Greetings,
Here is part 2 of the EVMS core. This is the common header file included by
the core and all the plugins, and defines commonly used structures and macros.
Kevin Corry
[email protected]
http://evms.sourceforge.net/
diff -Naur linux-2.5.40/include/linux/evms/evms.h linux-2.5.40-evms/include/linux/evms/evms.h
--- linux-2.5.40/include/linux/evms/evms.h Sun Jul 17 18:46:18 1994
+++ linux-2.5.40-evms/include/linux/evms/evms.h Tue Oct 1 15:30:14 2002
@@ -0,0 +1,613 @@
+/* -*- linux-c -*- */
+/*
+ * Copyright (c) International Business Machines Corp., 2000
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See
+ * the GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ */
+/*
+ * linux/include/linux/evms/evms.h
+ *
+ * EVMS kernel header file
+ *
+ */
+
+#ifndef __EVMS_INCLUDED__
+#define __EVMS_INCLUDED__
+
+#include <linux/blk.h>
+#include <linux/genhd.h>
+#include <linux/fs.h>
+#include <linux/iobuf.h>
+#include <linux/kdev_t.h>
+#include <linux/hdreg.h>
+#include <linux/slab.h>
+#include <linux/proc_fs.h>
+#include <linux/major.h>
+#include <linux/mempool.h>
+
+/**
+ * version info
+ **/
+#define EVMS_MAJOR_VERSION 1
+#define EVMS_MINOR_VERSION 2
+#define EVMS_PATCHLEVEL_VERSION 0
+
+/**
+ * general defines section
+ **/
+#define FALSE 0
+#define TRUE 1
+
+#define MAX_EVMS_VOLUMES 256
+#define EVMS_VOLUME_NAME_SIZE 127
+#define IBM_OEM_ID 8112
+#define EVMS_INITIAL_CRC 0xFFFFFFFF
+#define EVMS_MAGIC_CRC 0x31415926
+#define EVMS_VSECTOR_SIZE 512
+#define EVMS_VSECTOR_SIZE_SHIFT 9
+
+#define DEV_PATH "/dev"
+#define EVMS_DIR_NAME "evms"
+#define EVMS_DEV_NAME "block_device"
+#define EVMS_DEV_NODE_PATH DEV_PATH "/" EVMS_DIR_NAME "/"
+#define EVMS_DEVICE_NAME DEV_PATH "/" EVMS_DIR_NAME "/" EVMS_DEV_NAME
+
+/**
+ * list_for_each_entry_safe - iterate over list safe against removal of list entry
+ * @pos: the type * to use as a loop counter.
+ * @n: another type * to use as temporary storage
+ * @head: the head for your list.
+ * @member: the name of the list_struct within the struct.
+ */
+#define list_for_each_entry_safe(pos, n, head, member) \
+ for (pos = list_entry((head)->next, typeof(*pos), member), \
+ n = list_entry(pos->member.next, typeof(*pos), member); \
+ &pos->member != (head); \
+ pos = n, \
+ n = list_entry(pos->member.next, typeof(*pos), member))
+/**
+ * list_member - tests whether a list member is currently on a list
+ * @member: member to evaulate
+ */
+static inline int
+list_member(struct list_head *member)
+{
+ return ((!member->next || !member->prev) ? FALSE : TRUE);
+}
+
+/**
+ * kernel logging levels defines
+ **/
+#define EVMS_INFO_CRITICAL 0
+#define EVMS_INFO_SERIOUS 1
+#define EVMS_INFO_ERROR 2
+#define EVMS_INFO_WARNING 3
+#define EVMS_INFO_DEFAULT 5
+#define EVMS_INFO_DETAILS 6
+#define EVMS_INFO_DEBUG 7
+#define EVMS_INFO_EXTRA 8
+#define EVMS_INFO_ENTRY_EXIT 9
+#define EVMS_INFO_EVERYTHING 10
+
+/**
+ * kernel logging level variable
+ **/
+extern int evms_info_level;
+
+/**
+ * kernel logging macros
+ **/
+#define evmsLOG(info_level,prspec) { if (evms_info_level >= info_level) printk prspec; }
+#define evmsLOG2(info_level,statement) { if (evms_info_level >= info_level) statement; }
+
+/**
+ * LOG MACROS to make evms log messages
+ * look much cleaner in the source.
+ **/
+#define EVMS_LOG_PREFIX "evms: "
+#define LOG_CRITICAL(msg, args...) evmsLOG(EVMS_INFO_CRITICAL, (KERN_CRIT EVMS_LOG_PREFIX LOG_PREFIX msg, ## args))
+#define LOG_SERIOUS(msg, args...) evmsLOG(EVMS_INFO_SERIOUS, (KERN_ERR EVMS_LOG_PREFIX LOG_PREFIX msg, ## args))
+#define LOG_ERROR(msg, args...) evmsLOG(EVMS_INFO_ERROR, (KERN_ERR EVMS_LOG_PREFIX LOG_PREFIX msg, ## args))
+#define LOG_WARNING(msg, args...) evmsLOG(EVMS_INFO_WARNING, (KERN_WARNING EVMS_LOG_PREFIX LOG_PREFIX msg, ## args))
+#define LOG_DEFAULT(msg, args...) evmsLOG(EVMS_INFO_DEFAULT, (KERN_INFO EVMS_LOG_PREFIX LOG_PREFIX msg, ## args))
+#define LOG_DETAILS(msg, args...) evmsLOG(EVMS_INFO_DETAILS, (KERN_INFO EVMS_LOG_PREFIX LOG_PREFIX msg, ## args))
+#define LOG_DEBUG(msg, args...) evmsLOG(EVMS_INFO_DEBUG, (KERN_INFO EVMS_LOG_PREFIX LOG_PREFIX msg, ## args))
+#define LOG_EXTRA(msg, args...) evmsLOG(EVMS_INFO_EXTRA, (KERN_INFO EVMS_LOG_PREFIX LOG_PREFIX msg, ## args))
+#define LOG_ENTRY_EXIT(msg, args...) evmsLOG(EVMS_INFO_ENTRY_EXIT, (KERN_INFO EVMS_LOG_PREFIX LOG_PREFIX msg, ## args))
+#define LOG_EVERYTHING(msg, args...) evmsLOG(EVMS_INFO_EVERYTHING, (KERN_INFO EVMS_LOG_PREFIX LOG_PREFIX msg, ## args))
+
+/**
+ * Macros to cleanly print 64-bit numbers on both 32-bit and 64-bit machines.
+ * Use these in place of %Ld, %Lu, and %Lx.
+ **/
+#if BITS_PER_LONG > 32
+#define PFD64 "%ld"
+#define PFU64 "%lu"
+#define PFX64 "%lx"
+#else
+#define PFD64 "%Ld"
+#define PFU64 "%Lu"
+#define PFX64 "%Lx"
+#endif
+
+/**
+ * helpful PROCFS macro
+ **/
+#ifdef CONFIG_PROC_FS
+#define PROCPRINT(msg, args...) (sz += sprintf(page + sz, msg, ## args));\
+ if (sz < off)\
+ off -= sz, sz = 0;\
+ else if (sz >= off + count)\
+ goto out
+#endif
+
+/**
+ * PluginID convenience macros
+ *
+ * An EVMS PluginID is a 32-bit number with the following bit positions:
+ * Top 16 bits: OEM identifier. See IBM_OEM_ID.
+ * Next 4 bits: Plugin type identifier. See evms_plugin_code.
+ * Lowest 12 bits: Individual plugin identifier within a given plugin type.
+ **/
+#define SetPluginID(oem, type, id) ((oem << 16) | (type << 12) | id)
+#define GetPluginOEM(pluginid) (pluginid >> 16)
+#define GetPluginType(pluginid) ((pluginid >> 12) & 0xf)
+#define GetPluginID(pluginid) (pluginid & 0xfff)
+
+/**
+ * enum evms_plugin_type - evms plugin types
+ **/
+enum evms_plugin_code {
+ EVMS_NO_PLUGIN = 0,
+ EVMS_DEVICE_MANAGER,
+ EVMS_SEGMENT_MANAGER,
+ EVMS_REGION_MANAGER,
+ EVMS_FEATURE,
+ EVMS_ASSOCIATIVE_FEATURE,
+ EVMS_FILESYSTEM_INTERFACE_MODULE,
+ EVMS_CLUSTER_MANAGER_INTERFACE_MODULE,
+ EVMS_DISTRIBUTED_LOCK_MANAGER_INTERFACE_MODULE
+};
+
+/**
+ * struct evms_version -
+ * @major: changes when incompatible difference are introduced
+ * @minor: changes when additions are made
+ * @patchlevel: reflects bug level fixes within a particular major/minor pair
+ *
+ * generic versioning info used by EVMS
+ **/
+struct evms_version {
+ u32 major;
+ u32 minor;
+ u32 patchlevel;
+};
+
+/**
+ * struct evms_plugin_header - kernel plugin header record
+ * @id: plugin id
+ * @version: plugin version
+ * @required_services_version: required common services version
+ * @fops: table of function operations
+ * @headers: list member field
+ *
+ * kernel plugin header record
+ **/
+struct evms_plugin_header {
+ u32 id;
+ struct evms_version version;
+ struct evms_version required_services_version;
+ struct evms_plugin_fops *fops;
+ struct list_head headers;
+};
+
+/**
+ * struct evms_feature_header - EVMS generic on-disk header for features
+ * @signature: unique magic number
+ * @crc: structure's crc
+ * @version: feature header version
+ * @engine_version: created by this evms engine version
+ * @flags: feature characteristics, bit definitions below.
+ * @feature_id: indicates which feature this header is describing
+ * @sequence_number: describes most recent copy of redundant metadata
+ * @alignment_padding: used when objects are moved between different sized devices
+ * @feature_data1_start_lsn: object relative start of 1st copy feature data
+ * @feature_data1_size: size of 1st copy of feature data
+ * @feature_data2_start_lsn: object relative start of 2nd copy feature data
+ * @feature_data2_size: size of 2nd copy of feature data
+ * @volume_serial_number: unique/persistent volume identifier
+ * @volume_system_id: unique/persistent minor number
+ * @object_depth: depth of object in volume tree
+ * @object_name: object's name
+ * @volume_name: volume name object is a part of
+ * @pad: padding to make structure be 512 byte aligned
+ *
+ * generic on-disk header used to describe any EVMS feature
+ * NOTE: 2nd copy of feature data is optional, if used set start_lsn to 0.
+ **/
+struct evms_feature_header {
+ u32 signature;
+ u32 crc;
+ struct evms_version version;
+ struct evms_version engine_version;
+ u32 flags;
+ u32 feature_id;
+ u64 sequence_number;
+ u64 alignment_padding;
+ u64 feature_data1_start_lsn;
+ u64 feature_data1_size;
+ u64 feature_data2_start_lsn;
+ u64 feature_data2_size;
+ u64 volume_serial_number;
+ u32 volume_system_id;
+ u32 object_depth;
+ u8 object_name[EVMS_VOLUME_NAME_SIZE + 1];
+ u8 volume_name[EVMS_VOLUME_NAME_SIZE + 1];
+ u8 pad[152];
+};
+
+/**
+ * field evms_feature_header.signature majic number
+ **/
+#define EVMS_FEATURE_HEADER_SIGNATURE 0x54414546 /* FEAT */
+/**
+ * field evms_feature_header.flags defines
+ **/
+#define EVMS_FEATURE_ACTIVE (1<<0)
+#define EVMS_FEATURE_VOLUME_COMPLETE (1<<1)
+#define EVMS_VOLUME_DATA_OBJECT (1<<16)
+#define EVMS_VOLUME_DATA_STOP (1<<17)
+/**
+ * struct evms_feature_header version info
+ **/
+#define EVMS_FEATURE_HEADER_MAJOR 3
+#define EVMS_FEATURE_HEADER_MINOR 0
+#define EVMS_FEATURE_HEADER_PATCHLEVEL 0
+
+/**
+ * EVMS specific error codes
+ **/
+#define EVMS_FEATURE_FATAL_ERROR 257
+#define EVMS_VOLUME_FATAL_ERROR 258
+#define EVMS_FEATURE_INCOMPLETE_ERROR 259
+
+/**
+ * struct evms_volume_info - exported volume info
+ * @volume_sn: unique volume identifier
+ * @volume_minor: persistent device minor assigned to this volume
+ * @volume_name: persistent name assigned to this volume
+ *
+ * a collection of volume specific info
+ **/
+struct evms_volume_info {
+ u64 volume_sn;
+ u32 volume_minor;
+ u8 volume_name[EVMS_VOLUME_NAME_SIZE + 1];
+};
+
+/**
+ * struct evms_logical_node - generic kernel storage object
+ * @total_vsectors: 0 size of this object in 512 byte units
+ * @plugin: 8 plugin that created/owns/manages this storage object
+ * @private: 12 location for owner to store private info
+ * @flags: 16 storage object characteristics (set/used by plugins)
+ * bit definitions located in evms_common.h
+ * @iflags: 20 internal flags (used exclusively by the framework, not for plugins to use/set)
+ * bit definitions below.
+ * @hardsector_size: 24 assumed physical sector size of underlying device
+ * @block_size: 28 default block size for this object
+ * @system_id: 32 system indicator (set by the segment manager)
+ * @volume_info: 36 persistent volume info, used only by EVMS volumes
+ * @feature_header: 40 generic on-disk metadata describing any EVMS feature
+ * @next: 44 linked list field
+ * @discover: 48 discover list field
+ * @device: 56 device list field
+ * @fbottom: 64 bottom-most feature object list field
+ * @removable: 72 changed removable media list field
+ * @consumer: 80 list field for use by the object's consumer
+ * @name: 88 storage object name
+ * 216
+ *
+ * generic kernel storage object
+ */
+struct evms_logical_node {
+ u64 total_vsectors;
+ struct evms_plugin_header *plugin;
+ void *private;
+ u32 flags;
+ u32 iflags;
+ int hardsector_size;
+ int block_size;
+ u32 system_id;
+ struct evms_volume_info *volume_info;
+ struct evms_feature_header *feature_header;
+ void *consumer_private;
+ struct list_head consumed;
+ struct list_head produced;
+ struct list_head discover;
+ struct list_head device;
+ struct list_head fbottom;
+ struct list_head removable;
+ u8 name[EVMS_VOLUME_NAME_SIZE + 1];
+};
+
+/**
+ * fields evms_logical_node.flags & evms_logical_volume.flags defines
+ **/
+#define EVMS_FLAGS_WIDTH 32
+#define EVMS_VOLUME_FLAG (1<<0)
+#define EVMS_VOLUME_PARTIAL_FLAG (1<<1)
+#define EVMS_VOLUME_PARTIAL (1<<1)
+#define EVMS_VOLUME_SET_READ_ONLY (1<<2)
+#define EVMS_VOLUME_READ_ONLY (1<<2)
+/**
+ * these bits define volume status
+ **/
+#define EVMS_MEDIA_CHANGED (1<<20)
+#define EVMS_DEVICE_UNPLUGGED (1<<21)
+/**
+ * these bits used for removable status
+ **/
+#define EVMS_DEVICE_MEDIA_PRESENT (1<<24)
+#define EVMS_DEVICE_PRESENT (1<<25)
+#define EVMS_DEVICE_LOCKABLE (1<<26)
+#define EVMS_DEVICE_REMOVABLE (1<<27)
+
+/**
+ * fields evms_logical_node.iflags defines
+ **/
+#define EVMS_FEATURE_BOTTOM (1<<0)
+#define EVMS_TOP_SEGMENT (1<<1)
+
+/**
+ * macro to obtain a node's name from either EVMS or compatibility volumes
+ **/
+#define EVMS_GET_NODE_NAME(node) \
+ ((node->flags & EVMS_VOLUME_FLAG) ? \
+ node->volume_info->volume_name : \
+ node->name)
+
+/**
+ * macro used to transform to/from userland device handles and device storage object nodes
+ **/
+#define EVMS_HANDLE_KEY 0x0123456789ABCDEF
+#define DEV_HANDLE_TO_NODE(handle) ((struct evms_logical_node *)(unsigned long)((handle) ^ EVMS_HANDLE_KEY))
+#define NODE_TO_DEV_HANDLE(node) (((u64)(unsigned long)(node)) ^ EVMS_HANDLE_KEY)
+
+/**
+ * struct evms_logical_volume - logical volume info
+ * @name: logical volume name
+ * @node: logical volume storage object
+ * @minor: device minor assigned to volume
+ * @flags: characteristics of logical volume
+ * @quiesced: quiesce state info
+ * @vfs_quiesced: vfs quiesce state info
+ * @requests_in_progress: count of in-flight I/Os
+ * @wait_queue: used when volume is quiesced
+ * @gd: gendisk entry for the volume
+ * @request_queue: unique request queue
+ * @request_lock: unique request queue lock
+ * @volumes: list member field
+ *
+ * contains all the fields needed to manage to a logical volume
+ **/
+struct evms_logical_volume {
+ u8 *name;
+ struct evms_logical_node *node;
+ int minor;
+ int flags;
+ int quiesced;
+ int vfs_quiesced;
+ atomic_t requests_in_progress;
+ wait_queue_head_t wait_queue;
+ struct gendisk *gd;
+ request_queue_t request_queue;
+ spinlock_t request_lock;
+ struct list_head volumes;
+};
+
+/**
+ * field evms_logical_volume.flags defines
+ **/
+/**
+ * queued flags bits
+ **/
+#define EVMS_REQUESTED_DELETE (1<<5)
+#define EVMS_REQUESTED_QUIESCE (1<<6)
+#define EVMS_REQUESTED_VFS_QUIESCE (1<<7)
+/**
+ * this bit indicates corruption
+ **/
+#define EVMS_VOLUME_CORRUPT (1<<8)
+/**
+ * these bits define the source of the corruption
+ **/
+#define EVMS_VOLUME_SOFT_DELETED (1<<9)
+#define EVMS_DEVICE_UNAVAILABLE (1<<10)
+
+/*
+ * The following function table is used for all plugins.
+ */
+/**
+ * struct evms_plugin_fops - evms plugin's table of function operations
+ * @discover: volume discovery entry point
+ * @end_discover: final discovery entry point
+ * @delete: delete volume entry point
+ * @submit_io: asynchronous read/write entry point
+ * @init_io: synchronous io entry point
+ * @ioctl: generic ioctl entry point
+ * @direct_ioctl: non-generic ioctl entry point
+ *
+ * evms plugin's table of function operations
+ **/
+struct evms_plugin_fops {
+ int (*discover) (struct list_head *);
+ int (*end_discover) (struct list_head *);
+ int (*delete) (struct evms_logical_node *);
+ void (*submit_io) (struct evms_logical_node *, struct bio *);
+ int (*init_io) (struct evms_logical_node *, int, u64,
+ u64, void *);
+ int (*ioctl) (struct evms_logical_node *, struct inode *,
+ struct file *, u32, unsigned long);
+ int (*direct_ioctl) (struct inode *, struct file *,
+ u32, unsigned long);
+};
+
+/**
+ * convenience macros to use plugin's fops entry points
+ **/
+#define DISCOVER(node, list) ((plugin)->fops->discover(list))
+#define END_DISCOVER(node, list) ((plugin)->fops->end_discover(list))
+#define DELETE(node) ((node)->plugin->fops->delete(node))
+#define SUBMIT_IO(node, bio) ((node)->plugin->fops->submit_io(node, bio))
+#define INIT_IO(node, rw_flag, start_sec, num_secs, buf_addr) ((node)->plugin->fops->init_io(node, rw_flag, start_sec, num_secs, buf_addr))
+#define IOCTL(node, inode, file, cmd, arg) ((node)->plugin->fops->ioctl(node, inode, file, cmd, arg))
+#define DIRECT_IOCTL(plugin, inode, file, cmd, arg) ((plugin)->fops->direct_ioctl(inode, file, cmd, arg))
+
+/**
+ * struct evms_list_node - generic non-imbedded list node object
+ * @item: ptr to object in list
+ * @next: ptr to next item in list
+ *
+ * light weight generic non-imbedded list object definition
+ **/
+struct evms_list_node {
+ void *item;
+ struct evms_list_node *next;
+};
+
+/**
+ * struct evms_pool_mgmt - anchor block for private pool management
+ * @cachep: kmem_cache_t variable
+ * @member_size: size of each element in the pool
+ * @head:
+ * @waiters: count of waiters
+ * @wait_queue: list of waiters
+ * @name: name of the pool (must be less than 20 chars)
+ *
+ * anchor block for private pool management
+ **/
+struct evms_pool_mgmt {
+ kmem_cache_t *cachep;
+ int member_size;
+ void *head;
+ atomic_t waiters;
+ wait_queue_head_t wait_queue;
+ u8 *name;
+};
+
+/*
+ * Notes:
+ * All of the following kernel thread functions belong to EVMS base.
+ * These functions were copied from md_core.c
+ */
+#define EVMS_THREAD_WAKEUP 0
+/**
+ * struct evms_thread
+ * @run:
+ * @data:
+ * @wqueue: thread wait queue
+ * @flags: thread attributes
+ * @event: event completion
+ * @tsk: task info
+ * @name: thread name
+ *
+ * data structure for creating/managing a kernel thread
+ **/
+struct evms_thread {
+ void (*run) (void *data);
+ void *data;
+ wait_queue_head_t wqueue;
+ unsigned long flags;
+ struct completion *event;
+ struct task_struct *tsk;
+ const u8 *name;
+};
+
+/**
+ * struct bio_split_cb - bio split control block structure definition
+ * @rc:
+ * @sector:
+ * @original_bio:
+ * @outstanding_bios:
+ * @pool:
+ *
+ * control block for managing bio splitting
+ **/
+struct bio_split_cb {
+ int rc;
+ u64 sector;
+ struct bio *original_bio;
+ atomic_t outstanding_bios;
+ mempool_t *bio_pool;
+ mempool_t *split_pool;
+};
+
+/**
+ * EVMS (common services) exported functions prototypes
+ *
+ * since these function names are global, evms_cs_ has been prepended
+ * to each function name, to ensure they do not collide with any
+ * other global functions in the kernel.
+ **/
+#define EVMS_COMMON_SERVICES_MAJOR 0
+#define EVMS_COMMON_SERVICES_MINOR 6
+#define EVMS_COMMON_SERVICES_PATCHLEVEL 0
+
+void evms_cs_get_version(int *, int *);
+int evms_cs_check_version(struct evms_version *, struct evms_version *);
+int evms_cs_register_plugin(struct evms_plugin_header *);
+int evms_cs_unregister_plugin(struct evms_plugin_header *);
+#ifdef EVMS_MEM_DEBUG
+int evms_cs_verify_memory_integrity(int);
+#endif
+int evms_cs_allocate_logical_node(struct evms_logical_node **);
+void evms_cs_deallocate_volume_info(struct evms_logical_node *);
+void evms_cs_deallocate_logical_node(struct evms_logical_node *);
+int evms_cs_kernel_ioctl(struct evms_logical_node *, u32,
+ unsigned long);
+inline unsigned long evms_cs_size_in_vsectors(long long);
+inline int evms_cs_log2(long long);
+u32 evms_cs_calculate_crc(u32, void *, u32);
+int evms_cs_register_for_end_io_notification(void *,
+ struct bio *,
+ void *callback_function);
+struct evms_list_node **evms_cs_lookup_item_in_list(struct evms_list_node **,
+ void *);
+void evms_cs_signal_event(int);
+struct evms_thread *evms_cs_register_thread(void (*run) (void *),
+ void *data, const u8 *name);
+void evms_cs_unregister_thread(struct evms_thread *thread);
+void evms_cs_wakeup_thread(struct evms_thread *thread);
+void evms_cs_interrupt_thread(struct evms_thread *thread);
+struct proc_dir_entry *evms_cs_get_evms_proc_dir(void);
+int evms_cs_volume_request_in_progress(kdev_t, int, int *);
+void evms_cs_invalidate_volume(struct evms_logical_node *topmost_node);
+int evms_cs_split_bio(struct bio *, u64, struct bio **, struct bio **,
+ mempool_t *, mempool_t *);
+request_queue_t *evms_find_queue(kdev_t dev);
+
+/* EVMS exported global variables */
+extern struct evms_pool_mgmt *evms_bio_pool;
+extern u8 *evms_primary_string;
+extern u8 *evms_secondary_string;
+extern struct list_head evms_device_list;
+
+/* Have to include this at the end, since it depends
+ * on structures and definitions in this file.
+ */
+#include <linux/evms/evms_ioctl.h>
+
+#endif
> diff -Naur linux-2.5.40/include/linux/evms/evms.h linux-2.5.40-evms/include/linux/evms/evms.h
> --- linux-2.5.40/include/linux/evms/evms.h Sun Jul 17 18:46:18 1994
> +++ linux-2.5.40-evms/include/linux/evms/evms.h Tue Oct 1 15:30:14 2002
What about drivers/md?
> @@ -0,0 +1,613 @@
> +/* -*- linux-c -*- */
> +/*
> + * Copyright (c) International Business Machines Corp., 2000
Has this file _really_ not been touched for two years??
> +/*
> + * linux/include/linux/evms/evms.h
> + *
> + * EVMS kernel header file
> + *
> + */
This comment sais exactly nothing. You aswell just remove it..
> +
> +#ifndef __EVMS_INCLUDED__
> +#define __EVMS_INCLUDED__
> +
> +#include <linux/blk.h>
> +#include <linux/genhd.h>
> +#include <linux/fs.h>
> +#include <linux/iobuf.h>
I can't see the need for this include anywhere in the file. Please check
whether you need all these includes.
> +
> +/**
> + * general defines section
> + **/
> +#define FALSE 0
> +#define TRUE 1
Please just use 0/1 directly just like everyone else..
> +#define DEV_PATH "/dev"
> +#define EVMS_DIR_NAME "evms"
> +#define EVMS_DEV_NAME "block_device"
> +#define EVMS_DEV_NODE_PATH DEV_PATH "/" EVMS_DIR_NAME "/"
> +#define EVMS_DEVICE_NAME DEV_PATH "/" EVMS_DIR_NAME "/" EVMS_DEV_NAME
The kernel doesn't know about device names at all.
> +
> +/**
> + * list_for_each_entry_safe - iterate over list safe against removal of list entry
> + * @pos: the type * to use as a loop counter.
> + * @n: another type * to use as temporary storage
> + * @head: the head for your list.
> + * @member: the name of the list_struct within the struct.
> + */
> +#define list_for_each_entry_safe(pos, n, head, member) \
> + for (pos = list_entry((head)->next, typeof(*pos), member), \
> + n = list_entry(pos->member.next, typeof(*pos), member); \
> + &pos->member != (head); \
> + pos = n, \
> + n = list_entry(pos->member.next, typeof(*pos), member))
> +/**
> + * list_member - tests whether a list member is currently on a list
> + * @member: member to evaulate
> + */
> +static inline int
> +list_member(struct list_head *member)
> +{
> + return ((!member->next || !member->prev) ? FALSE : TRUE);
> +}
This should go into list.h
> +
> +/**
> + * kernel logging levels defines
> + **/
> +#define EVMS_INFO_CRITICAL 0
> +#define EVMS_INFO_SERIOUS 1
> +#define EVMS_INFO_ERROR 2
> +#define EVMS_INFO_WARNING 3
> +#define EVMS_INFO_DEFAULT 5
> +#define EVMS_INFO_DETAILS 6
> +#define EVMS_INFO_DEBUG 7
> +#define EVMS_INFO_EXTRA 8
> +#define EVMS_INFO_ENTRY_EXIT 9
> +#define EVMS_INFO_EVERYTHING 10
What about just using normal logging levels?
> +/**
> + * helpful PROCFS macro
> + **/
> +#ifdef CONFIG_PROC_FS
> +#define PROCPRINT(msg, args...) (sz += sprintf(page + sz, msg, ## args));\
> + if (sz < off)\
> + off -= sz, sz = 0;\
> + else if (sz >= off + count)\
> + goto out
> +#endif
I think this really wants to be converted to the seq_file interface..
> +
> +/**
> + * PluginID convenience macros
> + *
> + * An EVMS PluginID is a 32-bit number with the following bit positions:
> + * Top 16 bits: OEM identifier. See IBM_OEM_ID.
> + * Next 4 bits: Plugin type identifier. See evms_plugin_code.
> + * Lowest 12 bits: Individual plugin identifier within a given plugin type.
> + **/
> +#define SetPluginID(oem, type, id) ((oem << 16) | (type << 12) | id)
> +#define GetPluginOEM(pluginid) (pluginid >> 16)
> +#define GetPluginType(pluginid) ((pluginid >> 12) & 0xf)
> +#define GetPluginID(pluginid) (pluginid & 0xfff)
What is the prupose of OEM IDs?
> +struct evms_plugin_header {
> + u32 id;
> + struct evms_version version;
> + struct evms_version required_services_version;
> + struct evms_plugin_fops *fops;
> + struct list_head headers;
> +};
What is the required services version?
> +struct evms_plugin_fops {
What about evms_plugin_ops?
> + int (*ioctl) (struct evms_logical_node *, struct inode *,
> + struct file *, u32, unsigned long);
> + int (*direct_ioctl) (struct inode *, struct file *,
> + u32, unsigned long);
Umm, why do you need two ioctl handlers?
> +/**
> + * convenience macros to use plugin's fops entry points
> + **/
> +#define DISCOVER(node, list) ((plugin)->fops->discover(list))
> +#define END_DISCOVER(node, list) ((plugin)->fops->end_discover(list))
> +#define DELETE(node) ((node)->plugin->fops->delete(node))
> +#define SUBMIT_IO(node, bio) ((node)->plugin->fops->submit_io(node, bio))
> +#define INIT_IO(node, rw_flag, start_sec, num_secs, buf_addr) ((node)->plugin->fops->init_io(node, rw_flag, start_sec, num_secs, buf_addr))
> +#define IOCTL(node, inode, file, cmd, arg) ((node)->plugin->fops->ioctl(node, inode, file, cmd, arg))
> +#define DIRECT_IOCTL(plugin, inode, file, cmd, arg) ((plugin)->fops->direct_ioctl(inode, file, cmd, arg))
Do you really need those wrapper? They just obsfucate the code
> +/**
> + * struct evms_pool_mgmt - anchor block for private pool management
> + * @cachep: kmem_cache_t variable
> + * @member_size: size of each element in the pool
> + * @head:
> + * @waiters: count of waiters
> + * @wait_queue: list of waiters
> + * @name: name of the pool (must be less than 20 chars)
> + *
> + * anchor block for private pool management
> + **/
> +struct evms_pool_mgmt {
> + kmem_cache_t *cachep;
> + int member_size;
> + void *head;
> + atomic_t waiters;
> + wait_queue_head_t wait_queue;
> + u8 *name;
> +};
What's the pruipose of this? Is it really evms-specific?
> +
> +/*
> + * Notes:
> + * All of the following kernel thread functions belong to EVMS base.
> + * These functions were copied from md_core.c
> + */
What about moving them to the core kernel code so everyone
can use them?
> +/* Have to include this at the end, since it depends
> + * on structures and definitions in this file.
> + */
> +#include <linux/evms/evms_ioctl.h>
Just remove this and make the individual sources include it
On 10/04/2002 at 9:03 AM, Kevin Corry wrote:
> > <snip...>
> >
> > > Possibly shortened to:
> > >
> > > static inline int list_member(struct list_head *member)
> > > {
> > > return member->next && member->prev;
> > > }
> > >
> > > Faster, and (at least to me) it looks more obvious.
> >
> > Yes, this may be shorter. However with this change
> > the return type would also need to be changed to
> > portable across archs.
> What would the return type have to be?
Ok, I was (incorrectly) thinking this would return
a *list_head, but after waking up a bit more I see
the "&&" which should return a int.
So I agree Robert's improvement is fine!
Mark