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

From: Theodore Tso
Date: Sat Feb 02 2008 - 11:21:28 EST


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);
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/