From a0af469b58944f6e8c5c8ecbebb42997baf0cb9e Mon Sep 17 00:00:00 2001 From: Chris Mason Date: Tue, 13 May 2008 16:03:06 -0400 Subject: [PATCH] Fix btrfs_open_devices to deal with changes since the scan ioctls Devices can change after the scan ioctls are done, and btrfs_open_devices needs to be able to verify them as they are opened and used by the FS. Signed-off-by: Chris Mason --- fs/btrfs/disk-io.c | 4 +-- fs/btrfs/volumes.c | 70 ++++++++++++++++++++++++++++++++++++++-------- fs/btrfs/volumes.h | 4 +-- 3 files changed, 63 insertions(+), 15 deletions(-) diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c index 38b0d9ecda6a..264f297260f8 100644 --- a/fs/btrfs/disk-io.c +++ b/fs/btrfs/disk-io.c @@ -1266,10 +1266,10 @@ struct btrfs_root *open_ctree(struct super_block *sb, btrfs_parse_options(options, tree_root, NULL); - if (btrfs_super_num_devices(disk_super) > fs_devices->num_devices) { + if (btrfs_super_num_devices(disk_super) > fs_devices->open_devices) { printk("Btrfs: wanted %llu devices, but found %llu\n", (unsigned long long)btrfs_super_num_devices(disk_super), - (unsigned long long)fs_devices->num_devices); + (unsigned long long)fs_devices->open_devices); if (btrfs_test_opt(tree_root, DEGRADED)) printk("continuing in degraded mode\n"); else { diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c index 43f74d17bcea..501d23d3ebfd 100644 --- a/fs/btrfs/volumes.c +++ b/fs/btrfs/volumes.c @@ -71,6 +71,7 @@ int btrfs_cleanup_fs_uuids(void) dev_list); if (dev->bdev) { close_bdev_excl(dev->bdev); + fs_devices->open_devices--; } list_del(&dev->dev_list); kfree(dev->name); @@ -174,9 +175,10 @@ again: list_for_each(cur, head) { device = list_entry(cur, struct btrfs_device, dev_list); if (!device->in_fs_metadata) { -printk("getting rid of extra dev %s\n", device->name); - if (device->bdev) + if (device->bdev) { close_bdev_excl(device->bdev); + fs_devices->open_devices--; + } list_del(&device->dev_list); list_del(&device->dev_alloc_list); fs_devices->num_devices--; @@ -188,6 +190,7 @@ printk("getting rid of extra dev %s\n", device->name); mutex_unlock(&uuid_mutex); return 0; } + int btrfs_close_devices(struct btrfs_fs_devices *fs_devices) { struct list_head *head = &fs_devices->devices; @@ -199,10 +202,12 @@ int btrfs_close_devices(struct btrfs_fs_devices *fs_devices) device = list_entry(cur, struct btrfs_device, dev_list); if (device->bdev) { close_bdev_excl(device->bdev); + fs_devices->open_devices--; } device->bdev = NULL; device->in_fs_metadata = 0; } + fs_devices->mounted = 0; mutex_unlock(&uuid_mutex); return 0; } @@ -214,9 +219,19 @@ int btrfs_open_devices(struct btrfs_fs_devices *fs_devices, struct list_head *head = &fs_devices->devices; struct list_head *cur; struct btrfs_device *device; - int ret; + struct block_device *latest_bdev = NULL; + struct buffer_head *bh; + struct btrfs_super_block *disk_super; + u64 latest_devid = 0; + u64 latest_transid = 0; + u64 transid; + u64 devid; + int ret = 0; mutex_lock(&uuid_mutex); + if (fs_devices->mounted) + goto out; + list_for_each(cur, head) { device = list_entry(cur, struct btrfs_device, dev_list); if (device->bdev) @@ -229,21 +244,52 @@ int btrfs_open_devices(struct btrfs_fs_devices *fs_devices, if (IS_ERR(bdev)) { printk("open %s failed\n", device->name); - ret = PTR_ERR(bdev); - goto fail; + goto error; } set_blocksize(bdev, 4096); - if (device->devid == fs_devices->latest_devid) - fs_devices->latest_bdev = bdev; + + bh = __bread(bdev, BTRFS_SUPER_INFO_OFFSET / 4096, 4096); + if (!bh) + goto error_close; + + disk_super = (struct btrfs_super_block *)bh->b_data; + if (strncmp((char *)(&disk_super->magic), BTRFS_MAGIC, + sizeof(disk_super->magic))) + goto error_brelse; + + devid = le64_to_cpu(disk_super->dev_item.devid); + if (devid != device->devid) + goto error_brelse; + + transid = btrfs_super_generation(disk_super); + if (transid > latest_transid) { + latest_devid = devid; + latest_transid = transid; + latest_bdev = bdev; + } + device->bdev = bdev; device->in_fs_metadata = 0; + fs_devices->open_devices++; + continue; +error_brelse: + brelse(bh); +error_close: + close_bdev_excl(bdev); +error: + continue; } + if (fs_devices->open_devices == 0) { + ret = -EIO; + goto out; + } + fs_devices->mounted = 1; + fs_devices->latest_bdev = latest_bdev; + fs_devices->latest_devid = latest_devid; + fs_devices->latest_trans = latest_transid; +out: mutex_unlock(&uuid_mutex); - return 0; -fail: - mutex_unlock(&uuid_mutex); - btrfs_close_devices(fs_devices); return ret; } @@ -828,6 +874,7 @@ int btrfs_rm_device(struct btrfs_root *root, char *device_path) if (device->bdev) { /* one close for the device struct or super_block */ close_bdev_excl(device->bdev); + root->fs_info->fs_devices->open_devices--; } if (bdev) { /* one close for us */ @@ -914,6 +961,7 @@ int btrfs_init_new_device(struct btrfs_root *root, char *device_path) list_add(&device->dev_alloc_list, &root->fs_info->fs_devices->alloc_list); root->fs_info->fs_devices->num_devices++; + root->fs_info->fs_devices->open_devices++; out: btrfs_end_transaction(trans, root); mutex_unlock(&root->fs_info->fs_mutex); diff --git a/fs/btrfs/volumes.h b/fs/btrfs/volumes.h index 454fe8103329..4df6b1608f91 100644 --- a/fs/btrfs/volumes.h +++ b/fs/btrfs/volumes.h @@ -71,16 +71,16 @@ struct btrfs_fs_devices { /* the device with this id has the most recent coyp of the super */ u64 latest_devid; u64 latest_trans; - u64 lowest_devid; u64 num_devices; + u64 open_devices; struct block_device *latest_bdev; - struct block_device *lowest_bdev; /* all of the devices in the FS */ struct list_head devices; /* devices not currently being allocated */ struct list_head alloc_list; struct list_head list; + int mounted; }; struct btrfs_bio_stripe { -- 2.34.1