Messages in this thread | | | Date | Thu, 4 May 2006 17:37:54 +0300 | From | "Pekka Enberg" <> | Subject | Re: [PATCH 6/13: eCryptfs] Superblock operations |
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Hi Phillip,
Some comments below.
On 5/4/06, Phillip Hellewell <phillip@hellewell.homeip.net> wrote: > +kmem_cache_t *ecryptfs_inode_info_cache;
Please use struct kmem_cache instead of the typedef.
> +static struct inode *ecryptfs_alloc_inode(struct super_block *sb) {
Formatting
> + struct ecryptfs_inode_info *ecryptfs_inode = NULL;
Redundant initialization
> + struct inode *inode = NULL; > + > + ecryptfs_printk(KERN_DEBUG, "Enter; sb = [%p]\n", sb); > + ecryptfs_inode = kmem_cache_alloc(ecryptfs_inode_info_cache, > + SLAB_KERNEL); > + if (unlikely(!ecryptfs_inode)) { > + ecryptfs_printk(KERN_WARNING, > + "Failed to allocate new inode\n"); > + goto out;
No need to log it, just return NULL here
> + } > + ecryptfs_init_crypt_stat(&(ecryptfs_inode->crypt_stat)); > + inode = &(ecryptfs_inode->vfs_inode);
Bogus parenthesis, twice. Inode is a redundant local variable, btw.
> +out: > + ecryptfs_printk(KERN_DEBUG, "Exit; inode = [%p]\n", inode); > + return inode; > +} > + > +/** > + * This is used during the final destruction of the inode. > + * All allocation of memory related to the inode, including allocated > + * memory in the crypt_stat struct, will be released here. > + * There should be no chance that this deallocation will be missed. > + */ > +static void ecryptfs_destroy_inode(struct inode *inode) {
Formatting
> + struct ecryptfs_crypt_stat *crypt_stat; > + > + ecryptfs_printk(KERN_DEBUG, "Enter; inode = [%p]\n", inode); > + crypt_stat = &(ECRYPTFS_INODE_TO_PRIVATE(inode))->crypt_stat; > + ecryptfs_destruct_crypt_stat(crypt_stat); > + kmem_cache_free(ecryptfs_inode_info_cache, > + ECRYPTFS_INODE_TO_PRIVATE(inode));
Better to introduce a local variable for CRYPTFS_INODE_TO_PRIVATE. More readable and smaller kernel text that way.
> + ecryptfs_printk(KERN_DEBUG, "Exit\n"); > +} > + > +/** > + * Set up the ecryptfs inode. > + */ > +static void ecryptfs_read_inode(struct inode *inode) > +{ > + ecryptfs_printk(KERN_DEBUG, "Enter; inode = [%p]\n", inode); > + /* This is where we setup the self-reference in the vfs_inode's > + * u.generic_ip. That way we don't have to walk the list again. */ > + ECRYPTFS_INODE_TO_PRIVATE_SM(inode) = > + list_entry(inode, struct ecryptfs_inode_info, vfs_inode); > + ECRYPTFS_INODE_TO_LOWER(inode) = NULL;
Hmm, ugly, please make the setters explicit instead.
> + inode->i_version++; > + inode->i_op = &ecryptfs_main_iops; > + inode->i_fop = &ecryptfs_main_fops; > + inode->i_mapping->a_ops = &ecryptfs_aops; > + ecryptfs_printk(KERN_DEBUG, "Exit\n"); > +} > + > + > +/** > + * This is called through iput_final(). > + * This is function will replace generic_drop_inode. The end result of which > + * is we are skipping the check in inode->i_nlink, which we do not use. > + */ > +static void ecryptfs_drop_inode(struct inode *inode) {
Formatting
> + generic_delete_inode(inode); > +} > + > +/** > + * Final actions when unmounting a file system. > + * This will handle deallocation and release of our private data. > + */ > +static void ecryptfs_put_super(struct super_block *sb) > +{ > + struct ecryptfs_sb_info *sb_info = ECRYPTFS_SUPERBLOCK_TO_PRIVATE(sb);
You probably want to rename ECRYPTFS_SUPERBLOCK_TO_PRIVATE to ecryptfs_sb or similar.
> + > + ecryptfs_printk(KERN_DEBUG, "Enter\n"); > + mntput(sb_info->lower_mnt); > + key_put(sb_info->mount_crypt_stat.global_auth_tok_key); > + kmem_cache_free(ecryptfs_sb_info_cache, sb_info); > + ECRYPTFS_SUPERBLOCK_TO_PRIVATE_SM(sb) = NULL; > + ecryptfs_printk(KERN_DEBUG, "Exit\n"); > +} > + > +/** > + * Get the filesystem statistics. Currently, we let this pass right through > + * to the lower filesystem and take no action ourselves. > + */ > +static int ecryptfs_statfs(struct super_block *sb, struct kstatfs *buf) > +{ > + int rc = 0;
Redundant initialization
> + > + ecryptfs_printk(KERN_DEBUG, "Enter\n"); > + rc = vfs_statfs(ECRYPTFS_SUPERBLOCK_TO_LOWER(sb), buf); > + ecryptfs_printk(KERN_DEBUG, "Exit; rc = [%d]\n", rc); > + return rc; > +} > + > +/** > + * Called to ask filesystem to change mount options. Not implemented; > + * returns -ENOSYS every time. > + */ > +static int ecryptfs_remount_fs(struct super_block *sb, int *flags, char *data) > +{ > + ecryptfs_printk(KERN_DEBUG, "Enter\n"); > + ecryptfs_printk(KERN_DEBUG, "Exit\n"); > + return -ENOSYS; > +}
Any reason you want to keep this around?
> + > +/** > + * Called by iput() when the inode reference count reached zero > + * and the inode is not hashed anywhere. Used to clear anything > + * that needs to be, before the inode is completely destroyed and put > + * on the inode free list. We use this to drop out reference to the > + * lower inode. > + */ > +static void ecryptfs_clear_inode(struct inode *inode) > +{ > + ecryptfs_printk(KERN_DEBUG, "Enter; inode = [%p]; i_ino = [0x%.16x]\n", > + inode, inode->i_ino); > + iput(ECRYPTFS_INODE_TO_LOWER(inode)); > + ecryptfs_printk(KERN_DEBUG, "Exit\n"); > +} > + > +/** > + * Called in do_umount() if the MNT_FORCE flag was used and this > + * function is defined. See comment in linux/fs/super.c:do_umount(). > + * Used only in nfs, to kill any pending RPC tasks, so that subsequent > + * code can actually succeed and won't leave tasks that need handling. > + */ > +static void ecryptfs_umount_begin(struct vfsmount *vfsmnt, int flags) > +{ > + struct vfsmount *lower_mnt; > + struct super_block *lower_sb; > + > + ecryptfs_printk(KERN_DEBUG, "Enter\n"); > + lower_mnt = ECRYPTFS_SUPERBLOCK_TO_PRIVATE(vfsmnt->mnt_sb)->lower_mnt; > + lower_sb = lower_mnt->mnt_sb; > + if (lower_sb->s_op->umount_begin) > + lower_sb->s_op->umount_begin(lower_mnt, flags); > + ecryptfs_printk(KERN_DEBUG, "Exit\n"); > +} > + > +/** > + * Prints the directory we are currently mounted over > + * > + * @return Zero on success; non-zero otherwise > + */ > +static int ecryptfs_show_options(struct seq_file *m, struct vfsmount *mnt) > +{ > + struct super_block *sb = mnt->mnt_sb; > + int rc = 0; > + char *tmp = NULL; > + char *path; > + > + ecryptfs_printk(KERN_DEBUG, "Enter\n"); > + tmp = (char *)__get_free_page(GFP_KERNEL); > + if (!tmp) { > + rc = -ENOMEM; > + goto out; > + } > + path = d_path(ECRYPTFS_DENTRY_TO_LOWER(sb->s_root), > + ECRYPTFS_SUPERBLOCK_TO_PRIVATE(sb)->lower_mnt, tmp, > + PAGE_SIZE);
Use of local variables probably would clean that up
> + seq_printf(m, ",dir=%s", path); > + free_page((unsigned long)tmp); > +out: > + ecryptfs_printk(KERN_DEBUG, "Exit; rc = [%d]\n", rc); > + return rc; > +} > + > +struct super_operations ecryptfs_sops = { > + .alloc_inode = ecryptfs_alloc_inode, > + .destroy_inode = ecryptfs_destroy_inode, > + .read_inode = ecryptfs_read_inode, > + .drop_inode = ecryptfs_drop_inode, > + .put_super = ecryptfs_put_super, > + .statfs = ecryptfs_statfs, > + .remount_fs = ecryptfs_remount_fs, > + .clear_inode = ecryptfs_clear_inode, > + .umount_begin = ecryptfs_umount_begin, > + .show_options = ecryptfs_show_options > +}; > - > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.tux.org/lkml/ > - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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