/* * Copyright (C) 2005, 2006 * Avishay Traeger (avishay@gmail.com) (avishay@il.ibm.com) * Copyright (C) 2005, 2006 * International Business Machines * 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 */ #include <linux/string.h> #include <linux/parser.h> #include <linux/vfs.h> #include <linux/random.h> #include <linux/exportfs.h> #include "exofs.h" /****************************************************************************** * MOUNT OPTIONS *****************************************************************************/ /* * struct to hold what we get from mount options */ struct exofs_mountopt { const char *dev_name; uint64_t pid; int timeout; }; /* * exofs-specific mount-time options. */ enum { Opt_pid, Opt_to, Opt_mkfs, Opt_format, Opt_err }; /* * Our mount-time options. These should ideally be 64-bit unsigned, but the * kernel's parsing functions do not currently support that. 32-bit should be * sufficient for most applications now. */ static match_table_t tokens = { {Opt_pid, "pid=%u"}, {Opt_to, "to=%u"}, {Opt_err, NULL} }; /* * The main option parsing method. Also makes sure that all of the mandatory * mount options were set. */ static int parse_options(char *options, struct exofs_mountopt *opts) { char *p; substring_t args[MAX_OPT_ARGS]; int option; bool s_pid = false; EXOFS_DBGMSG("parse_options %s\n", options); /* defaults */ memset(opts, 0, sizeof(*opts)); opts->timeout = BLK_DEFAULT_SG_TIMEOUT; while ((p = strsep(&options, ",")) != NULL) { int token; char str[32]; if (!*p) continue; token = match_token(p, tokens, args); switch (token) { case Opt_pid: if (0 == match_strlcpy(str, &args[0], sizeof(str))) return -EINVAL; opts->pid = simple_strtoull(str, NULL, 0); if (opts->pid < EXOFS_MIN_PID) { EXOFS_ERR("Partition ID must be >= %u", EXOFS_MIN_PID); return -EINVAL; } s_pid = 1; break; case Opt_to: if (match_int(&args[0], &option)) return -EINVAL; if (option <= 0) { EXOFS_ERR("Timout must be > 0"); return -EINVAL; } opts->timeout = option * HZ; break; } } if (!s_pid) { EXOFS_ERR("Need to specify the following options:\n"); EXOFS_ERR(" -o pid=pid_no_to_use\n"); return -EINVAL; } return 0; } /****************************************************************************** * INODE CACHE *****************************************************************************/ /* * Our inode cache. Isn't it pretty? */ static struct kmem_cache *exofs_inode_cachep; /* * Allocate an inode in the cache */ static struct inode *exofs_alloc_inode(struct super_block *sb) { struct exofs_i_info *oi; oi = kmem_cache_alloc(exofs_inode_cachep, GFP_KERNEL); if (!oi) return NULL; oi->vfs_inode.i_version = 1; return &oi->vfs_inode; } /* * Remove an inode from the cache */ static void exofs_destroy_inode(struct inode *inode) { kmem_cache_free(exofs_inode_cachep, exofs_i(inode)); } /* * Initialize the inode */ static void exofs_init_once(void *foo) { struct exofs_i_info *oi = foo; inode_init_once(&oi->vfs_inode); } /* * Create and initialize the inode cache */ static int init_inodecache(void) { exofs_inode_cachep = kmem_cache_create("exofs_inode_cache", sizeof(struct exofs_i_info), 0, SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, exofs_init_once); if (exofs_inode_cachep == NULL) return -ENOMEM; return 0; } /* * Destroy the inode cache */ static void destroy_inodecache(void) { kmem_cache_destroy(exofs_inode_cachep); } /****************************************************************************** * SUPERBLOCK FUNCTIONS *****************************************************************************/ static const struct super_operations exofs_sops; static const struct export_operations exofs_export_ops; /* * Write the superblock to the OSD */ static int exofs_sync_fs(struct super_block *sb, int wait) { struct exofs_sb_info *sbi; struct exofs_fscb *fscb; struct osd_request *or; struct osd_obj_id obj; int ret = -ENOMEM; fscb = kzalloc(sizeof(struct exofs_fscb), GFP_KERNEL); if (!fscb) { EXOFS_ERR("exofs_write_super: memory allocation failed.\n"); return -ENOMEM; } lock_super(sb); lock_kernel(); sbi = sb->s_fs_info; fscb->s_nextid = cpu_to_le64(sbi->s_nextid); fscb->s_numfiles = cpu_to_le32(sbi->s_numfiles); fscb->s_magic = cpu_to_le16(sb->s_magic); fscb->s_newfs = 0; or = osd_start_request(sbi->s_dev, GFP_KERNEL); if (unlikely(!or)) { EXOFS_ERR("exofs_write_super: osd_start_request failed.\n"); goto out; } obj.partition = sbi->s_pid; obj.id = EXOFS_SUPER_ID; ret = osd_req_write_kern(or, &obj, 0, fscb, sizeof(*fscb)); if (unlikely(ret)) { EXOFS_ERR("exofs_write_super: osd_req_write_kern failed.\n"); goto out; } ret = exofs_sync_op(or, sbi->s_timeout, sbi->s_cred); if (unlikely(ret)) { EXOFS_ERR("exofs_write_super: exofs_sync_op failed.\n"); goto out; } sb->s_dirt = 0; out: if (or) osd_end_request(or); unlock_kernel(); unlock_super(sb); kfree(fscb); return ret; } static void exofs_write_super(struct super_block *sb) { if (!(sb->s_flags & MS_RDONLY)) exofs_sync_fs(sb, 1); else sb->s_dirt = 0; } /* * This function is called when the vfs is freeing the superblock. We just * need to free our own part. */ static void exofs_put_super(struct super_block *sb) { int num_pend; struct exofs_sb_info *sbi = sb->s_fs_info; lock_kernel(); if (sb->s_dirt) exofs_write_super(sb); /* make sure there are no pending commands */ for (num_pend = atomic_read(&sbi->s_curr_pending); num_pend > 0; num_pend = atomic_read(&sbi->s_curr_pending)) { wait_queue_head_t wq; init_waitqueue_head(&wq); wait_event_timeout(wq, (atomic_read(&sbi->s_curr_pending) == 0), msecs_to_jiffies(100)); } osduld_put_device(sbi->s_dev); kfree(sb->s_fs_info); sb->s_fs_info = NULL; unlock_kernel(); } /* * Read the superblock from the OSD and fill in the fields */ static int exofs_fill_super(struct super_block *sb, void *data, int silent) { struct inode *root; struct exofs_mountopt *opts = data; struct exofs_sb_info *sbi; /*extended info */ struct exofs_fscb fscb; /*on-disk superblock info */ struct osd_request *or = NULL; struct osd_obj_id obj; int ret; sbi = kzalloc(sizeof(*sbi), GFP_KERNEL); if (!sbi) return -ENOMEM; sb->s_fs_info = sbi; /* use mount options to fill superblock */ sbi->s_dev = osduld_path_lookup(opts->dev_name); if (IS_ERR(sbi->s_dev)) { ret = PTR_ERR(sbi->s_dev); sbi->s_dev = NULL; goto free_sbi; } sbi->s_pid = opts->pid; sbi->s_timeout = opts->timeout; /* fill in some other data by hand */ memset(sb->s_id, 0, sizeof(sb->s_id)); strcpy(sb->s_id, "exofs"); sb->s_blocksize = EXOFS_BLKSIZE; sb->s_blocksize_bits = EXOFS_BLKSHIFT; sb->s_maxbytes = MAX_LFS_FILESIZE; atomic_set(&sbi->s_curr_pending, 0); sb->s_bdev = NULL; sb->s_dev = 0; /* read data from on-disk superblock object */ obj.partition = sbi->s_pid; obj.id = EXOFS_SUPER_ID; exofs_make_credential(sbi->s_cred, &obj); or = osd_start_request(sbi->s_dev, GFP_KERNEL); if (unlikely(!or)) { if (!silent) EXOFS_ERR( "exofs_fill_super: osd_start_request failed.\n"); ret = -ENOMEM; goto free_sbi; } ret = osd_req_read_kern(or, &obj, 0, &fscb, sizeof(fscb)); if (unlikely(ret)) { if (!silent) EXOFS_ERR( "exofs_fill_super: osd_req_read_kern failed.\n"); ret = -ENOMEM; goto free_sbi; } ret = exofs_sync_op(or, sbi->s_timeout, sbi->s_cred); if (unlikely(ret)) { if (!silent) EXOFS_ERR("exofs_fill_super: exofs_sync_op failed.\n"); ret = -EIO; goto free_sbi; } sb->s_magic = le16_to_cpu(fscb.s_magic); sbi->s_nextid = le64_to_cpu(fscb.s_nextid); sbi->s_numfiles = le32_to_cpu(fscb.s_numfiles); /* make sure what we read from the object store is correct */ if (sb->s_magic != EXOFS_SUPER_MAGIC) { if (!silent) EXOFS_ERR("ERROR: Bad magic value\n"); ret = -EINVAL; goto free_sbi; } /* start generation numbers from a random point */ get_random_bytes(&sbi->s_next_generation, sizeof(u32)); spin_lock_init(&sbi->s_next_gen_lock); /* set up operation vectors */ sb->s_op = &exofs_sops; sb->s_export_op = &exofs_export_ops; root = exofs_iget(sb, EXOFS_ROOT_ID - EXOFS_OBJ_OFF); if (IS_ERR(root)) { EXOFS_ERR("ERROR: exofs_iget failed\n"); ret = PTR_ERR(root); goto free_sbi; } sb->s_root = d_alloc_root(root); if (!sb->s_root) { iput(root); EXOFS_ERR("ERROR: get root inode failed\n"); ret = -ENOMEM; goto free_sbi; } if (!S_ISDIR(root->i_mode)) { dput(sb->s_root); sb->s_root = NULL; EXOFS_ERR("ERROR: corrupt root inode (mode = %hd)\n", root->i_mode); ret = -EINVAL; goto free_sbi; } ret = 0; out: if (or) osd_end_request(or); return ret; free_sbi: osduld_put_device(sbi->s_dev); /* NULL safe */ kfree(sbi); goto out; } /* * Set up the superblock (calls exofs_fill_super eventually) */ static int exofs_get_sb(struct file_system_type *type, int flags, const char *dev_name, void *data, struct vfsmount *mnt) { struct exofs_mountopt opts; int ret; ret = parse_options(data, &opts); if (ret) return ret; opts.dev_name = dev_name; return get_sb_nodev(type, flags, &opts, exofs_fill_super, mnt); } /* * Return information about the file system state in the buffer. This is used * by the 'df' command, for example. */ static int exofs_statfs(struct dentry *dentry, struct kstatfs *buf) { struct super_block *sb = dentry->d_sb; struct exofs_sb_info *sbi = sb->s_fs_info; struct osd_obj_id obj = {sbi->s_pid, 0}; struct osd_attr attrs[] = { ATTR_DEF(OSD_APAGE_PARTITION_QUOTAS, OSD_ATTR_PQ_CAPACITY_QUOTA, sizeof(__be64)), ATTR_DEF(OSD_APAGE_PARTITION_INFORMATION, OSD_ATTR_PI_USED_CAPACITY, sizeof(__be64)), }; uint64_t capacity = ULLONG_MAX; uint64_t used = ULLONG_MAX; struct osd_request *or; uint8_t cred_a[OSD_CAP_LEN]; int ret; /* get used/capacity attributes */ exofs_make_credential(cred_a, &obj); or = osd_start_request(sbi->s_dev, GFP_KERNEL); if (unlikely(!or)) { EXOFS_DBGMSG("exofs_statfs: osd_start_request failed.\n"); return -ENOMEM; } osd_req_get_attributes(or, &obj); osd_req_add_get_attr_list(or, attrs, ARRAY_SIZE(attrs)); ret = exofs_sync_op(or, sbi->s_timeout, cred_a); if (unlikely(ret)) goto out; ret = extract_attr_from_req(or, &attrs[0]); if (likely(!ret)) capacity = get_unaligned_be64(attrs[0].val_ptr); else EXOFS_DBGMSG("exofs_statfs: get capacity failed.\n"); ret = extract_attr_from_req(or, &attrs[1]); if (likely(!ret)) used = get_unaligned_be64(attrs[1].val_ptr); else 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, .sync_fs = exofs_sync_fs, .statfs = exofs_statfs, }; /****************************************************************************** * EXPORT OPERATIONS *****************************************************************************/ struct dentry *exofs_get_parent(struct dentry *child) { unsigned long ino = exofs_parent_ino(child); if (!ino) return NULL; return d_obtain_alias(exofs_iget(child->d_inode->i_sb, ino)); } static struct inode *exofs_nfs_get_inode(struct super_block *sb, u64 ino, u32 generation) { struct inode *inode; inode = exofs_iget(sb, ino); if (IS_ERR(inode)) return ERR_CAST(inode); if (generation && inode->i_generation != generation) { /* we didn't find the right inode.. */ iput(inode); return ERR_PTR(-ESTALE); } return inode; } static struct dentry *exofs_fh_to_dentry(struct super_block *sb, struct fid *fid, int fh_len, int fh_type) { return generic_fh_to_dentry(sb, fid, fh_len, fh_type, exofs_nfs_get_inode); } static struct dentry *exofs_fh_to_parent(struct super_block *sb, struct fid *fid, int fh_len, int fh_type) { return generic_fh_to_parent(sb, fid, fh_len, fh_type, exofs_nfs_get_inode); } static const struct export_operations exofs_export_ops = { .fh_to_dentry = exofs_fh_to_dentry, .fh_to_parent = exofs_fh_to_parent, .get_parent = exofs_get_parent, }; /****************************************************************************** * 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)