exofs: super_operations and file_system_type
This patch ties all operation vectors into a file system superblock and registers the exofs file_system_type at module's load time. * The file system control block (AKA on-disk superblock) resides in an object with a special ID (defined in common.h). Information included in the file system control block is used to fill the in-memory superblock structure at mount time. This object is created before the file system is used by mkexofs.c It contains information such as: - The file system's magic number - The next inode number to be allocated Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
This commit is contained in:
Boaz Harrosh
531
fs/exofs/super.c
Normal file
531
fs/exofs/super.c
Normal file
@@ -0,0 +1,531 @@
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/*
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* Copyright (C) 2005, 2006
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* Avishay Traeger (avishay@gmail.com) (avishay@il.ibm.com)
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* Copyright (C) 2005, 2006
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* International Business Machines
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* Copyright (C) 2008, 2009
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* Boaz Harrosh <bharrosh@panasas.com>
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*
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* Copyrights for code taken from ext2:
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* Copyright (C) 1992, 1993, 1994, 1995
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* Remy Card (card@masi.ibp.fr)
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* Laboratoire MASI - Institut Blaise Pascal
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* Universite Pierre et Marie Curie (Paris VI)
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* from
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* linux/fs/minix/inode.c
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* Copyright (C) 1991, 1992 Linus Torvalds
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*
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* This file is part of exofs.
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*
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* exofs is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation. Since it is based on ext2, and the only
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* valid version of GPL for the Linux kernel is version 2, the only valid
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* version of GPL for exofs is version 2.
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*
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* exofs is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with exofs; if not, write to the Free Software
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* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
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*/
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#include <linux/string.h>
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#include <linux/parser.h>
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#include <linux/vfs.h>
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#include <linux/random.h>
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#include "exofs.h"
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/******************************************************************************
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* MOUNT OPTIONS
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*****************************************************************************/
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/*
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* struct to hold what we get from mount options
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*/
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struct exofs_mountopt {
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const char *dev_name;
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uint64_t pid;
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int timeout;
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};
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/*
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* exofs-specific mount-time options.
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*/
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enum { Opt_pid, Opt_to, Opt_mkfs, Opt_format, Opt_err };
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/*
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* Our mount-time options. These should ideally be 64-bit unsigned, but the
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* kernel's parsing functions do not currently support that. 32-bit should be
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* sufficient for most applications now.
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*/
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static match_table_t tokens = {
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{Opt_pid, "pid=%u"},
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{Opt_to, "to=%u"},
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{Opt_err, NULL}
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};
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/*
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* The main option parsing method. Also makes sure that all of the mandatory
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* mount options were set.
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*/
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static int parse_options(char *options, struct exofs_mountopt *opts)
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{
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char *p;
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substring_t args[MAX_OPT_ARGS];
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int option;
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bool s_pid = false;
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EXOFS_DBGMSG("parse_options %s\n", options);
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/* defaults */
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memset(opts, 0, sizeof(*opts));
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opts->timeout = BLK_DEFAULT_SG_TIMEOUT;
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while ((p = strsep(&options, ",")) != NULL) {
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int token;
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char str[32];
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if (!*p)
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continue;
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token = match_token(p, tokens, args);
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switch (token) {
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case Opt_pid:
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if (0 == match_strlcpy(str, &args[0], sizeof(str)))
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return -EINVAL;
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opts->pid = simple_strtoull(str, NULL, 0);
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if (opts->pid < EXOFS_MIN_PID) {
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EXOFS_ERR("Partition ID must be >= %u",
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EXOFS_MIN_PID);
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return -EINVAL;
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}
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s_pid = 1;
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break;
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case Opt_to:
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if (match_int(&args[0], &option))
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return -EINVAL;
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if (option <= 0) {
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EXOFS_ERR("Timout must be > 0");
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return -EINVAL;
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}
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opts->timeout = option * HZ;
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break;
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}
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}
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if (!s_pid) {
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EXOFS_ERR("Need to specify the following options:\n");
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EXOFS_ERR(" -o pid=pid_no_to_use\n");
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return -EINVAL;
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}
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return 0;
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}
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/******************************************************************************
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* INODE CACHE
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*****************************************************************************/
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/*
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* Our inode cache. Isn't it pretty?
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*/
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static struct kmem_cache *exofs_inode_cachep;
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/*
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* Allocate an inode in the cache
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*/
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static struct inode *exofs_alloc_inode(struct super_block *sb)
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{
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struct exofs_i_info *oi;
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oi = kmem_cache_alloc(exofs_inode_cachep, GFP_KERNEL);
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if (!oi)
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return NULL;
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oi->vfs_inode.i_version = 1;
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return &oi->vfs_inode;
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}
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/*
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* Remove an inode from the cache
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*/
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static void exofs_destroy_inode(struct inode *inode)
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{
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kmem_cache_free(exofs_inode_cachep, exofs_i(inode));
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}
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/*
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* Initialize the inode
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*/
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static void exofs_init_once(void *foo)
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{
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struct exofs_i_info *oi = foo;
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inode_init_once(&oi->vfs_inode);
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}
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/*
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* Create and initialize the inode cache
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*/
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static int init_inodecache(void)
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{
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exofs_inode_cachep = kmem_cache_create("exofs_inode_cache",
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sizeof(struct exofs_i_info), 0,
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SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD,
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exofs_init_once);
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if (exofs_inode_cachep == NULL)
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return -ENOMEM;
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return 0;
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}
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/*
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* Destroy the inode cache
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*/
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static void destroy_inodecache(void)
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{
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kmem_cache_destroy(exofs_inode_cachep);
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}
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/******************************************************************************
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* SUPERBLOCK FUNCTIONS
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*****************************************************************************/
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static const struct super_operations exofs_sops;
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/*
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* Write the superblock to the OSD
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*/
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static void exofs_write_super(struct super_block *sb)
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{
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struct exofs_sb_info *sbi;
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struct exofs_fscb *fscb;
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struct osd_request *or;
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struct osd_obj_id obj;
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int ret;
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fscb = kzalloc(sizeof(struct exofs_fscb), GFP_KERNEL);
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if (!fscb) {
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EXOFS_ERR("exofs_write_super: memory allocation failed.\n");
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return;
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}
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lock_kernel();
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sbi = sb->s_fs_info;
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fscb->s_nextid = cpu_to_le64(sbi->s_nextid);
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fscb->s_numfiles = cpu_to_le32(sbi->s_numfiles);
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fscb->s_magic = cpu_to_le16(sb->s_magic);
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fscb->s_newfs = 0;
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or = osd_start_request(sbi->s_dev, GFP_KERNEL);
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if (unlikely(!or)) {
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EXOFS_ERR("exofs_write_super: osd_start_request failed.\n");
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goto out;
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}
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obj.partition = sbi->s_pid;
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obj.id = EXOFS_SUPER_ID;
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ret = osd_req_write_kern(or, &obj, 0, fscb, sizeof(*fscb));
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if (unlikely(ret)) {
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EXOFS_ERR("exofs_write_super: osd_req_write_kern failed.\n");
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goto out;
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}
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ret = exofs_sync_op(or, sbi->s_timeout, sbi->s_cred);
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if (unlikely(ret)) {
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EXOFS_ERR("exofs_write_super: exofs_sync_op failed.\n");
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goto out;
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}
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sb->s_dirt = 0;
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out:
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if (or)
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osd_end_request(or);
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unlock_kernel();
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kfree(fscb);
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}
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/*
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* This function is called when the vfs is freeing the superblock. We just
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* need to free our own part.
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*/
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static void exofs_put_super(struct super_block *sb)
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{
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int num_pend;
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struct exofs_sb_info *sbi = sb->s_fs_info;
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/* make sure there are no pending commands */
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for (num_pend = atomic_read(&sbi->s_curr_pending); num_pend > 0;
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num_pend = atomic_read(&sbi->s_curr_pending)) {
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wait_queue_head_t wq;
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init_waitqueue_head(&wq);
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wait_event_timeout(wq,
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(atomic_read(&sbi->s_curr_pending) == 0),
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msecs_to_jiffies(100));
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}
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osduld_put_device(sbi->s_dev);
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kfree(sb->s_fs_info);
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sb->s_fs_info = NULL;
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}
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/*
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* Read the superblock from the OSD and fill in the fields
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*/
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static int exofs_fill_super(struct super_block *sb, void *data, int silent)
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{
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struct inode *root;
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struct exofs_mountopt *opts = data;
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struct exofs_sb_info *sbi; /*extended info */
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struct exofs_fscb fscb; /*on-disk superblock info */
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struct osd_request *or = NULL;
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struct osd_obj_id obj;
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int ret;
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sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
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if (!sbi)
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return -ENOMEM;
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sb->s_fs_info = sbi;
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/* use mount options to fill superblock */
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sbi->s_dev = osduld_path_lookup(opts->dev_name);
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if (IS_ERR(sbi->s_dev)) {
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ret = PTR_ERR(sbi->s_dev);
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sbi->s_dev = NULL;
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goto free_sbi;
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}
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sbi->s_pid = opts->pid;
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sbi->s_timeout = opts->timeout;
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/* fill in some other data by hand */
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memset(sb->s_id, 0, sizeof(sb->s_id));
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strcpy(sb->s_id, "exofs");
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sb->s_blocksize = EXOFS_BLKSIZE;
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sb->s_blocksize_bits = EXOFS_BLKSHIFT;
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sb->s_maxbytes = MAX_LFS_FILESIZE;
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atomic_set(&sbi->s_curr_pending, 0);
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sb->s_bdev = NULL;
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sb->s_dev = 0;
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/* read data from on-disk superblock object */
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obj.partition = sbi->s_pid;
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obj.id = EXOFS_SUPER_ID;
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exofs_make_credential(sbi->s_cred, &obj);
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or = osd_start_request(sbi->s_dev, GFP_KERNEL);
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if (unlikely(!or)) {
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if (!silent)
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EXOFS_ERR(
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"exofs_fill_super: osd_start_request failed.\n");
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ret = -ENOMEM;
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goto free_sbi;
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}
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ret = osd_req_read_kern(or, &obj, 0, &fscb, sizeof(fscb));
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if (unlikely(ret)) {
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if (!silent)
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EXOFS_ERR(
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"exofs_fill_super: osd_req_read_kern failed.\n");
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ret = -ENOMEM;
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goto free_sbi;
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}
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ret = exofs_sync_op(or, sbi->s_timeout, sbi->s_cred);
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if (unlikely(ret)) {
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if (!silent)
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EXOFS_ERR("exofs_fill_super: exofs_sync_op failed.\n");
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ret = -EIO;
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goto free_sbi;
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}
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sb->s_magic = le16_to_cpu(fscb.s_magic);
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sbi->s_nextid = le64_to_cpu(fscb.s_nextid);
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sbi->s_numfiles = le32_to_cpu(fscb.s_numfiles);
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/* make sure what we read from the object store is correct */
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if (sb->s_magic != EXOFS_SUPER_MAGIC) {
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if (!silent)
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EXOFS_ERR("ERROR: Bad magic value\n");
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ret = -EINVAL;
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goto free_sbi;
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}
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/* start generation numbers from a random point */
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get_random_bytes(&sbi->s_next_generation, sizeof(u32));
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spin_lock_init(&sbi->s_next_gen_lock);
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/* set up operation vectors */
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sb->s_op = &exofs_sops;
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root = exofs_iget(sb, EXOFS_ROOT_ID - EXOFS_OBJ_OFF);
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if (IS_ERR(root)) {
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EXOFS_ERR("ERROR: exofs_iget failed\n");
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ret = PTR_ERR(root);
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goto free_sbi;
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}
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sb->s_root = d_alloc_root(root);
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if (!sb->s_root) {
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iput(root);
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EXOFS_ERR("ERROR: get root inode failed\n");
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ret = -ENOMEM;
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goto free_sbi;
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}
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if (!S_ISDIR(root->i_mode)) {
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dput(sb->s_root);
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sb->s_root = NULL;
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EXOFS_ERR("ERROR: corrupt root inode (mode = %hd)\n",
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root->i_mode);
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ret = -EINVAL;
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goto free_sbi;
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}
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ret = 0;
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out:
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if (or)
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osd_end_request(or);
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return ret;
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free_sbi:
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osduld_put_device(sbi->s_dev); /* NULL safe */
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kfree(sbi);
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goto out;
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}
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/*
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* Set up the superblock (calls exofs_fill_super eventually)
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*/
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static int exofs_get_sb(struct file_system_type *type,
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int flags, const char *dev_name,
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void *data, struct vfsmount *mnt)
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{
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struct exofs_mountopt opts;
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int ret;
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ret = parse_options(data, &opts);
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if (ret)
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return ret;
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opts.dev_name = dev_name;
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return get_sb_nodev(type, flags, &opts, exofs_fill_super, mnt);
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}
|
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|
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/*
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* Return information about the file system state in the buffer. This is used
|
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* by the 'df' command, for example.
|
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*/
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static int exofs_statfs(struct dentry *dentry, struct kstatfs *buf)
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{
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struct super_block *sb = dentry->d_sb;
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struct exofs_sb_info *sbi = sb->s_fs_info;
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struct osd_obj_id obj = {sbi->s_pid, 0};
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struct osd_attr attrs[] = {
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ATTR_DEF(OSD_APAGE_PARTITION_QUOTAS,
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OSD_ATTR_PQ_CAPACITY_QUOTA, sizeof(__be64)),
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ATTR_DEF(OSD_APAGE_PARTITION_INFORMATION,
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OSD_ATTR_PI_USED_CAPACITY, sizeof(__be64)),
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};
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uint64_t capacity = ULLONG_MAX;
|
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uint64_t used = ULLONG_MAX;
|
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struct osd_request *or;
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uint8_t cred_a[OSD_CAP_LEN];
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int ret;
|
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|
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/* get used/capacity attributes */
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exofs_make_credential(cred_a, &obj);
|
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|
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or = osd_start_request(sbi->s_dev, GFP_KERNEL);
|
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if (unlikely(!or)) {
|
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EXOFS_DBGMSG("exofs_statfs: osd_start_request failed.\n");
|
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return -ENOMEM;
|
||||
}
|
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|
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osd_req_get_attributes(or, &obj);
|
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osd_req_add_get_attr_list(or, attrs, ARRAY_SIZE(attrs));
|
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ret = exofs_sync_op(or, sbi->s_timeout, cred_a);
|
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if (unlikely(ret))
|
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goto out;
|
||||
|
||||
ret = extract_attr_from_req(or, &attrs[0]);
|
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if (likely(!ret))
|
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capacity = get_unaligned_be64(attrs[0].val_ptr);
|
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else
|
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EXOFS_DBGMSG("exofs_statfs: get capacity failed.\n");
|
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|
||||
ret = extract_attr_from_req(or, &attrs[1]);
|
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if (likely(!ret))
|
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used = get_unaligned_be64(attrs[1].val_ptr);
|
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else
|
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EXOFS_DBGMSG("exofs_statfs: get used-space failed.\n");
|
||||
|
||||
/* fill in the stats buffer */
|
||||
buf->f_type = EXOFS_SUPER_MAGIC;
|
||||
buf->f_bsize = EXOFS_BLKSIZE;
|
||||
buf->f_blocks = (capacity >> EXOFS_BLKSHIFT);
|
||||
buf->f_bfree = ((capacity - used) >> EXOFS_BLKSHIFT);
|
||||
buf->f_bavail = buf->f_bfree;
|
||||
buf->f_files = sbi->s_numfiles;
|
||||
buf->f_ffree = EXOFS_MAX_ID - sbi->s_numfiles;
|
||||
buf->f_namelen = EXOFS_NAME_LEN;
|
||||
|
||||
out:
|
||||
osd_end_request(or);
|
||||
return ret;
|
||||
}
|
||||
|
||||
static const struct super_operations exofs_sops = {
|
||||
.alloc_inode = exofs_alloc_inode,
|
||||
.destroy_inode = exofs_destroy_inode,
|
||||
.write_inode = exofs_write_inode,
|
||||
.delete_inode = exofs_delete_inode,
|
||||
.put_super = exofs_put_super,
|
||||
.write_super = exofs_write_super,
|
||||
.statfs = exofs_statfs,
|
||||
};
|
||||
|
||||
/******************************************************************************
|
||||
* INSMOD/RMMOD
|
||||
*****************************************************************************/
|
||||
|
||||
/*
|
||||
* struct that describes this file system
|
||||
*/
|
||||
static struct file_system_type exofs_type = {
|
||||
.owner = THIS_MODULE,
|
||||
.name = "exofs",
|
||||
.get_sb = exofs_get_sb,
|
||||
.kill_sb = generic_shutdown_super,
|
||||
};
|
||||
|
||||
static int __init init_exofs(void)
|
||||
{
|
||||
int err;
|
||||
|
||||
err = init_inodecache();
|
||||
if (err)
|
||||
goto out;
|
||||
|
||||
err = register_filesystem(&exofs_type);
|
||||
if (err)
|
||||
goto out_d;
|
||||
|
||||
return 0;
|
||||
out_d:
|
||||
destroy_inodecache();
|
||||
out:
|
||||
return err;
|
||||
}
|
||||
|
||||
static void __exit exit_exofs(void)
|
||||
{
|
||||
unregister_filesystem(&exofs_type);
|
||||
destroy_inodecache();
|
||||
}
|
||||
|
||||
MODULE_AUTHOR("Avishay Traeger <avishay@gmail.com>");
|
||||
MODULE_DESCRIPTION("exofs");
|
||||
MODULE_LICENSE("GPL");
|
||||
|
||||
module_init(init_exofs)
|
||||
module_exit(exit_exofs)
|
||||
Reference in New Issue
Block a user