alistair23-linux/fs/exofs/exofs.h
Boaz Harrosh 9e9db45649 exofs: ios: Move to a per inode components & device-table
Exofs raid engine was saving on memory space by having a single layout-info,
single pid, and a single device-table, global to the filesystem. Then passing
a credential and object_id info at the io_state level, private for each
inode. It would also devise this contraption of rotating the device table
view for each inode->ino to spread out the device usage.

This is not compatible with the pnfs-objects standard, demanding that
each inode can have it's own layout-info, device-table, and each object
component it's own pid, oid and creds.

So: Bring exofs raid engine to be usable for generic pnfs-objects use by:

* Define an exofs_comp structure that holds obj_id and credential info.

* Break up exofs_layout struct to an exofs_components structure that holds a
  possible array of exofs_comp and the array of devices + the size of the
  arrays.

* Add a "comps" parameter to get_io_state() that specifies the ids creds
  and device array to use for each IO.

  This enables to keep the layout global, but the device-table view, creds
  and IDs at the inode level. It only adds two 64bit to each inode, since
  some of these members already existed in another form.

* ios raid engine now access layout-info and comps-info through the passed
  pointers. Everything is pre-prepared by caller for generic access of
  these structures and arrays.

At the exofs Level:

* Super block holds an exofs_components struct that holds the device
  array, previously in layout. The devices there are in device-table
  order. The device-array is twice bigger and repeats the device-table
  twice so now each inode's device array can point to a random device
  and have a round-robin view of the table, making it compatible to
  previous exofs versions.

* Each inode has an exofs_components struct that is initialized at
  load time, with it's own view of the device table IDs and creds.
  When doing IO this gets passed to the io_state together with the
  layout.

While preforming this change. Bugs where found where credentials with the
wrong IDs where used to access the different SB objects (super.c). As well
as some dead code. It was never noticed because the target we use does not
check the credentials.

Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
2011-08-06 19:35:32 -07:00

325 lines
10 KiB
C

/*
* Copyright (C) 2005, 2006
* Avishay Traeger (avishay@gmail.com)
* Copyright (C) 2008, 2009
* Boaz Harrosh <bharrosh@panasas.com>
*
* Copyrights for code taken from ext2:
* Copyright (C) 1992, 1993, 1994, 1995
* Remy Card (card@masi.ibp.fr)
* Laboratoire MASI - Institut Blaise Pascal
* Universite Pierre et Marie Curie (Paris VI)
* from
* linux/fs/minix/inode.c
* Copyright (C) 1991, 1992 Linus Torvalds
*
* This file is part of exofs.
*
* exofs 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. Since it is based on ext2, and the only
* valid version of GPL for the Linux kernel is version 2, the only valid
* version of GPL for exofs is version 2.
*
* exofs 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 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 <linux/backing-dev.h>
#include <linux/pnfs_osd_xdr.h>
#include "common.h"
#define EXOFS_ERR(fmt, a...) printk(KERN_ERR "exofs: " fmt, ##a)
#ifdef CONFIG_EXOFS_DEBUG
#define EXOFS_DBGMSG(fmt, a...) \
printk(KERN_NOTICE "exofs @%s:%d: " fmt, __func__, __LINE__, ##a)
#else
#define EXOFS_DBGMSG(fmt, a...) \
do { if (0) printk(fmt, ##a); } while (0)
#endif
/* u64 has problems with printk this will cast it to unsigned long long */
#define _LLU(x) (unsigned long long)(x)
struct exofs_comp {
struct osd_obj_id obj;
u8 cred[OSD_CAP_LEN];
};
struct exofs_layout {
/* Our way of looking at the data_map */
unsigned stripe_unit;
unsigned mirrors_p1;
unsigned group_width;
u64 group_depth;
unsigned group_count;
};
struct exofs_components {
unsigned numdevs; /* Num of devices in array */
/* If @single_comp == EC_SINGLE_COMP, @comps points to a single
* component. else there are @numdevs components
*/
enum EC_COMP_USAGE {
EC_SINGLE_COMP = 0, EC_MULTPLE_COMPS = 0xffffffff
} single_comp;
struct exofs_comp *comps;
struct osd_dev **ods; /* osd_dev array */
};
/*
* our extension to the in-memory superblock
*/
struct exofs_sb_info {
struct backing_dev_info bdi; /* register our bdi with VFS */
struct exofs_sb_stats s_ess; /* Written often, pre-allocate*/
int s_timeout; /* timeout for OSD operations */
uint64_t s_nextid; /* highest object ID used */
uint32_t s_numfiles; /* number of files on fs */
spinlock_t s_next_gen_lock; /* spinlock for gen # update */
u32 s_next_generation; /* next gen # to use */
atomic_t s_curr_pending; /* number of pending commands */
struct pnfs_osd_data_map data_map; /* Default raid to use
* FIXME: Needed ?
*/
struct exofs_layout layout; /* Default files layout */
struct exofs_comp one_comp; /* id & cred of partition id=0*/
struct exofs_components comps; /* comps for the partition */
struct osd_dev *_min_one_dev[1]; /* Place holder for one dev */
};
/*
* our extension to the in-memory inode
*/
struct exofs_i_info {
struct inode vfs_inode; /* normal in-memory inode */
wait_queue_head_t i_wq; /* wait queue for inode */
unsigned long i_flags; /* various atomic flags */
uint32_t i_data[EXOFS_IDATA];/*short symlink names and device #s*/
uint32_t i_dir_start_lookup; /* which page to start lookup */
uint64_t i_commit_size; /* the object's written length */
struct exofs_comp one_comp; /* same component for all devices */
struct exofs_components comps; /* inode view of the device table */
};
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 *ios, void *private);
struct exofs_io_state {
struct kref kref;
void *private;
exofs_io_done_fn done;
struct exofs_layout *layout;
struct exofs_components *comps;
/* Global read/write IO*/
loff_t offset;
unsigned long length;
void *kern_buff;
struct page **pages;
unsigned nr_pages;
unsigned pgbase;
unsigned pages_consumed;
/* Attributes */
unsigned in_attr_len;
struct osd_attr *in_attr;
unsigned out_attr_len;
struct osd_attr *out_attr;
bool reading;
/* Variable array of size numdevs */
unsigned numdevs;
struct exofs_per_dev_state {
struct osd_request *or;
struct bio *bio;
loff_t offset;
unsigned length;
unsigned dev;
} 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
*/
#define OBJ_2BCREATED 0 /* object will be created soon*/
#define OBJ_CREATED 1 /* object has been created on the osd*/
static inline int obj_2bcreated(struct exofs_i_info *oi)
{
return test_bit(OBJ_2BCREATED, &oi->i_flags);
}
static inline void set_obj_2bcreated(struct exofs_i_info *oi)
{
set_bit(OBJ_2BCREATED, &oi->i_flags);
}
static inline int obj_created(struct exofs_i_info *oi)
{
return test_bit(OBJ_CREATED, &oi->i_flags);
}
static inline void set_obj_created(struct exofs_i_info *oi)
{
set_bit(OBJ_CREATED, &oi->i_flags);
}
int __exofs_wait_obj_created(struct exofs_i_info *oi);
static inline int wait_obj_created(struct exofs_i_info *oi)
{
if (likely(obj_created(oi)))
return 0;
return __exofs_wait_obj_created(oi);
}
/*
* get to our inode from the vfs inode
*/
static inline struct exofs_i_info *exofs_i(struct inode *inode)
{
return container_of(inode, struct exofs_i_info, vfs_inode);
}
/*
* Maximum count of links to a file
*/
#define EXOFS_LINK_MAX 32000
/*************************
* function declarations *
*************************/
/* ios.c */
int exofs_get_rw_state(struct exofs_layout *layout,
struct exofs_components *comps,
bool is_reading, u64 offset, u64 length,
struct exofs_io_state **ios);
int exofs_get_io_state(struct exofs_layout *layout,
struct exofs_components *comps,
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 exofs_truncate(struct exofs_layout *layout, struct exofs_components *comps,
u64 size);
int extract_attr_from_ios(struct exofs_io_state *ios, struct osd_attr *attr);
extern const struct osd_attr g_attr_logical_length;
/* inode.c */
unsigned exofs_max_io_pages(struct exofs_layout *layout,
unsigned expected_pages);
int exofs_setattr(struct dentry *, struct iattr *);
int exofs_write_begin(struct file *file, struct address_space *mapping,
loff_t pos, unsigned len, unsigned flags,
struct page **pagep, void **fsdata);
extern struct inode *exofs_iget(struct super_block *, unsigned long);
struct inode *exofs_new_inode(struct inode *, int);
extern int exofs_write_inode(struct inode *, struct writeback_control *wbc);
extern void exofs_evict_inode(struct inode *);
/* dir.c: */
int exofs_add_link(struct dentry *, struct inode *);
ino_t exofs_inode_by_name(struct inode *, struct dentry *);
int exofs_delete_entry(struct exofs_dir_entry *, struct page *);
int exofs_make_empty(struct inode *, struct inode *);
struct exofs_dir_entry *exofs_find_entry(struct inode *, struct dentry *,
struct page **);
int exofs_empty_dir(struct inode *);
struct exofs_dir_entry *exofs_dotdot(struct inode *, struct page **);
ino_t exofs_parent_ino(struct dentry *child);
int exofs_set_link(struct inode *, struct exofs_dir_entry *, struct page *,
struct inode *);
/* super.c */
void exofs_make_credential(u8 cred_a[OSD_CAP_LEN],
const struct osd_obj_id *obj);
int exofs_sbi_write_stats(struct exofs_sb_info *sbi);
/*********************
* operation vectors *
*********************/
/* dir.c: */
extern const struct file_operations exofs_dir_operations;
/* file.c */
extern const struct inode_operations exofs_file_inode_operations;
extern const struct file_operations exofs_file_operations;
/* inode.c */
extern const struct address_space_operations exofs_aops;
/* namei.c */
extern const struct inode_operations exofs_dir_inode_operations;
extern const struct inode_operations exofs_special_inode_operations;
/* symlink.c */
extern const struct inode_operations exofs_symlink_inode_operations;
extern const struct inode_operations exofs_fast_symlink_inode_operations;
/* exofs_init_comps will initialize an exofs_components device array
* pointing to a single exofs_comp struct, and a round-robin view
* of the device table.
* The first device of each inode is the [inode->ino % num_devices]
* and the rest of the devices sequentially following where the
* first device is after the last device.
* It is assumed that the global device array at @sbi is twice
* bigger and that the device table repeats twice.
* See: exofs_read_lookup_dev_table()
*/
static inline void exofs_init_comps(struct exofs_components *comps,
struct exofs_comp *one_comp,
struct exofs_sb_info *sbi, osd_id oid)
{
unsigned dev_mod = (unsigned)oid, first_dev;
one_comp->obj.partition = sbi->one_comp.obj.partition;
one_comp->obj.id = oid;
exofs_make_credential(one_comp->cred, &one_comp->obj);
comps->numdevs = sbi->comps.numdevs;
comps->single_comp = EC_SINGLE_COMP;
comps->comps = one_comp;
/* Round robin device view of the table */
first_dev = (dev_mod * sbi->layout.mirrors_p1) % sbi->comps.numdevs;
comps->ods = sbi->comps.ods + first_dev;
}
#endif