[PATCH 08/32] IGET: Stop autofs from using iget() and read_inode() [try #2]

David Howells
2007-10-04T16:00:42Z

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

Signed-off-by: David Howells <dhowells@redhat.com>
---

fs/autofs/autofs_i.h | 1 +
fs/autofs/inode.c | 27 ++++++++++++++++++---------
fs/autofs/root.c | 22 ++++++++++++++++++----
3 files changed, 37 insertions(+), 13 deletions(-)

diff --git a/fs/autofs/autofs_i.h b/fs/autofs/autofs_i.h
index 8b4cca3..901a3e6 100644
--- a/fs/autofs/autofs_i.h
+++ b/fs/autofs/autofs_i.h
@@ -150,6 +150,7 @@ extern const struct file_operations autofs_root_operations;

int autofs_fill_super(struct super_block *, void *, int);
void autofs_kill_sb(struct super_block *sb);
+struct inode *autofs_iget(struct super_block *, unsigned long);

/* Queue management functions */

diff --git a/fs/autofs/inode.c b/fs/autofs/inode.c
index e7204d7..fc6a15e 100644
--- a/fs/autofs/inode.c
+++ b/fs/autofs/inode.c
@@ -52,10 +52,7 @@ out_kill_sb:
kill_anon_super(sb);
}

-static void autofs_read_inode(struct inode *inode);
-
static const struct super_operations autofs_sops = {
- .read_inode = autofs_read_inode,
.statfs = simple_statfs,
};

@@ -164,7 +161,9 @@ int autofs_fill_super(struct super_block *s, void *data, int silent)
s->s_time_gran = 1;
sbi->sb = s;

- root_inode = iget(s, AUTOFS_ROOT_INO);
+ root_inode = autofs_iget(s, AUTOFS_ROOT_INO);
+ if (IS_ERR(root_inode))
+ goto fail_free;
root = d_alloc_root(root_inode);
pipe = NULL;

@@ -230,11 +229,17 @@ fail_unlock:
return -EINVAL;
}

-static void autofs_read_inode(struct inode *inode)
+struct inode *autofs_iget(struct super_block *sb, unsigned long ino)
{
- ino_t ino = inode->i_ino;
unsigned int n;
- struct autofs_sb_info *sbi = autofs_sbi(inode->i_sb);
+ struct autofs_sb_info *sbi = autofs_sbi(sb);
+ struct inode *inode;
+
+ inode = iget_locked(sb, ino);
+ if (!inode)
+ return ERR_PTR(-ENOMEM);
+ if (!(inode->i_state & I_NEW))
+ return inode;

/* Initialize to the default case (stub directory) */

@@ -250,7 +255,7 @@ static void autofs_read_inode(struct inode *inode)
inode->i_op = &autofs_root_inode_operations;
inode->i_fop = &autofs_root_operations;
inode->i_uid = inode->i_gid = 0; /* Changed in read_super */
- return;
+ goto done;
}

inode->i_uid = inode->i_sb->s_root->d_inode->i_uid;
@@ -263,7 +268,7 @@ static void autofs_read_inode(struct inode *inode)
n = ino - AUTOFS_FIRST_SYMLINK;
if (n >= AUTOFS_MAX_SYMLINKS || !test_bit(n,sbi->symlink_bitmap)) {
printk("autofs: Looking for bad symlink inode %u\n", (unsigned int) ino);
- return;
+ goto done;
}

inode->i_op = &autofs_symlink_inode_operations;
@@ -275,4 +280,8 @@ static void autofs_read_inode(struct inode *inode)
inode->i_size = sl->len;
inode->i_nlink = 1;
}
+
+done:
+ unlock_new_inode(inode);
+ return inode;
}
diff --git a/fs/autofs/root.c b/fs/autofs/root.c
index c148953..3aec567 100644
--- a/fs/autofs/root.c
+++ b/fs/autofs/root.c
@@ -114,8 +114,8 @@ static int try_to_fill_dentry(struct dentry *dentry, struct super_block *sb, str
dentry->d_time = (unsigned long) ent;

if (!dentry->d_inode) {
- inode = iget(sb, ent->ino);
- if (!inode) {
+ inode = autofs_iget(sb, ent->ino);
+ if (IS_ERR(inode)) {
/* Failed, but leave pending for next time */
return 1;
}
@@ -274,6 +274,7 @@ static int autofs_root_symlink(struct inode *dir, struct dentry *dentry, const c
unsigned int n;
int slsize;
struct autofs_symlink *sl;
+ struct inode *inode;

DPRINTK(("autofs_root_symlink: %s <- ", symname));
autofs_say(dentry->d_name.name,dentry->d_name.len);
@@ -331,7 +332,12 @@ static int autofs_root_symlink(struct inode *dir, struct dentry *dentry, const c
ent->dentry = NULL; /* We don't keep the dentry for symlinks */

autofs_hash_insert(dh,ent);
- d_instantiate(dentry, iget(dir->i_sb,ent->ino));
+
+ inode = autofs_iget(dir->i_sb, ent->ino);
+ if (IS_ERR(inode))
+ return PTR_ERR(inode);
+
+ d_instantiate(dentry, inode);
unlock_kernel();
return 0;
}
@@ -428,6 +434,7 @@ static int autofs_root_mkdir(struct inode *dir, struct dentry *dentry, int mode)
struct autofs_sb_info *sbi = autofs_sbi(dir->i_sb);
struct autofs_dirhash *dh = &sbi->dirhash;
struct autofs_dir_ent *ent;
+ struct inode *inode;
ino_t ino;

lock_kernel();
@@ -469,7 +476,14 @@ static int autofs_root_mkdir(struct inode *dir, struct dentry *dentry, int mode)
autofs_hash_insert(dh,ent);

inc_nlink(dir);
- d_instantiate(dentry, iget(dir->i_sb,ino));
+
+ inode = autofs_iget(dir->i_sb, ino);
+ if (IS_ERR(inode)) {
+ drop_nlink(dir);
+ return PTR_ERR(inode);
+ }
+
+ d_instantiate(dentry, inode);
unlock_kernel();

return 0;