X-Git-Url: http://ftp.safe.ca/?a=blobdiff_plain;f=fs%2Fnilfs2%2Fsuper.c;h=644e66727dd0e6f5464eb092b9d6db6caeac837f;hb=6c28705418de012216161b14a2ff1dda3da3d786;hp=6989b03e97ab57517e35abb2f56011775d4af990;hpb=e7a7402c0d392dcadc74cae8922f8fae4667605a;p=safe%2Fjmp%2Flinux-2.6 diff --git a/fs/nilfs2/super.c b/fs/nilfs2/super.c index 6989b03..644e667 100644 --- a/fs/nilfs2/super.c +++ b/fs/nilfs2/super.c @@ -50,6 +50,8 @@ #include #include #include +#include +#include #include "nilfs.h" #include "mdt.h" #include "alloc.h" @@ -66,8 +68,6 @@ MODULE_DESCRIPTION("A New Implementation of the Log-structured Filesystem " MODULE_LICENSE("GPL"); static int nilfs_remount(struct super_block *sb, int *flags, char *data); -static int test_exclusive_mount(struct file_system_type *fs_type, - struct block_device *bdev, int flags); /** * nilfs_error() - report failure condition on a filesystem @@ -134,7 +134,7 @@ void nilfs_warning(struct super_block *sb, const char *function, static struct kmem_cache *nilfs_inode_cachep; -struct inode *nilfs_alloc_inode(struct super_block *sb) +struct inode *nilfs_alloc_inode_common(struct the_nilfs *nilfs) { struct nilfs_inode_info *ii; @@ -144,10 +144,15 @@ struct inode *nilfs_alloc_inode(struct super_block *sb) ii->i_bh = NULL; ii->i_state = 0; ii->vfs_inode.i_version = 1; - nilfs_btnode_cache_init(&ii->i_btnode_cache); + nilfs_btnode_cache_init(&ii->i_btnode_cache, nilfs->ns_bdi); return &ii->vfs_inode; } +struct inode *nilfs_alloc_inode(struct super_block *sb) +{ + return nilfs_alloc_inode_common(NILFS_SB(sb)->s_nilfs); +} + void nilfs_destroy_inode(struct inode *inode) { kmem_cache_free(nilfs_inode_cachep, NILFS_I(inode)); @@ -185,16 +190,6 @@ static void nilfs_clear_inode(struct inode *inode) { struct nilfs_inode_info *ii = NILFS_I(inode); -#ifdef CONFIG_NILFS_POSIX_ACL - if (ii->i_acl && ii->i_acl != NILFS_ACL_NOT_CACHED) { - posix_acl_release(ii->i_acl); - ii->i_acl = NILFS_ACL_NOT_CACHED; - } - if (ii->i_default_acl && ii->i_default_acl != NILFS_ACL_NOT_CACHED) { - posix_acl_release(ii->i_default_acl); - ii->i_default_acl = NILFS_ACL_NOT_CACHED; - } -#endif /* * Free resources allocated in nilfs_read_inode(), here. */ @@ -315,6 +310,8 @@ static void nilfs_put_super(struct super_block *sb) struct nilfs_sb_info *sbi = NILFS_SB(sb); struct the_nilfs *nilfs = sbi->s_nilfs; + lock_kernel(); + nilfs_detach_segment_constructor(sbi); if (!(sb->s_flags & MS_RDONLY)) { @@ -323,69 +320,35 @@ static void nilfs_put_super(struct super_block *sb) nilfs_commit_super(sbi, 1); up_write(&nilfs->ns_sem); } + down_write(&nilfs->ns_super_sem); + if (nilfs->ns_current == sbi) + nilfs->ns_current = NULL; + up_write(&nilfs->ns_super_sem); nilfs_detach_checkpoint(sbi); put_nilfs(sbi->s_nilfs); sbi->s_super = NULL; sb->s_fs_info = NULL; - kfree(sbi); -} + nilfs_put_sbinfo(sbi); -/** - * nilfs_write_super - write super block(s) of NILFS - * @sb: super_block - * - * nilfs_write_super() gets a fs-dependent lock, writes super block(s), and - * clears s_dirt. This function is called in the section protected by - * lock_super(). - * - * The s_dirt flag is managed by each filesystem and we protect it by ns_sem - * of the struct the_nilfs. Lock order must be as follows: - * - * 1. lock_super() - * 2. down_write(&nilfs->ns_sem) - * - * Inside NILFS, locking ns_sem is enough to protect s_dirt and the buffer - * of the super block (nilfs->ns_sbp[]). - * - * In most cases, VFS functions call lock_super() before calling these - * methods. So we must be careful not to bring on deadlocks when using - * lock_super(); see generic_shutdown_super(), write_super(), and so on. - * - * Note that order of lock_kernel() and lock_super() depends on contexts - * of VFS. We should also note that lock_kernel() can be used in its - * protective section and only the outermost one has an effect. - */ -static void nilfs_write_super(struct super_block *sb) -{ - struct nilfs_sb_info *sbi = NILFS_SB(sb); - struct the_nilfs *nilfs = sbi->s_nilfs; - - down_write(&nilfs->ns_sem); - if (!(sb->s_flags & MS_RDONLY)) { - struct nilfs_super_block **sbp = nilfs->ns_sbp; - u64 t = get_seconds(); - int dupsb; - - if (!nilfs_discontinued(nilfs) && t >= nilfs->ns_sbwtime[0] && - t < nilfs->ns_sbwtime[0] + NILFS_SB_FREQ) { - up_write(&nilfs->ns_sem); - return; - } - dupsb = sbp[1] && t > nilfs->ns_sbwtime[1] + NILFS_ALTSB_FREQ; - nilfs_commit_super(sbi, dupsb); - } - sb->s_dirt = 0; - up_write(&nilfs->ns_sem); + unlock_kernel(); } static int nilfs_sync_fs(struct super_block *sb, int wait) { + struct nilfs_sb_info *sbi = NILFS_SB(sb); + struct the_nilfs *nilfs = sbi->s_nilfs; int err = 0; /* This function is called when super block should be written back */ if (wait) err = nilfs_construct_segment(sb); + + down_write(&nilfs->ns_sem); + if (sb->s_dirt) + nilfs_commit_super(sbi, 1); + up_write(&nilfs->ns_sem); + return err; } @@ -396,12 +359,11 @@ int nilfs_attach_checkpoint(struct nilfs_sb_info *sbi, __u64 cno) struct buffer_head *bh_cp; int err; - down_write(&nilfs->ns_sem); + down_write(&nilfs->ns_super_sem); list_add(&sbi->s_list, &nilfs->ns_supers); - up_write(&nilfs->ns_sem); + up_write(&nilfs->ns_super_sem); - sbi->s_ifile = nilfs_mdt_new( - nilfs, sbi->s_super, NILFS_IFILE_INO, NILFS_IFILE_GFP); + sbi->s_ifile = nilfs_mdt_new(nilfs, sbi->s_super, NILFS_IFILE_INO); if (!sbi->s_ifile) return -ENOMEM; @@ -409,8 +371,10 @@ int nilfs_attach_checkpoint(struct nilfs_sb_info *sbi, __u64 cno) if (unlikely(err)) goto failed; + down_read(&nilfs->ns_segctor_sem); err = nilfs_cpfile_get_checkpoint(nilfs->ns_cpfile, cno, 0, &raw_cp, &bh_cp); + up_read(&nilfs->ns_segctor_sem); if (unlikely(err)) { if (err == -ENOENT || err == -EINVAL) { printk(KERN_ERR @@ -436,9 +400,9 @@ int nilfs_attach_checkpoint(struct nilfs_sb_info *sbi, __u64 cno) nilfs_mdt_destroy(sbi->s_ifile); sbi->s_ifile = NULL; - down_write(&nilfs->ns_sem); + down_write(&nilfs->ns_super_sem); list_del_init(&sbi->s_list); - up_write(&nilfs->ns_sem); + up_write(&nilfs->ns_super_sem); return err; } @@ -450,9 +414,9 @@ void nilfs_detach_checkpoint(struct nilfs_sb_info *sbi) nilfs_mdt_clear(sbi->s_ifile); nilfs_mdt_destroy(sbi->s_ifile); sbi->s_ifile = NULL; - down_write(&nilfs->ns_sem); + down_write(&nilfs->ns_super_sem); list_del_init(&sbi->s_list); - up_write(&nilfs->ns_sem); + up_write(&nilfs->ns_super_sem); } static int nilfs_mark_recovery_complete(struct nilfs_sb_info *sbi) @@ -520,7 +484,27 @@ static int nilfs_statfs(struct dentry *dentry, struct kstatfs *buf) return 0; } -static struct super_operations nilfs_sops = { +static int nilfs_show_options(struct seq_file *seq, struct vfsmount *vfs) +{ + struct super_block *sb = vfs->mnt_sb; + struct nilfs_sb_info *sbi = NILFS_SB(sb); + + if (!nilfs_test_opt(sbi, BARRIER)) + seq_printf(seq, ",barrier=off"); + if (nilfs_test_opt(sbi, SNAPSHOT)) + seq_printf(seq, ",cp=%llu", + (unsigned long long int)sbi->s_snapshot_cno); + if (nilfs_test_opt(sbi, ERRORS_RO)) + seq_printf(seq, ",errors=remount-ro"); + if (nilfs_test_opt(sbi, ERRORS_PANIC)) + seq_printf(seq, ",errors=panic"); + if (nilfs_test_opt(sbi, STRICT_ORDER)) + seq_printf(seq, ",order=strict"); + + return 0; +} + +static const struct super_operations nilfs_sops = { .alloc_inode = nilfs_alloc_inode, .destroy_inode = nilfs_destroy_inode, .dirty_inode = nilfs_dirty_inode, @@ -529,7 +513,7 @@ static struct super_operations nilfs_sops = { /* .drop_inode = nilfs_drop_inode, */ .delete_inode = nilfs_delete_inode, .put_super = nilfs_put_super, - .write_super = nilfs_write_super, + /* .write_super = nilfs_write_super, */ .sync_fs = nilfs_sync_fs, /* .write_super_lockfs */ /* .unlockfs */ @@ -537,7 +521,7 @@ static struct super_operations nilfs_sops = { .remount_fs = nilfs_remount, .clear_inode = nilfs_clear_inode, /* .umount_begin */ - /* .show_options */ + .show_options = nilfs_show_options }; static struct inode * @@ -576,7 +560,7 @@ nilfs_fh_to_parent(struct super_block *sb, struct fid *fid, int fh_len, nilfs_nfs_get_inode); } -static struct export_operations nilfs_export_ops = { +static const struct export_operations nilfs_export_ops = { .fh_to_dentry = nilfs_fh_to_dentry, .fh_to_parent = nilfs_fh_to_parent, .get_parent = nilfs_get_parent, @@ -752,7 +736,7 @@ int nilfs_store_magic_and_option(struct super_block *sb, * @silent: silent mode flag * @nilfs: the_nilfs struct * - * This function is called exclusively by bd_mount_mutex. + * This function is called exclusively by nilfs->ns_mount_mutex. * So, the recovery process is protected from other simultaneous mounts. */ static int @@ -773,6 +757,7 @@ nilfs_fill_super(struct super_block *sb, void *data, int silent, get_nilfs(nilfs); sbi->s_nilfs = nilfs; sbi->s_super = sb; + atomic_set(&sbi->s_count, 1); err = init_nilfs(nilfs, sbi, (char *)data); if (err) @@ -806,10 +791,15 @@ nilfs_fill_super(struct super_block *sb, void *data, int silent, if (sb->s_flags & MS_RDONLY) { if (nilfs_test_opt(sbi, SNAPSHOT)) { + down_read(&nilfs->ns_segctor_sem); err = nilfs_cpfile_is_snapshot(nilfs->ns_cpfile, sbi->s_snapshot_cno); - if (err < 0) + up_read(&nilfs->ns_segctor_sem); + if (err < 0) { + if (err == -ENOENT) + err = -EINVAL; goto failed_sbi; + } if (!err) { printk(KERN_ERR "NILFS: The specified checkpoint is " @@ -870,6 +860,11 @@ nilfs_fill_super(struct super_block *sb, void *data, int silent, goto failed_root; } + down_write(&nilfs->ns_super_sem); + if (!nilfs_test_opt(sbi, SNAPSHOT)) + nilfs->ns_current = sbi; + up_write(&nilfs->ns_super_sem); + return 0; failed_root: @@ -885,7 +880,7 @@ nilfs_fill_super(struct super_block *sb, void *data, int silent, failed_sbi: put_nilfs(nilfs); sb->s_fs_info = NULL; - kfree(sbi); + nilfs_put_sbinfo(sbi); return err; } @@ -898,6 +893,9 @@ static int nilfs_remount(struct super_block *sb, int *flags, char *data) struct nilfs_mount_options old_opts; int err; + lock_kernel(); + + down_write(&nilfs->ns_super_sem); old_sb_flags = sb->s_flags; old_opts.mount_opt = sbi->s_mount_opt; old_opts.snapshot_cno = sbi->s_snapshot_cno; @@ -945,14 +943,12 @@ static int nilfs_remount(struct super_block *sb, int *flags, char *data) * store the current valid flag. (It may have been changed * by fsck since we originally mounted the partition.) */ - down(&sb->s_bdev->bd_mount_sem); - /* Check existing RW-mount */ - if (test_exclusive_mount(sb->s_type, sb->s_bdev, 0)) { + if (nilfs->ns_current && nilfs->ns_current != sbi) { printk(KERN_WARNING "NILFS (device %s): couldn't " - "remount because a RW-mount exists.\n", + "remount because an RW-mount exists.\n", sb->s_id); err = -EBUSY; - goto rw_remount_failed; + goto restore_opts; } if (sbi->s_snapshot_cno != nilfs_last_cno(nilfs)) { printk(KERN_WARNING "NILFS (device %s): couldn't " @@ -960,7 +956,7 @@ static int nilfs_remount(struct super_block *sb, int *flags, char *data) "the latest one.\n", sb->s_id); err = -EINVAL; - goto rw_remount_failed; + goto restore_opts; } sb->s_flags &= ~MS_RDONLY; nilfs_clear_opt(sbi, SNAPSHOT); @@ -968,28 +964,31 @@ static int nilfs_remount(struct super_block *sb, int *flags, char *data) err = nilfs_attach_segment_constructor(sbi); if (err) - goto rw_remount_failed; + goto restore_opts; down_write(&nilfs->ns_sem); nilfs_setup_super(sbi); up_write(&nilfs->ns_sem); - up(&sb->s_bdev->bd_mount_sem); + nilfs->ns_current = sbi; } out: + up_write(&nilfs->ns_super_sem); + unlock_kernel(); return 0; - rw_remount_failed: - up(&sb->s_bdev->bd_mount_sem); restore_opts: sb->s_flags = old_sb_flags; sbi->s_mount_opt = old_opts.mount_opt; sbi->s_snapshot_cno = old_opts.snapshot_cno; + up_write(&nilfs->ns_super_sem); + unlock_kernel(); return err; } struct nilfs_super_data { struct block_device *bdev; + struct nilfs_sb_info *sbi; __u64 cno; int flags; }; @@ -1048,33 +1047,7 @@ static int nilfs_test_bdev_super(struct super_block *s, void *data) { struct nilfs_super_data *sd = data; - return s->s_bdev == sd->bdev; -} - -static int nilfs_test_bdev_super2(struct super_block *s, void *data) -{ - struct nilfs_super_data *sd = data; - int ret; - - if (s->s_bdev != sd->bdev) - return 0; - - if (!((s->s_flags | sd->flags) & MS_RDONLY)) - return 1; /* Reuse an old R/W-mode super_block */ - - if (s->s_flags & sd->flags & MS_RDONLY) { - if (down_read_trylock(&s->s_umount)) { - ret = s->s_root && - (sd->cno == NILFS_SB(s)->s_snapshot_cno); - up_read(&s->s_umount); - /* - * This path is locked with sb_lock by sget(). - * So, drop_super() causes deadlock. - */ - return ret; - } - } - return 0; + return sd->sbi && s->s_fs_info == (void *)sd->sbi; } static int @@ -1082,8 +1055,8 @@ nilfs_get_sb(struct file_system_type *fs_type, int flags, const char *dev_name, void *data, struct vfsmount *mnt) { struct nilfs_super_data sd; - struct super_block *s, *s2; - struct the_nilfs *nilfs = NULL; + struct super_block *s; + struct the_nilfs *nilfs; int err, need_to_close = 1; sd.bdev = open_bdev_exclusive(dev_name, flags, fs_type); @@ -1095,7 +1068,6 @@ nilfs_get_sb(struct file_system_type *fs_type, int flags, * much more information than normal filesystems to identify mount * instance. For snapshot mounts, not only a mount type (ro-mount * or rw-mount) but also a checkpoint number is required. - * The results are passed in sget() using nilfs_super_data. */ sd.cno = 0; sd.flags = flags; @@ -1104,64 +1076,55 @@ nilfs_get_sb(struct file_system_type *fs_type, int flags, goto failed; } - /* - * once the super is inserted into the list by sget, s_umount - * will protect the lockfs code from trying to start a snapshot - * while we are mounting - */ - down(&sd.bdev->bd_mount_sem); - if (!sd.cno && - (err = test_exclusive_mount(fs_type, sd.bdev, flags ^ MS_RDONLY))) { - err = (err < 0) ? : -EBUSY; - goto failed_unlock; + nilfs = find_or_create_nilfs(sd.bdev); + if (!nilfs) { + err = -ENOMEM; + goto failed; } - /* - * Phase-1: search any existent instance and get the_nilfs - */ - s = sget(fs_type, nilfs_test_bdev_super, nilfs_set_bdev_super, &sd); - if (IS_ERR(s)) - goto error_s; - - if (!s->s_root) { - err = -ENOMEM; - nilfs = alloc_nilfs(sd.bdev); - if (!nilfs) - goto cancel_new; - } else { - struct nilfs_sb_info *sbi = NILFS_SB(s); + mutex_lock(&nilfs->ns_mount_mutex); + if (!sd.cno) { /* - * s_umount protects super_block from unmount process; - * It covers pointers of nilfs_sb_info and the_nilfs. + * Check if an exclusive mount exists or not. + * Snapshot mounts coexist with a current mount + * (i.e. rw-mount or ro-mount), whereas rw-mount and + * ro-mount are mutually exclusive. */ - nilfs = sbi->s_nilfs; - get_nilfs(nilfs); - up_write(&s->s_umount); + down_read(&nilfs->ns_super_sem); + if (nilfs->ns_current && + ((nilfs->ns_current->s_super->s_flags ^ flags) + & MS_RDONLY)) { + up_read(&nilfs->ns_super_sem); + err = -EBUSY; + goto failed_unlock; + } + up_read(&nilfs->ns_super_sem); + } - /* - * Phase-2: search specified snapshot or R/W mode super_block - */ - if (!sd.cno) - /* trying to get the latest checkpoint. */ - sd.cno = nilfs_last_cno(nilfs); + /* + * Find existing nilfs_sb_info struct + */ + sd.sbi = nilfs_find_sbinfo(nilfs, !(flags & MS_RDONLY), sd.cno); - s2 = sget(fs_type, nilfs_test_bdev_super2, - nilfs_set_bdev_super, &sd); - deactivate_super(s); - /* - * Although deactivate_super() invokes close_bdev_exclusive() at - * kill_block_super(). Here, s is an existent mount; we need - * one more close_bdev_exclusive() call. - */ - s = s2; - if (IS_ERR(s)) - goto error_s; + /* + * Get super block instance holding the nilfs_sb_info struct. + * A new instance is allocated if no existing mount is present or + * existing instance has been unmounted. + */ + s = sget(fs_type, nilfs_test_bdev_super, nilfs_set_bdev_super, &sd); + if (sd.sbi) + nilfs_put_sbinfo(sd.sbi); + + if (IS_ERR(s)) { + err = PTR_ERR(s); + goto failed_unlock; } if (!s->s_root) { char b[BDEVNAME_SIZE]; + /* New superblock instance created */ s->s_flags = flags; strlcpy(s->s_id, bdevname(sd.bdev, b), sizeof(s->s_id)); sb_set_blocksize(s, block_size(sd.bdev)); @@ -1172,26 +1135,18 @@ nilfs_get_sb(struct file_system_type *fs_type, int flags, s->s_flags |= MS_ACTIVE; need_to_close = 0; - } else if (!(s->s_flags & MS_RDONLY)) { - err = -EBUSY; } - up(&sd.bdev->bd_mount_sem); + mutex_unlock(&nilfs->ns_mount_mutex); put_nilfs(nilfs); if (need_to_close) close_bdev_exclusive(sd.bdev, flags); simple_set_mnt(mnt, s); return 0; - error_s: - up(&sd.bdev->bd_mount_sem); - if (nilfs) - put_nilfs(nilfs); - close_bdev_exclusive(sd.bdev, flags); - return PTR_ERR(s); - failed_unlock: - up(&sd.bdev->bd_mount_sem); + mutex_unlock(&nilfs->ns_mount_mutex); + put_nilfs(nilfs); failed: close_bdev_exclusive(sd.bdev, flags); @@ -1199,70 +1154,18 @@ nilfs_get_sb(struct file_system_type *fs_type, int flags, cancel_new: /* Abandoning the newly allocated superblock */ - up(&sd.bdev->bd_mount_sem); - if (nilfs) - put_nilfs(nilfs); + mutex_unlock(&nilfs->ns_mount_mutex); + put_nilfs(nilfs); up_write(&s->s_umount); deactivate_super(s); /* * deactivate_super() invokes close_bdev_exclusive(). * We must finish all post-cleaning before this call; - * put_nilfs() and unlocking bd_mount_sem need the block device. + * put_nilfs() needs the block device. */ return err; } -static int nilfs_test_bdev_super3(struct super_block *s, void *data) -{ - struct nilfs_super_data *sd = data; - int ret; - - if (s->s_bdev != sd->bdev) - return 0; - if (down_read_trylock(&s->s_umount)) { - ret = (s->s_flags & MS_RDONLY) && s->s_root && - nilfs_test_opt(NILFS_SB(s), SNAPSHOT); - up_read(&s->s_umount); - if (ret) - return 0; /* ignore snapshot mounts */ - } - return !((sd->flags ^ s->s_flags) & MS_RDONLY); -} - -static int __false_bdev_super(struct super_block *s, void *data) -{ -#if 0 /* XXX: workaround for lock debug. This is not good idea */ - up_write(&s->s_umount); -#endif - return -EFAULT; -} - -/** - * test_exclusive_mount - check whether an exclusive RW/RO mount exists or not. - * fs_type: filesystem type - * bdev: block device - * flag: 0 (check rw-mount) or MS_RDONLY (check ro-mount) - * res: pointer to an integer to store result - * - * This function must be called within a section protected by bd_mount_mutex. - */ -static int test_exclusive_mount(struct file_system_type *fs_type, - struct block_device *bdev, int flags) -{ - struct super_block *s; - struct nilfs_super_data sd = { .flags = flags, .bdev = bdev }; - - s = sget(fs_type, nilfs_test_bdev_super3, __false_bdev_super, &sd); - if (IS_ERR(s)) { - if (PTR_ERR(s) != -EFAULT) - return PTR_ERR(s); - return 0; /* Not found */ - } - up_write(&s->s_umount); - deactivate_super(s); - return 1; /* Found */ -} - struct file_system_type nilfs_fs_type = { .owner = THIS_MODULE, .name = "nilfs2",