/* * Copyright (C) 2007 Oracle. All rights reserved. * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public * License v2 as published by the Free Software Foundation. * * 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 021110-1307, USA. */ #include <linux/blkdev.h> #include <linux/module.h> #include <linux/buffer_head.h> #include <linux/fs.h> #include <linux/pagemap.h> #include <linux/highmem.h> #include <linux/time.h> #include <linux/init.h> #include <linux/string.h> #include <linux/smp_lock.h> #include <linux/backing-dev.h> #include <linux/mount.h> #include <linux/mpage.h> #include <linux/swap.h> #include <linux/writeback.h> #include <linux/statfs.h> #include <linux/compat.h> #include <linux/parser.h> #include <linux/ctype.h> #include <linux/namei.h> #include <linux/miscdevice.h> #include <linux/magic.h> #include "compat.h" #include "ctree.h" #include "disk-io.h" #include "transaction.h" #include "btrfs_inode.h" #include "ioctl.h" #include "print-tree.h" #include "xattr.h" #include "volumes.h" #include "version.h" #include "export.h" #include "compression.h" static struct super_operations btrfs_super_ops; static void btrfs_put_super(struct super_block *sb) { struct btrfs_root *root = btrfs_sb(sb); int ret; ret = close_ctree(root); sb->s_fs_info = NULL; } enum { Opt_degraded, Opt_subvol, Opt_device, Opt_nodatasum, Opt_nodatacow, Opt_max_extent, Opt_max_inline, Opt_alloc_start, Opt_nobarrier, Opt_ssd, Opt_thread_pool, Opt_noacl, Opt_compress, Opt_err, }; static match_table_t tokens = { {Opt_degraded, "degraded"}, {Opt_subvol, "subvol=%s"}, {Opt_device, "device=%s"}, {Opt_nodatasum, "nodatasum"}, {Opt_nodatacow, "nodatacow"}, {Opt_nobarrier, "nobarrier"}, {Opt_max_extent, "max_extent=%s"}, {Opt_max_inline, "max_inline=%s"}, {Opt_alloc_start, "alloc_start=%s"}, {Opt_thread_pool, "thread_pool=%d"}, {Opt_compress, "compress"}, {Opt_ssd, "ssd"}, {Opt_noacl, "noacl"}, {Opt_err, NULL}, }; u64 btrfs_parse_size(char *str) { u64 res; int mult = 1; char *end; char last; res = simple_strtoul(str, &end, 10); last = end[0]; if (isalpha(last)) { last = tolower(last); switch (last) { case 'g': mult *= 1024; case 'm': mult *= 1024; case 'k': mult *= 1024; } res = res * mult; } return res; } /* * Regular mount options parser. Everything that is needed only when * reading in a new superblock is parsed here. */ int btrfs_parse_options(struct btrfs_root *root, char *options) { struct btrfs_fs_info *info = root->fs_info; substring_t args[MAX_OPT_ARGS]; char *p, *num; int intarg; if (!options) return 0; /* * strsep changes the string, duplicate it because parse_options * gets called twice */ options = kstrdup(options, GFP_NOFS); if (!options) return -ENOMEM; while ((p = strsep(&options, ",")) != NULL) { int token; if (!*p) continue; token = match_token(p, tokens, args); switch (token) { case Opt_degraded: printk(KERN_INFO "btrfs: allowing degraded mounts\n"); btrfs_set_opt(info->mount_opt, DEGRADED); break; case Opt_subvol: case Opt_device: /* * These are parsed by btrfs_parse_early_options * and can be happily ignored here. */ break; case Opt_nodatasum: printk(KERN_INFO "btrfs: setting nodatacsum\n"); btrfs_set_opt(info->mount_opt, NODATASUM); break; case Opt_nodatacow: printk(KERN_INFO "btrfs: setting nodatacow\n"); btrfs_set_opt(info->mount_opt, NODATACOW); btrfs_set_opt(info->mount_opt, NODATASUM); break; case Opt_compress: printk(KERN_INFO "btrfs: use compression\n"); btrfs_set_opt(info->mount_opt, COMPRESS); break; case Opt_ssd: printk(KERN_INFO "btrfs: use ssd allocation scheme\n"); btrfs_set_opt(info->mount_opt, SSD); break; case Opt_nobarrier: printk(KERN_INFO "btrfs: turning off barriers\n"); btrfs_set_opt(info->mount_opt, NOBARRIER); break; case Opt_thread_pool: intarg = 0; match_int(&args[0], &intarg); if (intarg) { info->thread_pool_size = intarg; printk(KERN_INFO "btrfs: thread pool %d\n", info->thread_pool_size); } break; case Opt_max_extent: num = match_strdup(&args[0]); if (num) { info->max_extent = btrfs_parse_size(num); kfree(num); info->max_extent = max_t(u64, info->max_extent, root->sectorsize); printk(KERN_INFO "btrfs: max_extent at %llu\n", info->max_extent); } break; case Opt_max_inline: num = match_strdup(&args[0]); if (num) { info->max_inline = btrfs_parse_size(num); kfree(num); if (info->max_inline) { info->max_inline = max_t(u64, info->max_inline, root->sectorsize); } printk(KERN_INFO "btrfs: max_inline at %llu\n", info->max_inline); } break; case Opt_alloc_start: num = match_strdup(&args[0]); if (num) { info->alloc_start = btrfs_parse_size(num); kfree(num); printk(KERN_INFO "btrfs: allocations start at %llu\n", info->alloc_start); } break; case Opt_noacl: root->fs_info->sb->s_flags &= ~MS_POSIXACL; break; default: break; } } kfree(options); return 0; } /* * Parse mount options that are required early in the mount process. * * All other options will be parsed on much later in the mount process and * only when we need to allocate a new super block. */ static int btrfs_parse_early_options(const char *options, fmode_t flags, void *holder, char **subvol_name, struct btrfs_fs_devices **fs_devices) { substring_t args[MAX_OPT_ARGS]; char *opts, *p; int error = 0; if (!options) goto out; /* * strsep changes the string, duplicate it because parse_options * gets called twice */ opts = kstrdup(options, GFP_KERNEL); if (!opts) return -ENOMEM; while ((p = strsep(&opts, ",")) != NULL) { int token; if (!*p) continue; token = match_token(p, tokens, args); switch (token) { case Opt_subvol: *subvol_name = match_strdup(&args[0]); break; case Opt_device: error = btrfs_scan_one_device(match_strdup(&args[0]), flags, holder, fs_devices); if (error) goto out_free_opts; break; default: break; } } out_free_opts: kfree(opts); out: /* * If no subvolume name is specified we use the default one. Allocate * a copy of the string "." here so that code later in the * mount path doesn't care if it's the default volume or another one. */ if (!*subvol_name) { *subvol_name = kstrdup(".", GFP_KERNEL); if (!*subvol_name) return -ENOMEM; } return error; } static int btrfs_fill_super(struct super_block *sb, struct btrfs_fs_devices *fs_devices, void *data, int silent) { struct inode *inode; struct dentry *root_dentry; struct btrfs_super_block *disk_super; struct btrfs_root *tree_root; struct btrfs_inode *bi; int err; sb->s_maxbytes = MAX_LFS_FILESIZE; sb->s_magic = BTRFS_SUPER_MAGIC; sb->s_op = &btrfs_super_ops; sb->s_export_op = &btrfs_export_ops; sb->s_xattr = btrfs_xattr_handlers; sb->s_time_gran = 1; sb->s_flags |= MS_POSIXACL; tree_root = open_ctree(sb, fs_devices, (char *)data); if (IS_ERR(tree_root)) { printk("btrfs: open_ctree failed\n"); return PTR_ERR(tree_root); } sb->s_fs_info = tree_root; disk_super = &tree_root->fs_info->super_copy; inode = btrfs_iget_locked(sb, BTRFS_FIRST_FREE_OBJECTID, tree_root->fs_info->fs_root); bi = BTRFS_I(inode); bi->location.objectid = inode->i_ino; bi->location.offset = 0; bi->root = tree_root->fs_info->fs_root; btrfs_set_key_type(&bi->location, BTRFS_INODE_ITEM_KEY); if (!inode) { err = -ENOMEM; goto fail_close; } if (inode->i_state & I_NEW) { btrfs_read_locked_inode(inode); unlock_new_inode(inode); } root_dentry = d_alloc_root(inode); if (!root_dentry) { iput(inode); err = -ENOMEM; goto fail_close; } #if 0 /* this does the super kobj at the same time */ err = btrfs_sysfs_add_super(tree_root->fs_info); if (err) goto fail_close; #endif sb->s_root = root_dentry; save_mount_options(sb, data); return 0; fail_close: close_ctree(tree_root); return err; } int btrfs_sync_fs(struct super_block *sb, int wait) { struct btrfs_trans_handle *trans; struct btrfs_root *root; int ret; root = btrfs_sb(sb); if (sb->s_flags & MS_RDONLY) return 0; sb->s_dirt = 0; if (!wait) { filemap_flush(root->fs_info->btree_inode->i_mapping); return 0; } btrfs_start_delalloc_inodes(root); btrfs_wait_ordered_extents(root, 0); trans = btrfs_start_transaction(root, 1); ret = btrfs_commit_transaction(trans, root); sb->s_dirt = 0; return ret; } static void btrfs_write_super(struct super_block *sb) { sb->s_dirt = 0; } static int btrfs_test_super(struct super_block *s, void *data) { struct btrfs_fs_devices *test_fs_devices = data; struct btrfs_root *root = btrfs_sb(s); return root->fs_info->fs_devices == test_fs_devices; } /* * Find a superblock for the given device / mount point. * * Note: This is based on get_sb_bdev from fs/super.c with a few additions * for multiple device setup. Make sure to keep it in sync. */ static int btrfs_get_sb(struct file_system_type *fs_type, int flags, const char *dev_name, void *data, struct vfsmount *mnt) { char *subvol_name = NULL; struct block_device *bdev = NULL; struct super_block *s; struct dentry *root; struct btrfs_fs_devices *fs_devices = NULL; fmode_t mode = FMODE_READ; int error = 0; if (!(flags & MS_RDONLY)) mode |= FMODE_WRITE; error = btrfs_parse_early_options(data, mode, fs_type, &subvol_name, &fs_devices); if (error) return error; error = btrfs_scan_one_device(dev_name, mode, fs_type, &fs_devices); if (error) goto error_free_subvol_name; error = btrfs_open_devices(fs_devices, mode, fs_type); if (error) goto error_free_subvol_name; if (!(flags & MS_RDONLY) && fs_devices->rw_devices == 0) { error = -EACCES; goto error_close_devices; } bdev = fs_devices->latest_bdev; s = sget(fs_type, btrfs_test_super, set_anon_super, fs_devices); if (IS_ERR(s)) goto error_s; if (s->s_root) { if ((flags ^ s->s_flags) & MS_RDONLY) { up_write(&s->s_umount); deactivate_super(s); error = -EBUSY; goto error_close_devices; } btrfs_close_devices(fs_devices); } else { char b[BDEVNAME_SIZE]; s->s_flags = flags; strlcpy(s->s_id, bdevname(bdev, b), sizeof(s->s_id)); error = btrfs_fill_super(s, fs_devices, data, flags & MS_SILENT ? 1 : 0); if (error) { up_write(&s->s_umount); deactivate_super(s); goto error_free_subvol_name; } btrfs_sb(s)->fs_info->bdev_holder = fs_type; s->s_flags |= MS_ACTIVE; } if (!strcmp(subvol_name, ".")) root = dget(s->s_root); else { mutex_lock(&s->s_root->d_inode->i_mutex); root = lookup_one_len(subvol_name, s->s_root, strlen(subvol_name)); mutex_unlock(&s->s_root->d_inode->i_mutex); if (IS_ERR(root)) { up_write(&s->s_umount); deactivate_super(s); error = PTR_ERR(root); goto error_free_subvol_name; } if (!root->d_inode) { dput(root); up_write(&s->s_umount); deactivate_super(s); error = -ENXIO; goto error_free_subvol_name; } } mnt->mnt_sb = s; mnt->mnt_root = root; kfree(subvol_name); return 0; error_s: error = PTR_ERR(s); error_close_devices: btrfs_close_devices(fs_devices); error_free_subvol_name: kfree(subvol_name); return error; } static int btrfs_remount(struct super_block *sb, int *flags, char *data) { struct btrfs_root *root = btrfs_sb(sb); int ret; ret = btrfs_parse_options(root, data); if (ret) return -EINVAL; if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY)) return 0; if (*flags & MS_RDONLY) { sb->s_flags |= MS_RDONLY; ret = btrfs_commit_super(root); WARN_ON(ret); } else { if (root->fs_info->fs_devices->rw_devices == 0) return -EACCES; if (btrfs_super_log_root(&root->fs_info->super_copy) != 0) return -EINVAL; ret = btrfs_cleanup_reloc_trees(root); WARN_ON(ret); ret = btrfs_cleanup_fs_roots(root->fs_info); WARN_ON(ret); sb->s_flags &= ~MS_RDONLY; } return 0; } static int btrfs_statfs(struct dentry *dentry, struct kstatfs *buf) { struct btrfs_root *root = btrfs_sb(dentry->d_sb); struct btrfs_super_block *disk_super = &root->fs_info->super_copy; int bits = dentry->d_sb->s_blocksize_bits; __be32 *fsid = (__be32 *)root->fs_info->fsid; buf->f_namelen = BTRFS_NAME_LEN; buf->f_blocks = btrfs_super_total_bytes(disk_super) >> bits; buf->f_bfree = buf->f_blocks - (btrfs_super_bytes_used(disk_super) >> bits); buf->f_bavail = buf->f_bfree; buf->f_bsize = dentry->d_sb->s_blocksize; buf->f_type = BTRFS_SUPER_MAGIC; /* We treat it as constant endianness (it doesn't matter _which_) because we want the fsid to come out the same whether mounted on a big-endian or little-endian host */ buf->f_fsid.val[0] = be32_to_cpu(fsid[0]) ^ be32_to_cpu(fsid[2]); buf->f_fsid.val[1] = be32_to_cpu(fsid[1]) ^ be32_to_cpu(fsid[3]); /* Mask in the root object ID too, to disambiguate subvols */ buf->f_fsid.val[0] ^= BTRFS_I(dentry->d_inode)->root->objectid >> 32; buf->f_fsid.val[1] ^= BTRFS_I(dentry->d_inode)->root->objectid; return 0; } static struct file_system_type btrfs_fs_type = { .owner = THIS_MODULE, .name = "btrfs", .get_sb = btrfs_get_sb, .kill_sb = kill_anon_super, .fs_flags = FS_REQUIRES_DEV, }; /* * used by btrfsctl to scan devices when no FS is mounted */ static long btrfs_control_ioctl(struct file *file, unsigned int cmd, unsigned long arg) { struct btrfs_ioctl_vol_args *vol; struct btrfs_fs_devices *fs_devices; int ret = -ENOTTY; if (!capable(CAP_SYS_ADMIN)) return -EPERM; vol = kmalloc(sizeof(*vol), GFP_KERNEL); if (!vol) return -ENOMEM; if (copy_from_user(vol, (void __user *)arg, sizeof(*vol))) { ret = -EFAULT; goto out; } switch (cmd) { case BTRFS_IOC_SCAN_DEV: ret = btrfs_scan_one_device(vol->name, FMODE_READ, &btrfs_fs_type, &fs_devices); break; } out: kfree(vol); return ret; } static int btrfs_freeze(struct super_block *sb) { struct btrfs_root *root = btrfs_sb(sb); mutex_lock(&root->fs_info->transaction_kthread_mutex); mutex_lock(&root->fs_info->cleaner_mutex); return 0; } static int btrfs_unfreeze(struct super_block *sb) { struct btrfs_root *root = btrfs_sb(sb); mutex_unlock(&root->fs_info->cleaner_mutex); mutex_unlock(&root->fs_info->transaction_kthread_mutex); return 0; } static struct super_operations btrfs_super_ops = { .delete_inode = btrfs_delete_inode, .put_super = btrfs_put_super, .write_super = btrfs_write_super, .sync_fs = btrfs_sync_fs, .show_options = generic_show_options, .write_inode = btrfs_write_inode, .dirty_inode = btrfs_dirty_inode, .alloc_inode = btrfs_alloc_inode, .destroy_inode = btrfs_destroy_inode, .statfs = btrfs_statfs, .remount_fs = btrfs_remount, .freeze_fs = btrfs_freeze, .unfreeze_fs = btrfs_unfreeze, }; static const struct file_operations btrfs_ctl_fops = { .unlocked_ioctl = btrfs_control_ioctl, .compat_ioctl = btrfs_control_ioctl, .owner = THIS_MODULE, }; static struct miscdevice btrfs_misc = { .minor = MISC_DYNAMIC_MINOR, .name = "btrfs-control", .fops = &btrfs_ctl_fops }; static int btrfs_interface_init(void) { return misc_register(&btrfs_misc); } static void btrfs_interface_exit(void) { if (misc_deregister(&btrfs_misc) < 0) printk(KERN_INFO "misc_deregister failed for control device"); } static int __init init_btrfs_fs(void) { int err; err = btrfs_init_sysfs(); if (err) return err; err = btrfs_init_cachep(); if (err) goto free_sysfs; err = extent_io_init(); if (err) goto free_cachep; err = extent_map_init(); if (err) goto free_extent_io; err = btrfs_interface_init(); if (err) goto free_extent_map; err = register_filesystem(&btrfs_fs_type); if (err) goto unregister_ioctl; printk(KERN_INFO "%s loaded\n", BTRFS_BUILD_VERSION); return 0; unregister_ioctl: btrfs_interface_exit(); free_extent_map: extent_map_exit(); free_extent_io: extent_io_exit(); free_cachep: btrfs_destroy_cachep(); free_sysfs: btrfs_exit_sysfs(); return err; } static void __exit exit_btrfs_fs(void) { btrfs_destroy_cachep(); extent_map_exit(); extent_io_exit(); btrfs_interface_exit(); unregister_filesystem(&btrfs_fs_type); btrfs_exit_sysfs(); btrfs_cleanup_fs_uuids(); btrfs_zlib_exit(); } module_init(init_btrfs_fs) module_exit(exit_btrfs_fs) MODULE_LICENSE("GPL");