[PATCH 13/30] IGET: Stop EXT4 from using iget() and read_inode()

From: David Howells
Date: Mon Oct 01 2007 - 09:15:04 EST


Stop the EXT4 filesystem from using iget() and read_inode(). Replace
ext4_read_inode() with ext4_iget(), and call that instead of iget().
ext4_iget() then uses iget_locked() directly and returns a proper error code
instead of an inode in the event of an error.

ext4_fill_super() returns any error incurred when getting the root inode
instead of EINVAL.

Signed-off-by: David Howells <dhowells@xxxxxxxxxx>
---

fs/ext4/ialloc.c | 13 +++++++++----
fs/ext4/inode.c | 25 +++++++++++++++++++------
fs/ext4/namei.c | 25 +++++++------------------
fs/ext4/resize.c | 7 +++----
fs/ext4/super.c | 36 ++++++++++++++++++++----------------
include/linux/ext4_fs.h | 2 +-
6 files changed, 59 insertions(+), 49 deletions(-)

diff --git a/fs/ext4/ialloc.c b/fs/ext4/ialloc.c
index 427f830..8bb63f2 100644
--- a/fs/ext4/ialloc.c
+++ b/fs/ext4/ialloc.c
@@ -682,9 +682,14 @@ 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 out;
+
+ inode = ext4_iget(sb, ino);
+ if (IS_ERR(inode))
+ goto out;
+
+ if (NEXT_ORPHAN(inode) > max_ino) {
ext4_warning(sb, __FUNCTION__,
"bad orphan inode %lu! e2fsck was run?", ino);
printk(KERN_NOTICE "ext4_test_bit(bit=%d, block=%llu) = %d\n",
@@ -702,7 +707,7 @@ struct inode *ext4_orphan_get(struct super_block *sb, unsigned long ino)
if (inode && inode->i_nlink == 0)
inode->i_blocks = 0;
iput(inode);
- inode = NULL;
+ inode = ERR_PTR(-EIO);
}
out:
brelse(bitmap_bh);
diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index a4848e0..c4fb1eb 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -2595,21 +2595,31 @@ void ext4_get_inode_flags(struct ext4_inode_info *ei)
ei->i_flags |= EXT4_DIRSYNC_FL;
}

-void ext4_read_inode(struct inode * inode)
+struct inode *ext4_iget(struct super_block *sb, unsigned long ino)
{
struct ext4_iloc iloc;
struct ext4_inode *raw_inode;
- struct ext4_inode_info *ei = EXT4_I(inode);
+ struct ext4_inode_info *ei;
struct buffer_head *bh;
+ struct inode *inode;
+ long ret;
int block;

+ inode = iget_locked(sb, ino);
+ if (!inode)
+ return ERR_PTR(-ENOMEM);
+ if (!(inode->i_state & I_NEW))
+ return inode;
+
+ ei = EXT4_I(inode);
#ifdef CONFIG_EXT4DEV_FS_POSIX_ACL
ei->i_acl = EXT4_ACL_NOT_CACHED;
ei->i_default_acl = EXT4_ACL_NOT_CACHED;
#endif
ei->i_block_alloc_info = NULL;

- if (__ext4_get_inode_loc(inode, &iloc, 0))
+ ret = __ext4_get_inode_loc(inode, &iloc, 0);
+ if (ret < 0)
goto bad_inode;
bh = iloc.bh;
raw_inode = ext4_raw_inode(&iloc);
@@ -2636,6 +2646,7 @@ void ext4_read_inode(struct inode * inode)
!(EXT4_SB(inode->i_sb)->s_mount_state & EXT4_ORPHAN_FS)) {
/* this inode is deleted */
brelse (bh);
+ ret = -ESTALE;
goto bad_inode;
}
/* The only unlinked inodes we let through here have
@@ -2683,6 +2694,7 @@ void ext4_read_inode(struct inode * inode)
if (EXT4_GOOD_OLD_INODE_SIZE + ei->i_extra_isize >
EXT4_INODE_SIZE(inode->i_sb)) {
brelse (bh);
+ ret = -EIO;
goto bad_inode;
}
if (ei->i_extra_isize == 0) {
@@ -2729,11 +2741,12 @@ void ext4_read_inode(struct inode * inode)
}
brelse (iloc.bh);
ext4_set_inode_flags(inode);
- return;
+ unlock_new_inode(inode);
+ return inode;

bad_inode:
- make_bad_inode(inode);
- return;
+ iget_failed(inode);
+ return ERR_PTR(ret);
}

/*
diff --git a/fs/ext4/namei.c b/fs/ext4/namei.c
index 5fdb862..af98d07 100644
--- a/fs/ext4/namei.c
+++ b/fs/ext4/namei.c
@@ -1044,17 +1044,11 @@ static struct dentry *ext4_lookup(struct inode * dir, struct dentry *dentry, str
if (!ext4_valid_inum(dir->i_sb, ino)) {
ext4_error(dir->i_sb, "ext4_lookup",
"bad inode number: %lu", ino);
- inode = NULL;
- } else
- inode = iget(dir->i_sb, ino);
-
- if (!inode)
return ERR_PTR(-EACCES);
-
- if (is_bad_inode(inode)) {
- iput(inode);
- return ERR_PTR(-ENOENT);
}
+ inode = ext4_iget(dir->i_sb, ino);
+ if (IS_ERR(inode))
+ return ERR_PTR(PTR_ERR(inode));
}
return d_splice_alias(inode, dentry);
}
@@ -1083,18 +1077,13 @@ struct dentry *ext4_get_parent(struct dentry *child)
if (!ext4_valid_inum(child->d_inode->i_sb, ino)) {
ext4_error(child->d_inode->i_sb, "ext4_get_parent",
"bad inode number: %lu", ino);
- inode = NULL;
- } else
- inode = iget(child->d_inode->i_sb, ino);
-
- if (!inode)
return ERR_PTR(-EACCES);
-
- if (is_bad_inode(inode)) {
- iput(inode);
- return ERR_PTR(-ENOENT);
}

+ inode = ext4_iget(child->d_inode->i_sb, ino);
+ if (IS_ERR(inode))
+ return ERR_PTR(PTR_ERR(inode));
+
parent = d_alloc_anon(inode);
if (!parent) {
iput(inode);
diff --git a/fs/ext4/resize.c b/fs/ext4/resize.c
index aa11d7d..345f901 100644
--- a/fs/ext4/resize.c
+++ b/fs/ext4/resize.c
@@ -757,12 +757,11 @@ 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);
- if (!inode || is_bad_inode(inode)) {
+ inode = ext4_iget(sb, EXT4_RESIZE_INO);
+ if (IS_ERR(inode)) {
ext4_warning(sb, __FUNCTION__,
"Error opening resize inode");
- iput(inode);
- return -ENOENT;
+ return PTR_ERR(inode);
}
}

diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index 3c1397f..74bbbe0 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -634,11 +634,10 @@ static struct dentry *ext4_get_dentry(struct super_block *sb, void *vobjp)
* Currently we don't know the generation for parent directory, so
* a generation of 0 means "accept any"
*/
- inode = iget(sb, ino);
- if (inode == NULL)
- return ERR_PTR(-ENOMEM);
- if (is_bad_inode(inode) ||
- (generation && inode->i_generation != generation)) {
+ inode = ext4_iget(sb, ino);
+ if (IS_ERR(inode))
+ return ERR_PTR(PTR_ERR(inode));
+ if (generation && inode->i_generation != generation) {
iput(inode);
return ERR_PTR(-ESTALE);
}
@@ -700,7 +699,6 @@ static struct quotactl_ops ext4_qctl_operations = {
static const struct super_operations ext4_sops = {
.alloc_inode = ext4_alloc_inode,
.destroy_inode = ext4_destroy_inode,
- .read_inode = ext4_read_inode,
.write_inode = ext4_write_inode,
.dirty_inode = ext4_dirty_inode,
.delete_inode = ext4_delete_inode,
@@ -1472,6 +1470,7 @@ static int ext4_fill_super (struct super_block *sb, void *data, int silent)
unsigned long journal_devnum = 0;
unsigned long def_mount_opts;
struct inode *root;
+ int ret = -EINVAL;
int blocksize;
int hblock;
int db_count;
@@ -1862,19 +1861,24 @@ 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);
- sb->s_root = d_alloc_root(root);
- if (!sb->s_root) {
+ root = ext4_iget(sb, EXT4_ROOT_INO);
+ if (IS_ERR(root)) {
printk(KERN_ERR "EXT4-fs: get root inode failed\n");
- iput(root);
+ ret = PTR_ERR(root);
goto failed_mount4;
}
if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
- dput(sb->s_root);
- sb->s_root = NULL;
+ iput(root);
printk(KERN_ERR "EXT4-fs: corrupt root inode, run e2fsck\n");
goto failed_mount4;
}
+ sb->s_root = d_alloc_root(root);
+ if (!sb->s_root) {
+ printk(KERN_ERR "EXT4-fs: get root dentry failed\n");
+ iput(root);
+ ret = -ENOMEM;
+ goto failed_mount4;
+ }

ext4_setup_super (sb, es, sb->s_flags & MS_RDONLY);

@@ -1954,7 +1958,7 @@ out_fail:
sb->s_fs_info = NULL;
kfree(sbi);
lock_kernel();
- return -EINVAL;
+ return ret;
}

/*
@@ -1990,8 +1994,8 @@ 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);
- if (!journal_inode) {
+ journal_inode = ext4_iget(sb, journal_inum);
+ if (IS_ERR(journal_inode)) {
printk(KERN_ERR "EXT4-fs: no journal found.\n");
return NULL;
}
@@ -2004,7 +2008,7 @@ static journal_t *ext4_get_journal(struct super_block *sb,

jbd_debug(2, "Journal inode found at %p: %Ld bytes\n",
journal_inode, journal_inode->i_size);
- if (is_bad_inode(journal_inode) || !S_ISREG(journal_inode->i_mode)) {
+ if (!S_ISREG(journal_inode->i_mode)) {
printk(KERN_ERR "EXT4-fs: invalid journal inode.\n");
iput(journal_inode);
return NULL;
diff --git a/include/linux/ext4_fs.h b/include/linux/ext4_fs.h
index cdee7aa..12354d5 100644
--- a/include/linux/ext4_fs.h
+++ b/include/linux/ext4_fs.h
@@ -944,7 +944,7 @@ int ext4_get_blocks_handle(handle_t *handle, struct inode *inode,
sector_t iblock, unsigned long maxblocks, struct buffer_head *bh_result,
int create, int extend_disksize);

-extern void ext4_read_inode (struct inode *);
+extern struct inode *ext4_iget(struct super_block *, unsigned long);
extern int ext4_write_inode (struct inode *, int);
extern int ext4_setattr (struct dentry *, struct iattr *);
extern void ext4_delete_inode (struct inode *);

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