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exofs: Move all operations to an io_engine

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In anticipation for multi-device operations, we separate osd operations
into an abstract I/O API. Currently only one device is used but later
when adding more devices, we will drive all devices in parallel according
to a "data_map" that describes how data is arranged on multiple devices.
The file system level operates, like before, as if there is one object
(inode-number) and an i_size. The io engine will split this to the same
object-number but on multiple device.

At first we introduce Mirror (raid 1) layout. But at the final outcome
we intend to fully implement the pNFS-Objects data-map, including
raid 0,4,5,6 over mirrored devices, over multiple device-groups. And
more. See: http://tools.ietf.org/html/draft-ietf-nfsv4-pnfs-obj-12

* Define an io_state based API for accessing osd storage devices
  in an abstract way.
  Usage:
	First a caller allocates an io state with:
		exofs_get_io_state(struct exofs_sb_info *sbi,
				   struct exofs_io_state** ios);

	Then calles one of:
		exofs_sbi_create(struct exofs_io_state *ios);
		exofs_sbi_remove(struct exofs_io_state *ios);
		exofs_sbi_write(struct exofs_io_state *ios);
		exofs_sbi_read(struct exofs_io_state *ios);
		exofs_oi_truncate(struct exofs_i_info *oi, u64 new_len);

	And when done
		exofs_put_io_state(struct exofs_io_state *ios);

* Convert all source files to use this new API
* Convert from bio_alloc to bio_kmalloc
* In io engine we make use of the now fixed osd_req_decode_sense

There are no functional changes or on disk additions after this patch.

Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
This commit is contained in:
Boaz Harrosh
2009-11-08 14:54:08 +02:00
parent 8ce9bdd1fb
commit 06886a5a3d
5 changed files with 646 additions and 352 deletions
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87
fs/exofs/exofs.h
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@@ -30,14 +30,13 @@
* along with exofs; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*/
#ifndef __EXOFS_H__
#define __EXOFS_H__
#include <linux/fs.h>
#include <linux/time.h>
#include "common.h"
#ifndef __EXOFS_H__
#define __EXOFS_H__
#define EXOFS_ERR(fmt, a...) printk(KERN_ERR "exofs: " fmt, ##a)
#ifdef CONFIG_EXOFS_DEBUG
@@ -56,6 +55,7 @@
*/
struct exofs_sb_info {
struct osd_dev *s_dev; /* returned by get_osd_dev */
struct exofs_fscb s_fscb; /* Written often, pre-allocate*/
osd_id s_pid; /* partition ID of file system*/
int s_timeout; /* timeout for OSD operations */
uint64_t s_nextid; /* highest object ID used */
@@ -79,6 +79,50 @@ struct exofs_i_info {
struct inode vfs_inode; /* normal in-memory inode */
};
static inline osd_id exofs_oi_objno(struct exofs_i_info *oi)
{
return oi->vfs_inode.i_ino + EXOFS_OBJ_OFF;
}
struct exofs_io_state;
typedef void (*exofs_io_done_fn)(struct exofs_io_state *or, void *private);
struct exofs_io_state {
struct kref kref;
void *private;
exofs_io_done_fn done;
struct exofs_sb_info *sbi;
struct osd_obj_id obj;
u8 *cred;
/* Global read/write IO*/
loff_t offset;
unsigned long length;
void *kern_buff;
struct bio *bio;
/* Attributes */
unsigned in_attr_len;
struct osd_attr *in_attr;
unsigned out_attr_len;
struct osd_attr *out_attr;
/* Variable array of size numdevs */
unsigned numdevs;
struct exofs_per_dev_state {
struct osd_request *or;
struct bio *bio;
} per_dev[];
};
static inline unsigned exofs_io_state_size(unsigned numdevs)
{
return sizeof(struct exofs_io_state) +
sizeof(struct exofs_per_dev_state) * numdevs;
}
/*
* our inode flags
*/
@@ -130,6 +174,42 @@ static inline struct exofs_i_info *exofs_i(struct inode *inode)
/*************************
* function declarations *
*************************/
/* ios.c */
void exofs_make_credential(u8 cred_a[OSD_CAP_LEN],
const struct osd_obj_id *obj);
int exofs_read_kern(struct osd_dev *od, u8 *cred, struct osd_obj_id *obj,
u64 offset, void *p, unsigned length);
int exofs_get_io_state(struct exofs_sb_info *sbi, struct exofs_io_state** ios);
void exofs_put_io_state(struct exofs_io_state *ios);
int exofs_check_io(struct exofs_io_state *ios, u64 *resid);
int exofs_sbi_create(struct exofs_io_state *ios);
int exofs_sbi_remove(struct exofs_io_state *ios);
int exofs_sbi_write(struct exofs_io_state *ios);
int exofs_sbi_read(struct exofs_io_state *ios);
int extract_attr_from_ios(struct exofs_io_state *ios, struct osd_attr *attr);
int exofs_oi_truncate(struct exofs_i_info *oi, u64 new_len);
static inline int exofs_oi_write(struct exofs_i_info *oi,
struct exofs_io_state *ios)
{
ios->obj.id = exofs_oi_objno(oi);
ios->cred = oi->i_cred;
return exofs_sbi_write(ios);
}
static inline int exofs_oi_read(struct exofs_i_info *oi,
struct exofs_io_state *ios)
{
ios->obj.id = exofs_oi_objno(oi);
ios->cred = oi->i_cred;
return exofs_sbi_read(ios);
}
/* inode.c */
void exofs_truncate(struct inode *inode);
int exofs_setattr(struct dentry *, struct iattr *);
@@ -169,6 +249,7 @@ extern const struct file_operations exofs_file_operations;
/* inode.c */
extern const struct address_space_operations exofs_aops;
extern const struct osd_attr g_attr_logical_length;
/* namei.c */
extern const struct inode_operations exofs_dir_inode_operations;