s_op->read_inode(inode);
+			unlock_new_inode(inode);
+		}
+
 		if (is_bad_inode(inode)) {
 			iput(inode);
 			return ERR_PTR(-ENOENT);
@@ -1080,11 +1085,16 @@ struct dentry *ext4_get_parent(struct dentry *child)
 			   "bad inode number: %lu", ino);
 		inode = NULL;
 	} else
-		inode = iget(child->d_inode->i_sb, ino);
+		inode = iget_locked(child->d_inode->i_sb, ino);
 
 	if (!inode)
 		return ERR_PTR(-EACCES);
 
+	if (inode->i_state & I_NEW) {
+		inode->i_sb->s_op->read_inode(inode);
+		unlock_new_inode(inode);
+	}
+
 	if (is_bad_inode(inode)) {
 		iput(inode);
 		return ERR_PTR(-ENOENT);
diff --git a/fs/ext4/resize.c b/fs/ext4/resize.c
index 4fbba60..ebdca31 100644
--- a/fs/ext4/resize.c
+++ b/fs/ext4/resize.c
@@ -779,7 +779,11 @@ int ext4_group_add(struct super_block *sb, struct ext4_new_group_data *input)
 				     "No reserved GDT blocks, can't resize");
 			return -EPERM;
 		}
-		inode = iget(sb, EXT4_RESIZE_INO);
+		inode = iget_locked(sb, EXT4_RESIZE_INO);
+		if (inode && (inode->i_state & I_NEW)) {
+			sb->s_op->read_inode(inode);
+			unlock_new_inode(inode);
+		}
 		if (!inode || is_bad_inode(inode)) {
 			ext4_warning(sb, __FUNCTION__,
 				     "Error opening resize inode");
diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index 055a0cd..1ef0359 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -777,9 +777,13 @@ static struct inode *ext4_nfs_get_inode(struct super_block *sb,
 	 * Currently we don't know the generation for parent directory, so
 	 * a generation of 0 means "accept any"
 	 */
-	inode = iget(sb, ino);
+	inode = iget_locked(sb, ino);
 	if (inode == NULL)
 		return ERR_PTR(-ENOMEM);
+	if (inode->i_state & I_NEW) {
+		sb->s_op->read_inode(inode);
+		unlock_new_inode(inode);
+	}
 	if (is_bad_inode(inode) ||
 	    (generation && inode->i_generation != generation)) {
 		iput(inode);
@@ -2243,7 +2247,15 @@ static int ext4_fill_super (struct super_block *sb, void *data, int silent)
 	 * so we can safely mount the rest of the filesystem now.
 	 */
 
-	root = iget(sb, EXT4_ROOT_INO);
+	root = iget_locked(sb, EXT4_ROOT_INO);
+	if (!root) {
+		printk(KERN_ERR "EXT4-fs: iget_locked for root inode failed\n");
+		goto failed_mount4;
+	}
+	if (root->i_state & I_NEW) {
+		sb->s_op->read_inode(root);
+		unlock_new_inode(root);
+	}
 	sb->s_root = d_alloc_root(root);
 	if (!sb->s_root) {
 		printk(KERN_ERR "EXT4-fs: get root inode failed\n");
@@ -2372,11 +2384,15 @@ static journal_t *ext4_get_journal(struct super_block *sb,
 	 * things happen if we iget() an unused inode, as the subsequent
 	 * iput() will try to delete it. */
 
-	journal_inode = iget(sb, journal_inum);
+	journal_inode = iget_locked(sb, journal_inum);
 	if (!journal_inode) {
-		printk(KERN_ERR "EXT4-fs: no journal found.\n");
+		printk(KERN_ERR "EXT4-fs: iget_locked for journal inode failed.\n");
 		return NULL;
 	}
+	if (journal_inode->i_state & I_NEW) {
+		sb->s_op->read_inode(journal_inode);
+		unlock_new_inode(journal_inode);
+	}
 	if (!journal_inode->i_nlink) {
 		make_bad_inode(journal_inode);
 		iput(journal_inode);
--
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