From 6cf86a006be9f2a77434d5a06ea289719815ad7c Mon Sep 17 00:00:00 2001
From: Anand Jain <anand.jain@oracle.com>
Date: Sat, 13 Feb 2016 10:01:29 +0800
Subject: btrfs: create a helper function to read the disk super

A part of code from btrfs_scan_one_device() is moved to a new function
btrfs_read_disk_super(), so that former function looks cleaner. (In this
process it also moves the code which ensures null terminating label). So
this creates easy opportunity to merge various duplicate codes on read
disk super. Earlier attempt to merge duplicate codes highlighted that
there were some issues for which there are duplicate codes (to read disk
super), however it was not clear what was the issue. So until we figure
that out, its better to keep them in a separate functions.

Signed-off-by: Anand Jain <anand.jain@oracle.com>
[ use GFP_KERNEL, PAGE_CACHE_ removal related fixups ]
Signed-off-by: David Sterba <dsterba@suse.com>
---
 fs/btrfs/volumes.c | 87 ++++++++++++++++++++++++++++++++----------------------
 1 file changed, 52 insertions(+), 35 deletions(-)

(limited to 'fs')

diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index bd0f45fb38c4..5006683283ae 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -988,6 +988,56 @@ int btrfs_open_devices(struct btrfs_fs_devices *fs_devices,
 	return ret;
 }
 
+void btrfs_release_disk_super(struct page *page)
+{
+	kunmap(page);
+	put_page(page);
+}
+
+int btrfs_read_disk_super(struct block_device *bdev, u64 bytenr,
+		struct page **page, struct btrfs_super_block **disk_super)
+{
+	void *p;
+	pgoff_t index;
+
+	/* make sure our super fits in the device */
+	if (bytenr + PAGE_SIZE >= i_size_read(bdev->bd_inode))
+		return 1;
+
+	/* make sure our super fits in the page */
+	if (sizeof(**disk_super) > PAGE_SIZE)
+		return 1;
+
+	/* make sure our super doesn't straddle pages on disk */
+	index = bytenr >> PAGE_SHIFT;
+	if ((bytenr + sizeof(**disk_super) - 1) >> PAGE_SHIFT != index)
+		return 1;
+
+	/* pull in the page with our super */
+	*page = read_cache_page_gfp(bdev->bd_inode->i_mapping,
+				   index, GFP_KERNEL);
+
+	if (IS_ERR_OR_NULL(*page))
+		return 1;
+
+	p = kmap(*page);
+
+	/* align our pointer to the offset of the super block */
+	*disk_super = p + (bytenr & ~PAGE_MASK);
+
+	if (btrfs_super_bytenr(*disk_super) != bytenr ||
+	    btrfs_super_magic(*disk_super) != BTRFS_MAGIC) {
+		btrfs_release_disk_super(*page);
+		return 1;
+	}
+
+	if ((*disk_super)->label[0] &&
+		(*disk_super)->label[BTRFS_LABEL_SIZE - 1])
+		(*disk_super)->label[BTRFS_LABEL_SIZE - 1] = '\0';
+
+	return 0;
+}
+
 /*
  * Look for a btrfs signature on a device. This may be called out of the mount path
  * and we are not allowed to call set_blocksize during the scan. The superblock
@@ -999,13 +1049,11 @@ int btrfs_scan_one_device(const char *path, fmode_t flags, void *holder,
 	struct btrfs_super_block *disk_super;
 	struct block_device *bdev;
 	struct page *page;
-	void *p;
 	int ret = -EINVAL;
 	u64 devid;
 	u64 transid;
 	u64 total_devices;
 	u64 bytenr;
-	pgoff_t index;
 
 	/*
 	 * we would like to check all the supers, but that would make
@@ -1018,41 +1066,14 @@ int btrfs_scan_one_device(const char *path, fmode_t flags, void *holder,
 	mutex_lock(&uuid_mutex);
 
 	bdev = blkdev_get_by_path(path, flags, holder);
-
 	if (IS_ERR(bdev)) {
 		ret = PTR_ERR(bdev);
 		goto error;
 	}
 
-	/* make sure our super fits in the device */
-	if (bytenr + PAGE_SIZE >= i_size_read(bdev->bd_inode))
-		goto error_bdev_put;
-
-	/* make sure our super fits in the page */
-	if (sizeof(*disk_super) > PAGE_SIZE)
-		goto error_bdev_put;
-
-	/* make sure our super doesn't straddle pages on disk */
-	index = bytenr >> PAGE_SHIFT;
-	if ((bytenr + sizeof(*disk_super) - 1) >> PAGE_SHIFT != index)
-		goto error_bdev_put;
-
-	/* pull in the page with our super */
-	page = read_cache_page_gfp(bdev->bd_inode->i_mapping,
-				   index, GFP_NOFS);
-
-	if (IS_ERR_OR_NULL(page))
+	if (btrfs_read_disk_super(bdev, bytenr, &page, &disk_super))
 		goto error_bdev_put;
 
-	p = kmap(page);
-
-	/* align our pointer to the offset of the super block */
-	disk_super = p + (bytenr & ~PAGE_MASK);
-
-	if (btrfs_super_bytenr(disk_super) != bytenr ||
-	    btrfs_super_magic(disk_super) != BTRFS_MAGIC)
-		goto error_unmap;
-
 	devid = btrfs_stack_device_id(&disk_super->dev_item);
 	transid = btrfs_super_generation(disk_super);
 	total_devices = btrfs_super_num_devices(disk_super);
@@ -1060,8 +1081,6 @@ int btrfs_scan_one_device(const char *path, fmode_t flags, void *holder,
 	ret = device_list_add(path, disk_super, devid, fs_devices_ret);
 	if (ret > 0) {
 		if (disk_super->label[0]) {
-			if (disk_super->label[BTRFS_LABEL_SIZE - 1])
-				disk_super->label[BTRFS_LABEL_SIZE - 1] = '\0';
 			printk(KERN_INFO "BTRFS: device label %s ", disk_super->label);
 		} else {
 			printk(KERN_INFO "BTRFS: device fsid %pU ", disk_super->fsid);
@@ -1073,9 +1092,7 @@ int btrfs_scan_one_device(const char *path, fmode_t flags, void *holder,
 	if (!ret && fs_devices_ret)
 		(*fs_devices_ret)->total_devices = total_devices;
 
-error_unmap:
-	kunmap(page);
-	put_page(page);
+	btrfs_release_disk_super(page);
 
 error_bdev_put:
 	blkdev_put(bdev, flags);
-- 
cgit v1.2.3


From f1fa7f264250f2cb60119aca3fd114c3f47070c2 Mon Sep 17 00:00:00 2001
From: Anand Jain <anand.jain@oracle.com>
Date: Sat, 13 Feb 2016 10:01:33 +0800
Subject: btrfs: create helper function __check_raid_min_devices()

move a section of btrfs_rm_device() code to check for min number of the
devices into the function __check_raid_min_devices()

Signed-off-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
---
 fs/btrfs/volumes.c | 51 ++++++++++++++++++++++++++++++++-------------------
 1 file changed, 32 insertions(+), 19 deletions(-)

(limited to 'fs')

diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index 5006683283ae..db781d0d3678 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -1705,23 +1705,20 @@ out:
 	return ret;
 }
 
-int btrfs_rm_device(struct btrfs_root *root, char *device_path)
+static int __check_raid_min_devices(struct btrfs_root *root)
 {
-	struct btrfs_device *device;
-	struct btrfs_device *next_device;
-	struct block_device *bdev;
-	struct buffer_head *bh = NULL;
-	struct btrfs_super_block *disk_super;
-	struct btrfs_fs_devices *cur_devices;
 	u64 all_avail;
-	u64 devid;
 	u64 num_devices;
-	u8 *dev_uuid;
 	unsigned seq;
 	int ret = 0;
-	bool clear_super = false;
 
-	mutex_lock(&uuid_mutex);
+	num_devices = root->fs_info->fs_devices->num_devices;
+	btrfs_dev_replace_lock(&root->fs_info->dev_replace, 0);
+	if (btrfs_dev_replace_is_ongoing(&root->fs_info->dev_replace)) {
+		WARN_ON(num_devices < 1);
+		num_devices--;
+	}
+	btrfs_dev_replace_unlock(&root->fs_info->dev_replace, 0);
 
 	do {
 		seq = read_seqbegin(&root->fs_info->profiles_lock);
@@ -1731,14 +1728,6 @@ int btrfs_rm_device(struct btrfs_root *root, char *device_path)
 			    root->fs_info->avail_metadata_alloc_bits;
 	} while (read_seqretry(&root->fs_info->profiles_lock, seq));
 
-	num_devices = root->fs_info->fs_devices->num_devices;
-	btrfs_dev_replace_lock(&root->fs_info->dev_replace, 0);
-	if (btrfs_dev_replace_is_ongoing(&root->fs_info->dev_replace)) {
-		WARN_ON(num_devices < 1);
-		num_devices--;
-	}
-	btrfs_dev_replace_unlock(&root->fs_info->dev_replace, 0);
-
 	if ((all_avail & BTRFS_BLOCK_GROUP_RAID10) && num_devices <= 4) {
 		ret = BTRFS_ERROR_DEV_RAID10_MIN_NOT_MET;
 		goto out;
@@ -1760,6 +1749,30 @@ int btrfs_rm_device(struct btrfs_root *root, char *device_path)
 		goto out;
 	}
 
+out:
+	return ret;
+}
+
+int btrfs_rm_device(struct btrfs_root *root, char *device_path)
+{
+	struct btrfs_device *device;
+	struct btrfs_device *next_device;
+	struct block_device *bdev;
+	struct buffer_head *bh = NULL;
+	struct btrfs_super_block *disk_super;
+	struct btrfs_fs_devices *cur_devices;
+	u64 devid;
+	u64 num_devices;
+	u8 *dev_uuid;
+	int ret = 0;
+	bool clear_super = false;
+
+	mutex_lock(&uuid_mutex);
+
+	ret = __check_raid_min_devices(root);
+	if (ret)
+		goto out;
+
 	if (strcmp(device_path, "missing") == 0) {
 		struct list_head *devices;
 		struct btrfs_device *tmp;
-- 
cgit v1.2.3


From bd45ffbcb1f082e3c5a0bd56b1d7310d8b707ffb Mon Sep 17 00:00:00 2001
From: Anand Jain <anand.jain@oracle.com>
Date: Sat, 13 Feb 2016 10:01:34 +0800
Subject: btrfs: clean up and optimize __check_raid_min_device()

__check_raid_min_device() which was pealed from btrfs_rm_device()
maintianed its original code to show the block move. This patch cleans up
__check_raid_min_device().

Signed-off-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
---
 fs/btrfs/volumes.c | 43 +++++++++++++++++++------------------------
 1 file changed, 19 insertions(+), 24 deletions(-)

(limited to 'fs')

diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index db781d0d3678..5538dc78c72e 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -1705,52 +1705,47 @@ out:
 	return ret;
 }
 
-static int __check_raid_min_devices(struct btrfs_root *root)
+static int __check_raid_min_devices(struct btrfs_fs_info *fs_info)
 {
 	u64 all_avail;
 	u64 num_devices;
 	unsigned seq;
-	int ret = 0;
 
-	num_devices = root->fs_info->fs_devices->num_devices;
-	btrfs_dev_replace_lock(&root->fs_info->dev_replace, 0);
-	if (btrfs_dev_replace_is_ongoing(&root->fs_info->dev_replace)) {
+	num_devices = fs_info->fs_devices->num_devices;
+	btrfs_dev_replace_lock(&fs_info->dev_replace, 0);
+	if (btrfs_dev_replace_is_ongoing(&fs_info->dev_replace)) {
 		WARN_ON(num_devices < 1);
 		num_devices--;
 	}
-	btrfs_dev_replace_unlock(&root->fs_info->dev_replace, 0);
+	btrfs_dev_replace_unlock(&fs_info->dev_replace, 0);
 
 	do {
-		seq = read_seqbegin(&root->fs_info->profiles_lock);
+		seq = read_seqbegin(&fs_info->profiles_lock);
 
-		all_avail = root->fs_info->avail_data_alloc_bits |
-			    root->fs_info->avail_system_alloc_bits |
-			    root->fs_info->avail_metadata_alloc_bits;
-	} while (read_seqretry(&root->fs_info->profiles_lock, seq));
+		all_avail = fs_info->avail_data_alloc_bits |
+			    fs_info->avail_system_alloc_bits |
+			    fs_info->avail_metadata_alloc_bits;
+	} while (read_seqretry(&fs_info->profiles_lock, seq));
 
 	if ((all_avail & BTRFS_BLOCK_GROUP_RAID10) && num_devices <= 4) {
-		ret = BTRFS_ERROR_DEV_RAID10_MIN_NOT_MET;
-		goto out;
+		return BTRFS_ERROR_DEV_RAID10_MIN_NOT_MET;
 	}
 
 	if ((all_avail & BTRFS_BLOCK_GROUP_RAID1) && num_devices <= 2) {
-		ret = BTRFS_ERROR_DEV_RAID1_MIN_NOT_MET;
-		goto out;
+		return BTRFS_ERROR_DEV_RAID1_MIN_NOT_MET;
 	}
 
 	if ((all_avail & BTRFS_BLOCK_GROUP_RAID5) &&
-	    root->fs_info->fs_devices->rw_devices <= 2) {
-		ret = BTRFS_ERROR_DEV_RAID5_MIN_NOT_MET;
-		goto out;
+	    fs_info->fs_devices->rw_devices <= 2) {
+		return BTRFS_ERROR_DEV_RAID5_MIN_NOT_MET;
 	}
+
 	if ((all_avail & BTRFS_BLOCK_GROUP_RAID6) &&
-	    root->fs_info->fs_devices->rw_devices <= 3) {
-		ret = BTRFS_ERROR_DEV_RAID6_MIN_NOT_MET;
-		goto out;
+	    fs_info->fs_devices->rw_devices <= 3) {
+		return BTRFS_ERROR_DEV_RAID6_MIN_NOT_MET;
 	}
 
-out:
-	return ret;
+	return 0;
 }
 
 int btrfs_rm_device(struct btrfs_root *root, char *device_path)
@@ -1769,7 +1764,7 @@ int btrfs_rm_device(struct btrfs_root *root, char *device_path)
 
 	mutex_lock(&uuid_mutex);
 
-	ret = __check_raid_min_devices(root);
+	ret = __check_raid_min_devices(root->fs_info);
 	if (ret)
 		goto out;
 
-- 
cgit v1.2.3


From 24e0474b59538cdb9d2b7318ec7c7ae9f6faf85d Mon Sep 17 00:00:00 2001
From: Anand Jain <anand.jain@oracle.com>
Date: Sat, 13 Feb 2016 10:01:35 +0800
Subject: btrfs: create helper btrfs_find_device_by_user_input()

The patch renames btrfs_dev_replace_find_srcdev() to
btrfs_find_device_by_user_input() and moves it to volumes.c, so that
delete device can use it.

Signed-off-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
---
 fs/btrfs/dev-replace.c | 24 +-----------------------
 fs/btrfs/volumes.c     | 19 +++++++++++++++++++
 fs/btrfs/volumes.h     |  3 +++
 3 files changed, 23 insertions(+), 23 deletions(-)

(limited to 'fs')

diff --git a/fs/btrfs/dev-replace.c b/fs/btrfs/dev-replace.c
index 26bcb487f958..7ad8ae994ca0 100644
--- a/fs/btrfs/dev-replace.c
+++ b/fs/btrfs/dev-replace.c
@@ -44,9 +44,6 @@ static void btrfs_dev_replace_update_device_in_mapping_tree(
 						struct btrfs_fs_info *fs_info,
 						struct btrfs_device *srcdev,
 						struct btrfs_device *tgtdev);
-static int btrfs_dev_replace_find_srcdev(struct btrfs_root *root, u64 srcdevid,
-					 char *srcdev_name,
-					 struct btrfs_device **device);
 static u64 __btrfs_dev_replace_cancel(struct btrfs_fs_info *fs_info);
 static int btrfs_dev_replace_kthread(void *data);
 static int btrfs_dev_replace_continue_on_mount(struct btrfs_fs_info *fs_info);
@@ -329,7 +326,7 @@ int btrfs_dev_replace_start(struct btrfs_root *root,
 
 	/* the disk copy procedure reuses the scrub code */
 	mutex_lock(&fs_info->volume_mutex);
-	ret = btrfs_dev_replace_find_srcdev(root, args->start.srcdevid,
+	ret = btrfs_find_device_by_user_input(root, args->start.srcdevid,
 					    args->start.srcdev_name,
 					    &src_device);
 	if (ret) {
@@ -626,25 +623,6 @@ static void btrfs_dev_replace_update_device_in_mapping_tree(
 	write_unlock(&em_tree->lock);
 }
 
-static int btrfs_dev_replace_find_srcdev(struct btrfs_root *root, u64 srcdevid,
-					 char *srcdev_name,
-					 struct btrfs_device **device)
-{
-	int ret;
-
-	if (srcdevid) {
-		ret = 0;
-		*device = btrfs_find_device(root->fs_info, srcdevid, NULL,
-					    NULL);
-		if (!*device)
-			ret = -ENOENT;
-	} else {
-		ret = btrfs_find_device_missing_or_by_path(root, srcdev_name,
-							   device);
-	}
-	return ret;
-}
-
 void btrfs_dev_replace_status(struct btrfs_fs_info *fs_info,
 			      struct btrfs_ioctl_dev_replace_args *args)
 {
diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index 5538dc78c72e..ab28d9dc1b0d 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -2126,6 +2126,25 @@ int btrfs_find_device_missing_or_by_path(struct btrfs_root *root,
 	}
 }
 
+int btrfs_find_device_by_user_input(struct btrfs_root *root, u64 srcdevid,
+					 char *srcdev_name,
+					 struct btrfs_device **device)
+{
+	int ret;
+
+	if (srcdevid) {
+		ret = 0;
+		*device = btrfs_find_device(root->fs_info, srcdevid, NULL,
+					    NULL);
+		if (!*device)
+			ret = -ENOENT;
+	} else {
+		ret = btrfs_find_device_missing_or_by_path(root, srcdev_name,
+							   device);
+	}
+	return ret;
+}
+
 /*
  * does all the dirty work required for changing file system's UUID.
  */
diff --git a/fs/btrfs/volumes.h b/fs/btrfs/volumes.h
index 1939ebde63df..508739314e43 100644
--- a/fs/btrfs/volumes.h
+++ b/fs/btrfs/volumes.h
@@ -448,6 +448,9 @@ void btrfs_close_extra_devices(struct btrfs_fs_devices *fs_devices, int step);
 int btrfs_find_device_missing_or_by_path(struct btrfs_root *root,
 					 char *device_path,
 					 struct btrfs_device **device);
+int btrfs_find_device_by_user_input(struct btrfs_root *root, u64 srcdevid,
+					 char *srcdev_name,
+					 struct btrfs_device **device);
 struct btrfs_device *btrfs_alloc_device(struct btrfs_fs_info *fs_info,
 					const u64 *devid,
 					const u8 *uuid);
-- 
cgit v1.2.3


From 24fc572fe456c02ff4136c07861a3edd4b8de683 Mon Sep 17 00:00:00 2001
From: Anand Jain <anand.jain@oracle.com>
Date: Sat, 13 Feb 2016 10:01:36 +0800
Subject: btrfs: make use of btrfs_find_device_by_user_input()

btrfs_rm_device() has a section of the code which can be replaced
btrfs_find_device_by_user_input()

Signed-off-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
---
 fs/btrfs/volumes.c | 100 ++++++++++++++++++++---------------------------------
 1 file changed, 37 insertions(+), 63 deletions(-)

(limited to 'fs')

diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index ab28d9dc1b0d..40bbe0a2715b 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -1752,13 +1752,11 @@ int btrfs_rm_device(struct btrfs_root *root, char *device_path)
 {
 	struct btrfs_device *device;
 	struct btrfs_device *next_device;
-	struct block_device *bdev;
+	struct block_device *bdev = NULL;
 	struct buffer_head *bh = NULL;
-	struct btrfs_super_block *disk_super;
+	struct btrfs_super_block *disk_super = NULL;
 	struct btrfs_fs_devices *cur_devices;
-	u64 devid;
 	u64 num_devices;
-	u8 *dev_uuid;
 	int ret = 0;
 	bool clear_super = false;
 
@@ -1768,57 +1766,19 @@ int btrfs_rm_device(struct btrfs_root *root, char *device_path)
 	if (ret)
 		goto out;
 
-	if (strcmp(device_path, "missing") == 0) {
-		struct list_head *devices;
-		struct btrfs_device *tmp;
-
-		device = NULL;
-		devices = &root->fs_info->fs_devices->devices;
-		/*
-		 * It is safe to read the devices since the volume_mutex
-		 * is held.
-		 */
-		list_for_each_entry(tmp, devices, dev_list) {
-			if (tmp->in_fs_metadata &&
-			    !tmp->is_tgtdev_for_dev_replace &&
-			    !tmp->bdev) {
-				device = tmp;
-				break;
-			}
-		}
-		bdev = NULL;
-		bh = NULL;
-		disk_super = NULL;
-		if (!device) {
-			ret = BTRFS_ERROR_DEV_MISSING_NOT_FOUND;
-			goto out;
-		}
-	} else {
-		ret = btrfs_get_bdev_and_sb(device_path,
-					    FMODE_WRITE | FMODE_EXCL,
-					    root->fs_info->bdev_holder, 0,
-					    &bdev, &bh);
-		if (ret)
-			goto out;
-		disk_super = (struct btrfs_super_block *)bh->b_data;
-		devid = btrfs_stack_device_id(&disk_super->dev_item);
-		dev_uuid = disk_super->dev_item.uuid;
-		device = btrfs_find_device(root->fs_info, devid, dev_uuid,
-					   disk_super->fsid);
-		if (!device) {
-			ret = -ENOENT;
-			goto error_brelse;
-		}
-	}
+	ret = btrfs_find_device_by_user_input(root, 0, device_path,
+				&device);
+	if (ret)
+		goto out;
 
 	if (device->is_tgtdev_for_dev_replace) {
 		ret = BTRFS_ERROR_DEV_TGT_REPLACE;
-		goto error_brelse;
+		goto out;
 	}
 
 	if (device->writeable && root->fs_info->fs_devices->rw_devices == 1) {
 		ret = BTRFS_ERROR_DEV_ONLY_WRITABLE;
-		goto error_brelse;
+		goto out;
 	}
 
 	if (device->writeable) {
@@ -1908,16 +1868,33 @@ int btrfs_rm_device(struct btrfs_root *root, char *device_path)
 	 * at this point, the device is zero sized.  We want to
 	 * remove it from the devices list and zero out the old super
 	 */
-	if (clear_super && disk_super) {
+	if (clear_super) {
 		u64 bytenr;
 		int i;
 
+		if (!disk_super) {
+			ret = btrfs_get_bdev_and_sb(device_path,
+					FMODE_WRITE | FMODE_EXCL,
+					root->fs_info->bdev_holder, 0,
+					&bdev, &bh);
+			if (ret) {
+				/*
+				 * It could be a failed device ok for clear_super
+				 * to fail. So return success
+				 */
+				ret = 0;
+				goto out;
+			}
+
+			disk_super = (struct btrfs_super_block *)bh->b_data;
+		}
 		/* make sure this device isn't detected as part of
 		 * the FS anymore
 		 */
 		memset(&disk_super->magic, 0, sizeof(disk_super->magic));
 		set_buffer_dirty(bh);
 		sync_dirty_buffer(bh);
+		brelse(bh);
 
 		/* clear the mirror copies of super block on the disk
 		 * being removed, 0th copy is been taken care above and
@@ -1929,7 +1906,6 @@ int btrfs_rm_device(struct btrfs_root *root, char *device_path)
 					i_size_read(bdev->bd_inode))
 				break;
 
-			brelse(bh);
 			bh = __bread(bdev, bytenr / 4096,
 					BTRFS_SUPER_INFO_SIZE);
 			if (!bh)
@@ -1939,32 +1915,30 @@ int btrfs_rm_device(struct btrfs_root *root, char *device_path)
 
 			if (btrfs_super_bytenr(disk_super) != bytenr ||
 				btrfs_super_magic(disk_super) != BTRFS_MAGIC) {
+				brelse(bh);
 				continue;
 			}
 			memset(&disk_super->magic, 0,
 						sizeof(disk_super->magic));
 			set_buffer_dirty(bh);
 			sync_dirty_buffer(bh);
+			brelse(bh);
 		}
-	}
 
-	ret = 0;
-
-	if (bdev) {
-		/* Notify udev that device has changed */
-		btrfs_kobject_uevent(bdev, KOBJ_CHANGE);
+		if (bdev) {
+			/* Notify udev that device has changed */
+			btrfs_kobject_uevent(bdev, KOBJ_CHANGE);
 
-		/* Update ctime/mtime for device path for libblkid */
-		update_dev_time(device_path);
+			/* Update ctime/mtime for device path for libblkid */
+			update_dev_time(device_path);
+			blkdev_put(bdev, FMODE_READ | FMODE_EXCL);
+		}
 	}
 
-error_brelse:
-	brelse(bh);
-	if (bdev)
-		blkdev_put(bdev, FMODE_READ | FMODE_EXCL);
 out:
 	mutex_unlock(&uuid_mutex);
 	return ret;
+
 error_undo:
 	if (device->writeable) {
 		lock_chunks(root);
@@ -1973,7 +1947,7 @@ error_undo:
 		device->fs_devices->rw_devices++;
 		unlock_chunks(root);
 	}
-	goto error_brelse;
+	goto out;
 }
 
 void btrfs_rm_dev_replace_remove_srcdev(struct btrfs_fs_info *fs_info,
-- 
cgit v1.2.3


From b3d1b1532ff9620ff5dba891a96f3e912005eb10 Mon Sep 17 00:00:00 2001
From: Anand Jain <anand.jain@oracle.com>
Date: Sat, 13 Feb 2016 10:01:37 +0800
Subject: btrfs: enhance btrfs_find_device_by_user_input() to check device path

The operation of device replace and device delete follows same steps upto
some depth with in btrfs kernel, however they don't share codes. This
enhancement will help replace and delete to share codes.

Signed-off-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
---
 fs/btrfs/dev-replace.c | 4 ----
 fs/btrfs/volumes.c     | 3 +++
 2 files changed, 3 insertions(+), 4 deletions(-)

(limited to 'fs')

diff --git a/fs/btrfs/dev-replace.c b/fs/btrfs/dev-replace.c
index 7ad8ae994ca0..fdd2880707df 100644
--- a/fs/btrfs/dev-replace.c
+++ b/fs/btrfs/dev-replace.c
@@ -320,10 +320,6 @@ int btrfs_dev_replace_start(struct btrfs_root *root,
 		return -EINVAL;
 	}
 
-	if ((args->start.srcdevid == 0 && args->start.srcdev_name[0] == '\0') ||
-	    args->start.tgtdev_name[0] == '\0')
-		return -EINVAL;
-
 	/* the disk copy procedure reuses the scrub code */
 	mutex_lock(&fs_info->volume_mutex);
 	ret = btrfs_find_device_by_user_input(root, args->start.srcdevid,
diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index 40bbe0a2715b..d74260567bea 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -2113,6 +2113,9 @@ int btrfs_find_device_by_user_input(struct btrfs_root *root, u64 srcdevid,
 		if (!*device)
 			ret = -ENOENT;
 	} else {
+		if (!srcdev_name || !srcdev_name[0])
+			return -EINVAL;
+
 		ret = btrfs_find_device_missing_or_by_path(root, srcdev_name,
 							   device);
 	}
-- 
cgit v1.2.3


From 42b674271566c26692c32f4ec1f4b4cf14d5046f Mon Sep 17 00:00:00 2001
From: Anand Jain <anand.jain@oracle.com>
Date: Sat, 13 Feb 2016 10:01:38 +0800
Subject: btrfs: make use of btrfs_scratch_superblocks() in btrfs_rm_device()

With the previous patches now the btrfs_scratch_superblocks() is ready to
be used in btrfs_rm_device() so use it.

Signed-off-by: Anand Jain <anand.jain@oracle.com>
[ use GFP_KERNEL ]
Signed-off-by: David Sterba <dsterba@suse.com>
---
 fs/btrfs/volumes.c | 77 +++++++++---------------------------------------------
 1 file changed, 13 insertions(+), 64 deletions(-)

(limited to 'fs')

diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index d74260567bea..8264b06756e6 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -1752,13 +1752,11 @@ int btrfs_rm_device(struct btrfs_root *root, char *device_path)
 {
 	struct btrfs_device *device;
 	struct btrfs_device *next_device;
-	struct block_device *bdev = NULL;
-	struct buffer_head *bh = NULL;
-	struct btrfs_super_block *disk_super = NULL;
 	struct btrfs_fs_devices *cur_devices;
 	u64 num_devices;
 	int ret = 0;
 	bool clear_super = false;
+	char *dev_name = NULL;
 
 	mutex_lock(&uuid_mutex);
 
@@ -1786,6 +1784,11 @@ int btrfs_rm_device(struct btrfs_root *root, char *device_path)
 		list_del_init(&device->dev_alloc_list);
 		device->fs_devices->rw_devices--;
 		unlock_chunks(root);
+		dev_name = kstrdup(device->name->str, GFP_KERNEL);
+		if (!dev_name) {
+			ret = -ENOMEM;
+			goto error_undo;
+		}
 		clear_super = true;
 	}
 
@@ -1869,73 +1872,19 @@ int btrfs_rm_device(struct btrfs_root *root, char *device_path)
 	 * remove it from the devices list and zero out the old super
 	 */
 	if (clear_super) {
-		u64 bytenr;
-		int i;
-
-		if (!disk_super) {
-			ret = btrfs_get_bdev_and_sb(device_path,
-					FMODE_WRITE | FMODE_EXCL,
-					root->fs_info->bdev_holder, 0,
-					&bdev, &bh);
-			if (ret) {
-				/*
-				 * It could be a failed device ok for clear_super
-				 * to fail. So return success
-				 */
-				ret = 0;
-				goto out;
-			}
-
-			disk_super = (struct btrfs_super_block *)bh->b_data;
-		}
-		/* make sure this device isn't detected as part of
-		 * the FS anymore
-		 */
-		memset(&disk_super->magic, 0, sizeof(disk_super->magic));
-		set_buffer_dirty(bh);
-		sync_dirty_buffer(bh);
-		brelse(bh);
-
-		/* clear the mirror copies of super block on the disk
-		 * being removed, 0th copy is been taken care above and
-		 * the below would take of the rest
-		 */
-		for (i = 1; i < BTRFS_SUPER_MIRROR_MAX; i++) {
-			bytenr = btrfs_sb_offset(i);
-			if (bytenr + BTRFS_SUPER_INFO_SIZE >=
-					i_size_read(bdev->bd_inode))
-				break;
-
-			bh = __bread(bdev, bytenr / 4096,
-					BTRFS_SUPER_INFO_SIZE);
-			if (!bh)
-				continue;
+		struct block_device *bdev;
 
-			disk_super = (struct btrfs_super_block *)bh->b_data;
-
-			if (btrfs_super_bytenr(disk_super) != bytenr ||
-				btrfs_super_magic(disk_super) != BTRFS_MAGIC) {
-				brelse(bh);
-				continue;
-			}
-			memset(&disk_super->magic, 0,
-						sizeof(disk_super->magic));
-			set_buffer_dirty(bh);
-			sync_dirty_buffer(bh);
-			brelse(bh);
-		}
-
-		if (bdev) {
-			/* Notify udev that device has changed */
-			btrfs_kobject_uevent(bdev, KOBJ_CHANGE);
-
-			/* Update ctime/mtime for device path for libblkid */
-			update_dev_time(device_path);
+		bdev = blkdev_get_by_path(dev_name, FMODE_READ | FMODE_EXCL,
+						root->fs_info->bdev_holder);
+		if (!IS_ERR(bdev)) {
+			btrfs_scratch_superblocks(bdev, dev_name);
 			blkdev_put(bdev, FMODE_READ | FMODE_EXCL);
 		}
 	}
 
 out:
+	kfree(dev_name);
+
 	mutex_unlock(&uuid_mutex);
 	return ret;
 
-- 
cgit v1.2.3


From 6b526ed70cf189660d009ea6f17af77a9cca0f38 Mon Sep 17 00:00:00 2001
From: Anand Jain <anand.jain@oracle.com>
Date: Sat, 13 Feb 2016 10:01:39 +0800
Subject: btrfs: introduce device delete by devid

This introduces new ioctl BTRFS_IOC_RM_DEV_V2, which uses enhanced struct
btrfs_ioctl_vol_args_v2 to carry devid as an user argument.

The patch won't delete the old ioctl interface and so kernel remains
backward compatible with user land progs.

Test case/script:
echo "0 $(blockdev --getsz /dev/sdf) linear /dev/sdf 0" | dmsetup create bad_disk
mkfs.btrfs -f -d raid1 -m raid1 /dev/sdd /dev/sde /dev/mapper/bad_disk
mount /dev/sdd /btrfs
dmsetup suspend bad_disk
echo "0 $(blockdev --getsz /dev/sdf) error /dev/sdf 0" | dmsetup load bad_disk
dmsetup resume bad_disk
echo "bad disk failed. now deleting/replacing"
btrfs dev del  3  /btrfs
echo $?
btrfs fi show /btrfs
umount /btrfs
btrfs-show-super /dev/sdd | egrep num_device
dmsetup remove bad_disk
wipefs -a /dev/sdf

Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reported-by: Martin <m_btrfs@ml1.co.uk>
[ adjust messages, s/disk/device/ ]
Signed-off-by: David Sterba <dsterba@suse.com>
---
 fs/btrfs/ioctl.c           | 58 +++++++++++++++++++++++++++++++++++++++++++++-
 fs/btrfs/volumes.c         |  4 ++--
 fs/btrfs/volumes.h         |  2 +-
 include/uapi/linux/btrfs.h | 14 ++++++++++-
 4 files changed, 73 insertions(+), 5 deletions(-)

(limited to 'fs')

diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index 5a23806ae418..7cf0f6328d99 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -2667,6 +2667,60 @@ out:
 	return ret;
 }
 
+static long btrfs_ioctl_rm_dev_v2(struct file *file, void __user *arg)
+{
+	struct btrfs_root *root = BTRFS_I(file_inode(file))->root;
+	struct btrfs_ioctl_vol_args_v2 *vol_args;
+	int ret;
+
+	if (!capable(CAP_SYS_ADMIN))
+		return -EPERM;
+
+	ret = mnt_want_write_file(file);
+	if (ret)
+		return ret;
+
+	vol_args = memdup_user(arg, sizeof(*vol_args));
+	if (IS_ERR(vol_args)) {
+		ret = PTR_ERR(vol_args);
+		goto err_drop;
+	}
+
+	/* Check for compatibility reject unknown flags */
+	if (vol_args->flags & ~BTRFS_VOL_ARG_V2_FLAGS)
+		return -ENOTTY;
+
+	if (atomic_xchg(&root->fs_info->mutually_exclusive_operation_running,
+			1)) {
+		ret = BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS;
+		goto out;
+	}
+
+	mutex_lock(&root->fs_info->volume_mutex);
+	if (vol_args->flags & BTRFS_DEVICE_BY_ID) {
+		ret = btrfs_rm_device(root, NULL, vol_args->devid);
+	} else {
+		vol_args->name[BTRFS_SUBVOL_NAME_MAX] = '\0';
+		ret = btrfs_rm_device(root, vol_args->name, 0);
+	}
+	mutex_unlock(&root->fs_info->volume_mutex);
+	atomic_set(&root->fs_info->mutually_exclusive_operation_running, 0);
+
+	if (!ret) {
+		if (vol_args->flags & BTRFS_DEVICE_BY_ID)
+			btrfs_info(root->fs_info, "device deleted: id %llu",
+					vol_args->devid);
+		else
+			btrfs_info(root->fs_info, "device deleted: %s",
+					vol_args->name);
+	}
+out:
+	kfree(vol_args);
+err_drop:
+	mnt_drop_write_file(file);
+	return ret;
+}
+
 static long btrfs_ioctl_rm_dev(struct file *file, void __user *arg)
 {
 	struct btrfs_root *root = BTRFS_I(file_inode(file))->root;
@@ -2695,7 +2749,7 @@ static long btrfs_ioctl_rm_dev(struct file *file, void __user *arg)
 	}
 
 	mutex_lock(&root->fs_info->volume_mutex);
-	ret = btrfs_rm_device(root, vol_args->name);
+	ret = btrfs_rm_device(root, vol_args->name, 0);
 	mutex_unlock(&root->fs_info->volume_mutex);
 	atomic_set(&root->fs_info->mutually_exclusive_operation_running, 0);
 
@@ -5459,6 +5513,8 @@ long btrfs_ioctl(struct file *file, unsigned int
 		return btrfs_ioctl_add_dev(root, argp);
 	case BTRFS_IOC_RM_DEV:
 		return btrfs_ioctl_rm_dev(file, argp);
+	case BTRFS_IOC_RM_DEV_V2:
+		return btrfs_ioctl_rm_dev_v2(file, argp);
 	case BTRFS_IOC_FS_INFO:
 		return btrfs_ioctl_fs_info(root, argp);
 	case BTRFS_IOC_DEV_INFO:
diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index 8264b06756e6..1421d711629f 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -1748,7 +1748,7 @@ static int __check_raid_min_devices(struct btrfs_fs_info *fs_info)
 	return 0;
 }
 
-int btrfs_rm_device(struct btrfs_root *root, char *device_path)
+int btrfs_rm_device(struct btrfs_root *root, char *device_path, u64 devid)
 {
 	struct btrfs_device *device;
 	struct btrfs_device *next_device;
@@ -1764,7 +1764,7 @@ int btrfs_rm_device(struct btrfs_root *root, char *device_path)
 	if (ret)
 		goto out;
 
-	ret = btrfs_find_device_by_user_input(root, 0, device_path,
+	ret = btrfs_find_device_by_user_input(root, devid, device_path,
 				&device);
 	if (ret)
 		goto out;
diff --git a/fs/btrfs/volumes.h b/fs/btrfs/volumes.h
index 508739314e43..c73d027e2f8b 100644
--- a/fs/btrfs/volumes.h
+++ b/fs/btrfs/volumes.h
@@ -454,7 +454,7 @@ int btrfs_find_device_by_user_input(struct btrfs_root *root, u64 srcdevid,
 struct btrfs_device *btrfs_alloc_device(struct btrfs_fs_info *fs_info,
 					const u64 *devid,
 					const u8 *uuid);
-int btrfs_rm_device(struct btrfs_root *root, char *device_path);
+int btrfs_rm_device(struct btrfs_root *root, char *device_path, u64 devid);
 void btrfs_cleanup_fs_uuids(void);
 int btrfs_num_copies(struct btrfs_fs_info *fs_info, u64 logical, u64 len);
 int btrfs_grow_device(struct btrfs_trans_handle *trans,
diff --git a/include/uapi/linux/btrfs.h b/include/uapi/linux/btrfs.h
index dea893199257..396a4efca775 100644
--- a/include/uapi/linux/btrfs.h
+++ b/include/uapi/linux/btrfs.h
@@ -36,6 +36,13 @@ struct btrfs_ioctl_vol_args {
 #define BTRFS_SUBVOL_CREATE_ASYNC	(1ULL << 0)
 #define BTRFS_SUBVOL_RDONLY		(1ULL << 1)
 #define BTRFS_SUBVOL_QGROUP_INHERIT	(1ULL << 2)
+#define BTRFS_DEVICE_BY_ID		(1ULL << 3)
+#define BTRFS_VOL_ARG_V2_FLAGS				\
+			(BTRFS_SUBVOL_CREATE_ASYNC |	\
+			BTRFS_SUBVOL_RDONLY |		\
+			BTRFS_SUBVOL_QGROUP_INHERIT |	\
+			BTRFS_DEVICE_BY_ID)
+
 #define BTRFS_FSID_SIZE 16
 #define BTRFS_UUID_SIZE 16
 #define BTRFS_UUID_UNPARSED_SIZE	37
@@ -76,7 +83,10 @@ struct btrfs_ioctl_vol_args_v2 {
 		};
 		__u64 unused[4];
 	};
-	char name[BTRFS_SUBVOL_NAME_MAX + 1];
+	union {
+		char name[BTRFS_SUBVOL_NAME_MAX + 1];
+		u64 devid;
+	};
 };
 
 /*
@@ -659,5 +669,7 @@ static inline char *btrfs_err_str(enum btrfs_err_code err_code)
 				   struct btrfs_ioctl_feature_flags[2])
 #define BTRFS_IOC_GET_SUPPORTED_FEATURES _IOR(BTRFS_IOCTL_MAGIC, 57, \
 				   struct btrfs_ioctl_feature_flags[3])
+#define BTRFS_IOC_RM_DEV_V2 _IOW(BTRFS_IOCTL_MAGIC, 58, \
+				   struct btrfs_ioctl_vol_args_v2)
 
 #endif /* _UAPI_LINUX_BTRFS_H */
-- 
cgit v1.2.3


From 02feae3c5525771878461b90edd2ba38fd3f5359 Mon Sep 17 00:00:00 2001
From: Anand Jain <anand.jain@oracle.com>
Date: Sat, 13 Feb 2016 10:01:40 +0800
Subject: btrfs: optimize check for stale device

Optimize check for stale device to only be checked when there is device
added or changed. If there is no update to the device, there is no need
to call btrfs_free_stale_device().

Signed-off-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
---
 fs/btrfs/volumes.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

(limited to 'fs')

diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index 1421d711629f..2fdd2d3322aa 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -699,7 +699,8 @@ static noinline int device_list_add(const char *path,
 	 * if there is new btrfs on an already registered device,
 	 * then remove the stale device entry.
 	 */
-	btrfs_free_stale_device(device);
+	if (ret > 0)
+		btrfs_free_stale_device(device);
 
 	*fs_devices_ret = fs_devices;
 
-- 
cgit v1.2.3


From f47ab2588e424cb4898b75ace1e2323ddd18b990 Mon Sep 17 00:00:00 2001
From: David Sterba <dsterba@suse.com>
Date: Mon, 15 Feb 2016 15:28:48 +0100
Subject: btrfs: rename __check_raid_min_devices

Underscores are for special functions, use the full prefix for better
stacktrace recognition.

Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
---
 fs/btrfs/volumes.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

(limited to 'fs')

diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index 2fdd2d3322aa..9051b4472bea 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -1706,7 +1706,7 @@ out:
 	return ret;
 }
 
-static int __check_raid_min_devices(struct btrfs_fs_info *fs_info)
+static int btrfs_check_raid_min_devices(struct btrfs_fs_info *fs_info)
 {
 	u64 all_avail;
 	u64 num_devices;
@@ -1761,7 +1761,7 @@ int btrfs_rm_device(struct btrfs_root *root, char *device_path, u64 devid)
 
 	mutex_lock(&uuid_mutex);
 
-	ret = __check_raid_min_devices(root->fs_info);
+	ret = btrfs_check_raid_min_devices(root->fs_info);
 	if (ret)
 		goto out;
 
-- 
cgit v1.2.3


From 3cc31a0d5bc77e35229671307eba5ea5c4c4cb9d Mon Sep 17 00:00:00 2001
From: David Sterba <dsterba@suse.com>
Date: Mon, 15 Feb 2016 16:00:26 +0100
Subject: btrfs: pass number of devices to btrfs_check_raid_min_devices

Before this patch, btrfs_check_raid_min_devices would do an off-by-one
check of the constraints and not the miminmum check, as its name
suggests. This is not a problem if the only caller is device remove, but
would be confusing for others.

Add an argument with the exact number and let the caller(s) decide if
this needs any adjustments, like when device replace is running.

Reviewed-by: Anand Jain <anand.jain@oracle.com>
Tested-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
---
 fs/btrfs/volumes.c | 35 ++++++++++++++++++++---------------
 1 file changed, 20 insertions(+), 15 deletions(-)

(limited to 'fs')

diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index 9051b4472bea..e966f0ce07f8 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -1706,20 +1706,17 @@ out:
 	return ret;
 }
 
-static int btrfs_check_raid_min_devices(struct btrfs_fs_info *fs_info)
+/*
+ * Verify that @num_devices satisfies the RAID profile constraints in the whole
+ * filesystem. It's up to the caller to adjust that number regarding eg. device
+ * replace.
+ */
+static int btrfs_check_raid_min_devices(struct btrfs_fs_info *fs_info,
+		u64 num_devices)
 {
 	u64 all_avail;
-	u64 num_devices;
 	unsigned seq;
 
-	num_devices = fs_info->fs_devices->num_devices;
-	btrfs_dev_replace_lock(&fs_info->dev_replace, 0);
-	if (btrfs_dev_replace_is_ongoing(&fs_info->dev_replace)) {
-		WARN_ON(num_devices < 1);
-		num_devices--;
-	}
-	btrfs_dev_replace_unlock(&fs_info->dev_replace, 0);
-
 	do {
 		seq = read_seqbegin(&fs_info->profiles_lock);
 
@@ -1728,21 +1725,21 @@ static int btrfs_check_raid_min_devices(struct btrfs_fs_info *fs_info)
 			    fs_info->avail_metadata_alloc_bits;
 	} while (read_seqretry(&fs_info->profiles_lock, seq));
 
-	if ((all_avail & BTRFS_BLOCK_GROUP_RAID10) && num_devices <= 4) {
+	if ((all_avail & BTRFS_BLOCK_GROUP_RAID10) && num_devices < 4) {
 		return BTRFS_ERROR_DEV_RAID10_MIN_NOT_MET;
 	}
 
-	if ((all_avail & BTRFS_BLOCK_GROUP_RAID1) && num_devices <= 2) {
+	if ((all_avail & BTRFS_BLOCK_GROUP_RAID1) && num_devices < 2) {
 		return BTRFS_ERROR_DEV_RAID1_MIN_NOT_MET;
 	}
 
 	if ((all_avail & BTRFS_BLOCK_GROUP_RAID5) &&
-	    fs_info->fs_devices->rw_devices <= 2) {
+	    fs_info->fs_devices->rw_devices < 2) {
 		return BTRFS_ERROR_DEV_RAID5_MIN_NOT_MET;
 	}
 
 	if ((all_avail & BTRFS_BLOCK_GROUP_RAID6) &&
-	    fs_info->fs_devices->rw_devices <= 3) {
+	    fs_info->fs_devices->rw_devices < 3) {
 		return BTRFS_ERROR_DEV_RAID6_MIN_NOT_MET;
 	}
 
@@ -1761,7 +1758,15 @@ int btrfs_rm_device(struct btrfs_root *root, char *device_path, u64 devid)
 
 	mutex_lock(&uuid_mutex);
 
-	ret = btrfs_check_raid_min_devices(root->fs_info);
+	num_devices = root->fs_info->fs_devices->num_devices;
+	btrfs_dev_replace_lock(&root->fs_info->dev_replace, 0);
+	if (btrfs_dev_replace_is_ongoing(&root->fs_info->dev_replace)) {
+		WARN_ON(num_devices < 1);
+		num_devices--;
+	}
+	btrfs_dev_replace_unlock(&root->fs_info->dev_replace, 0);
+
+	ret = btrfs_check_raid_min_devices(root->fs_info, num_devices - 1);
 	if (ret)
 		goto out;
 
-- 
cgit v1.2.3


From 621292bae6ae3b25cd3124b63603d01df4cccfb6 Mon Sep 17 00:00:00 2001
From: David Sterba <dsterba@suse.com>
Date: Mon, 15 Feb 2016 16:28:03 +0100
Subject: btrfs: introduce raid-type to error-code table, for minimum device
 constraint

Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
---
 fs/btrfs/volumes.c | 15 +++++++++++++++
 fs/btrfs/volumes.h |  2 +-
 2 files changed, 16 insertions(+), 1 deletion(-)

(limited to 'fs')

diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index e966f0ce07f8..6b38b72d678b 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -118,6 +118,21 @@ const u64 btrfs_raid_group[BTRFS_NR_RAID_TYPES] = {
 	[BTRFS_RAID_RAID6]  = BTRFS_BLOCK_GROUP_RAID6,
 };
 
+/*
+ * Table to convert BTRFS_RAID_* to the error code if minimum number of devices
+ * condition is not met. Zero means there's no corresponding
+ * BTRFS_ERROR_DEV_*_NOT_MET value.
+ */
+const int btrfs_raid_mindev_error[BTRFS_NR_RAID_TYPES] = {
+	[BTRFS_RAID_RAID10] = BTRFS_ERROR_DEV_RAID10_MIN_NOT_MET,
+	[BTRFS_RAID_RAID1]  = BTRFS_ERROR_DEV_RAID1_MIN_NOT_MET,
+	[BTRFS_RAID_DUP]    = 0,
+	[BTRFS_RAID_RAID0]  = 0,
+	[BTRFS_RAID_SINGLE] = 0,
+	[BTRFS_RAID_RAID5]  = BTRFS_ERROR_DEV_RAID5_MIN_NOT_MET,
+	[BTRFS_RAID_RAID6]  = BTRFS_ERROR_DEV_RAID6_MIN_NOT_MET,
+};
+
 static int init_first_rw_device(struct btrfs_trans_handle *trans,
 				struct btrfs_root *root,
 				struct btrfs_device *device);
diff --git a/fs/btrfs/volumes.h b/fs/btrfs/volumes.h
index c73d027e2f8b..a13a538cb01e 100644
--- a/fs/btrfs/volumes.h
+++ b/fs/btrfs/volumes.h
@@ -340,7 +340,7 @@ struct btrfs_raid_attr {
 };
 
 extern const struct btrfs_raid_attr btrfs_raid_array[BTRFS_NR_RAID_TYPES];
-
+extern const int btrfs_raid_mindev_error[BTRFS_NR_RAID_TYPES];
 extern const u64 btrfs_raid_group[BTRFS_NR_RAID_TYPES];
 
 struct map_lookup {
-- 
cgit v1.2.3


From 418775a22b4c67bd15915e043c3a8f29816799bd Mon Sep 17 00:00:00 2001
From: David Sterba <dsterba@suse.com>
Date: Mon, 15 Feb 2016 16:28:14 +0100
Subject: btrfs: use existing device constraints table btrfs_raid_array

We should avoid duplicating the device constraints, let's use the
btrfs_raid_array in btrfs_check_raid_min_devices.

Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
---
 fs/btrfs/volumes.c | 23 +++++++++--------------
 1 file changed, 9 insertions(+), 14 deletions(-)

(limited to 'fs')

diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index 6b38b72d678b..055fbebea199 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -1731,6 +1731,7 @@ static int btrfs_check_raid_min_devices(struct btrfs_fs_info *fs_info,
 {
 	u64 all_avail;
 	unsigned seq;
+	int i;
 
 	do {
 		seq = read_seqbegin(&fs_info->profiles_lock);
@@ -1740,22 +1741,16 @@ static int btrfs_check_raid_min_devices(struct btrfs_fs_info *fs_info,
 			    fs_info->avail_metadata_alloc_bits;
 	} while (read_seqretry(&fs_info->profiles_lock, seq));
 
-	if ((all_avail & BTRFS_BLOCK_GROUP_RAID10) && num_devices < 4) {
-		return BTRFS_ERROR_DEV_RAID10_MIN_NOT_MET;
-	}
-
-	if ((all_avail & BTRFS_BLOCK_GROUP_RAID1) && num_devices < 2) {
-		return BTRFS_ERROR_DEV_RAID1_MIN_NOT_MET;
-	}
+	for (i = 0; i < BTRFS_NR_RAID_TYPES; i++) {
+		if (!(all_avail & btrfs_raid_group[i]))
+			continue;
 
-	if ((all_avail & BTRFS_BLOCK_GROUP_RAID5) &&
-	    fs_info->fs_devices->rw_devices < 2) {
-		return BTRFS_ERROR_DEV_RAID5_MIN_NOT_MET;
-	}
+		if (num_devices < btrfs_raid_array[i].devs_min) {
+			int ret = btrfs_raid_mindev_error[i];
 
-	if ((all_avail & BTRFS_BLOCK_GROUP_RAID6) &&
-	    fs_info->fs_devices->rw_devices < 3) {
-		return BTRFS_ERROR_DEV_RAID6_MIN_NOT_MET;
+			if (ret)
+				return ret;
+		}
 	}
 
 	return 0;
-- 
cgit v1.2.3


From 5c5c0df05deaebcdcc9bb31bdca3812a7c22230f Mon Sep 17 00:00:00 2001
From: David Sterba <dsterba@suse.com>
Date: Mon, 15 Feb 2016 16:39:55 +0100
Subject: btrfs: rename btrfs_find_device_by_user_input

For clarity how we are going to find the device, let's call it a device
specifier, devspec for short. Also rename the arguments that are a
leftover from previous function purpose.

Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
---
 fs/btrfs/dev-replace.c |  2 +-
 fs/btrfs/volumes.c     | 17 ++++++++++-------
 fs/btrfs/volumes.h     |  4 ++--
 3 files changed, 13 insertions(+), 10 deletions(-)

(limited to 'fs')

diff --git a/fs/btrfs/dev-replace.c b/fs/btrfs/dev-replace.c
index fdd2880707df..b7f5f4aa6e86 100644
--- a/fs/btrfs/dev-replace.c
+++ b/fs/btrfs/dev-replace.c
@@ -322,7 +322,7 @@ int btrfs_dev_replace_start(struct btrfs_root *root,
 
 	/* the disk copy procedure reuses the scrub code */
 	mutex_lock(&fs_info->volume_mutex);
-	ret = btrfs_find_device_by_user_input(root, args->start.srcdevid,
+	ret = btrfs_find_device_by_devspec(root, args->start.srcdevid,
 					    args->start.srcdev_name,
 					    &src_device);
 	if (ret) {
diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index 055fbebea199..e43b01e438b1 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -1780,7 +1780,7 @@ int btrfs_rm_device(struct btrfs_root *root, char *device_path, u64 devid)
 	if (ret)
 		goto out;
 
-	ret = btrfs_find_device_by_user_input(root, devid, device_path,
+	ret = btrfs_find_device_by_devspec(root, devid, device_path,
 				&device);
 	if (ret)
 		goto out;
@@ -2065,23 +2065,26 @@ int btrfs_find_device_missing_or_by_path(struct btrfs_root *root,
 	}
 }
 
-int btrfs_find_device_by_user_input(struct btrfs_root *root, u64 srcdevid,
-					 char *srcdev_name,
+/*
+ * Lookup a device given by device id, or the path if the id is 0.
+ */
+int btrfs_find_device_by_devspec(struct btrfs_root *root, u64 devid,
+					 char *devpath,
 					 struct btrfs_device **device)
 {
 	int ret;
 
-	if (srcdevid) {
+	if (devid) {
 		ret = 0;
-		*device = btrfs_find_device(root->fs_info, srcdevid, NULL,
+		*device = btrfs_find_device(root->fs_info, devid, NULL,
 					    NULL);
 		if (!*device)
 			ret = -ENOENT;
 	} else {
-		if (!srcdev_name || !srcdev_name[0])
+		if (!devpath || !devpath[0])
 			return -EINVAL;
 
-		ret = btrfs_find_device_missing_or_by_path(root, srcdev_name,
+		ret = btrfs_find_device_missing_or_by_path(root, devpath,
 							   device);
 	}
 	return ret;
diff --git a/fs/btrfs/volumes.h b/fs/btrfs/volumes.h
index a13a538cb01e..febdb7bc9370 100644
--- a/fs/btrfs/volumes.h
+++ b/fs/btrfs/volumes.h
@@ -448,8 +448,8 @@ void btrfs_close_extra_devices(struct btrfs_fs_devices *fs_devices, int step);
 int btrfs_find_device_missing_or_by_path(struct btrfs_root *root,
 					 char *device_path,
 					 struct btrfs_device **device);
-int btrfs_find_device_by_user_input(struct btrfs_root *root, u64 srcdevid,
-					 char *srcdev_name,
+int btrfs_find_device_by_devspec(struct btrfs_root *root, u64 devid,
+					 char *devpath,
 					 struct btrfs_device **device);
 struct btrfs_device *btrfs_alloc_device(struct btrfs_fs_info *fs_info,
 					const u64 *devid,
-- 
cgit v1.2.3


From 735654ea91a06a30bfe05fdfd09c8895abf6c1bf Mon Sep 17 00:00:00 2001
From: David Sterba <dsterba@suse.com>
Date: Mon, 15 Feb 2016 18:15:21 +0100
Subject: btrfs: rename flags for vol args v2

Rename BTRFS_DEVICE_BY_ID so it's more descriptive that we specify the
device by id, it'll be part of the public API. The mask of supported
flags is also renamed, only for internal use.

The error code for unknown flags is EOPNOTSUPP, fixed.

Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
---
 fs/btrfs/ioctl.c           | 8 ++++----
 include/uapi/linux/btrfs.h | 7 ++++---
 2 files changed, 8 insertions(+), 7 deletions(-)

(limited to 'fs')

diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index 7cf0f6328d99..65903ec5e1c0 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -2687,8 +2687,8 @@ static long btrfs_ioctl_rm_dev_v2(struct file *file, void __user *arg)
 	}
 
 	/* Check for compatibility reject unknown flags */
-	if (vol_args->flags & ~BTRFS_VOL_ARG_V2_FLAGS)
-		return -ENOTTY;
+	if (vol_args->flags & ~BTRFS_VOL_ARG_V2_FLAGS_SUPPORTED)
+		return -EOPNOTSUPP;
 
 	if (atomic_xchg(&root->fs_info->mutually_exclusive_operation_running,
 			1)) {
@@ -2697,7 +2697,7 @@ static long btrfs_ioctl_rm_dev_v2(struct file *file, void __user *arg)
 	}
 
 	mutex_lock(&root->fs_info->volume_mutex);
-	if (vol_args->flags & BTRFS_DEVICE_BY_ID) {
+	if (vol_args->flags & BTRFS_DEVICE_SPEC_BY_ID) {
 		ret = btrfs_rm_device(root, NULL, vol_args->devid);
 	} else {
 		vol_args->name[BTRFS_SUBVOL_NAME_MAX] = '\0';
@@ -2707,7 +2707,7 @@ static long btrfs_ioctl_rm_dev_v2(struct file *file, void __user *arg)
 	atomic_set(&root->fs_info->mutually_exclusive_operation_running, 0);
 
 	if (!ret) {
-		if (vol_args->flags & BTRFS_DEVICE_BY_ID)
+		if (vol_args->flags & BTRFS_DEVICE_SPEC_BY_ID)
 			btrfs_info(root->fs_info, "device deleted: id %llu",
 					vol_args->devid);
 		else
diff --git a/include/uapi/linux/btrfs.h b/include/uapi/linux/btrfs.h
index 396a4efca775..3975e683af72 100644
--- a/include/uapi/linux/btrfs.h
+++ b/include/uapi/linux/btrfs.h
@@ -36,12 +36,13 @@ struct btrfs_ioctl_vol_args {
 #define BTRFS_SUBVOL_CREATE_ASYNC	(1ULL << 0)
 #define BTRFS_SUBVOL_RDONLY		(1ULL << 1)
 #define BTRFS_SUBVOL_QGROUP_INHERIT	(1ULL << 2)
-#define BTRFS_DEVICE_BY_ID		(1ULL << 3)
-#define BTRFS_VOL_ARG_V2_FLAGS				\
+#define BTRFS_DEVICE_SPEC_BY_ID		(1ULL << 3)
+
+#define BTRFS_VOL_ARG_V2_FLAGS_SUPPORTED		\
 			(BTRFS_SUBVOL_CREATE_ASYNC |	\
 			BTRFS_SUBVOL_RDONLY |		\
 			BTRFS_SUBVOL_QGROUP_INHERIT |	\
-			BTRFS_DEVICE_BY_ID)
+			BTRFS_DEVICE_SPEC_BY_ID)
 
 #define BTRFS_FSID_SIZE 16
 #define BTRFS_UUID_SIZE 16
-- 
cgit v1.2.3


From fc23c246d72d21385be115305d1cb85fcc34acad Mon Sep 17 00:00:00 2001
From: Anand Jain <anand.jain@oracle.com>
Date: Thu, 24 Mar 2016 18:48:12 +0800
Subject: btrfs: use fs_info directly

Local variable fs_info, contains root->fs_info, use it.

Signed-off-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
---
 fs/btrfs/dev-replace.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

(limited to 'fs')

diff --git a/fs/btrfs/dev-replace.c b/fs/btrfs/dev-replace.c
index b7f5f4aa6e86..1a3d24592859 100644
--- a/fs/btrfs/dev-replace.c
+++ b/fs/btrfs/dev-replace.c
@@ -368,7 +368,7 @@ int btrfs_dev_replace_start(struct btrfs_root *root,
 	WARN_ON(!tgt_device);
 	dev_replace->tgtdev = tgt_device;
 
-	btrfs_info_in_rcu(root->fs_info,
+	btrfs_info_in_rcu(fs_info,
 		      "dev_replace from %s (devid %llu) to %s started",
 		      src_device->missing ? "<missing disk>" :
 		        rcu_str_deref(src_device->name),
@@ -394,9 +394,9 @@ int btrfs_dev_replace_start(struct btrfs_root *root,
 
 	ret = btrfs_sysfs_add_device_link(tgt_device->fs_devices, tgt_device);
 	if (ret)
-		btrfs_err(root->fs_info, "kobj add dev failed %d\n", ret);
+		btrfs_err(fs_info, "kobj add dev failed %d\n", ret);
 
-	btrfs_wait_ordered_roots(root->fs_info, -1);
+	btrfs_wait_ordered_roots(fs_info, -1);
 
 	/* force writing the updated state information to disk */
 	trans = btrfs_start_transaction(root, 0);
@@ -414,7 +414,7 @@ int btrfs_dev_replace_start(struct btrfs_root *root,
 			      btrfs_device_get_total_bytes(src_device),
 			      &dev_replace->scrub_progress, 0, 1);
 
-	ret = btrfs_dev_replace_finishing(root->fs_info, ret);
+	ret = btrfs_dev_replace_finishing(fs_info, ret);
 	/* don't warn if EINPROGRESS, someone else might be running scrub */
 	if (ret == -EINPROGRESS) {
 		args->result = BTRFS_IOCTL_DEV_REPLACE_RESULT_SCRUB_INPROGRESS;
-- 
cgit v1.2.3


From b5255456c529155730c837f8cfcea47e8feb85ca Mon Sep 17 00:00:00 2001
From: Anand Jain <anand.jain@oracle.com>
Date: Thu, 24 Mar 2016 18:48:14 +0800
Subject: btrfs: refactor btrfs_dev_replace_start for reuse

A refactor patch, and avoids user input verification in the
btrfs_dev_replace_start(), and so this function can be reused.

Signed-off-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
---
 fs/btrfs/dev-replace.c | 58 ++++++++++++++++++++++++++++++++------------------
 fs/btrfs/dev-replace.h |  4 +++-
 fs/btrfs/ioctl.c       |  2 +-
 3 files changed, 41 insertions(+), 23 deletions(-)

(limited to 'fs')

diff --git a/fs/btrfs/dev-replace.c b/fs/btrfs/dev-replace.c
index 1a3d24592859..5aebedf12b5f 100644
--- a/fs/btrfs/dev-replace.c
+++ b/fs/btrfs/dev-replace.c
@@ -302,8 +302,8 @@ void btrfs_after_dev_replace_commit(struct btrfs_fs_info *fs_info)
 		dev_replace->cursor_left_last_write_of_item;
 }
 
-int btrfs_dev_replace_start(struct btrfs_root *root,
-			    struct btrfs_ioctl_dev_replace_args *args)
+int btrfs_dev_replace_start(struct btrfs_root *root, char *tgtdev_name,
+				u64 srcdevid, char *srcdev_name, int read_src)
 {
 	struct btrfs_trans_handle *trans;
 	struct btrfs_fs_info *fs_info = root->fs_info;
@@ -312,25 +312,16 @@ int btrfs_dev_replace_start(struct btrfs_root *root,
 	struct btrfs_device *tgt_device = NULL;
 	struct btrfs_device *src_device = NULL;
 
-	switch (args->start.cont_reading_from_srcdev_mode) {
-	case BTRFS_IOCTL_DEV_REPLACE_CONT_READING_FROM_SRCDEV_MODE_ALWAYS:
-	case BTRFS_IOCTL_DEV_REPLACE_CONT_READING_FROM_SRCDEV_MODE_AVOID:
-		break;
-	default:
-		return -EINVAL;
-	}
-
 	/* the disk copy procedure reuses the scrub code */
 	mutex_lock(&fs_info->volume_mutex);
-	ret = btrfs_find_device_by_devspec(root, args->start.srcdevid,
-					    args->start.srcdev_name,
-					    &src_device);
+	ret = btrfs_find_device_by_devspec(root, srcdevid,
+					    srcdev_name, &src_device);
 	if (ret) {
 		mutex_unlock(&fs_info->volume_mutex);
 		return ret;
 	}
 
-	ret = btrfs_init_dev_replace_tgtdev(root, args->start.tgtdev_name,
+	ret = btrfs_init_dev_replace_tgtdev(root, tgtdev_name,
 					    src_device, &tgt_device);
 	mutex_unlock(&fs_info->volume_mutex);
 	if (ret)
@@ -357,12 +348,11 @@ int btrfs_dev_replace_start(struct btrfs_root *root,
 		break;
 	case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED:
 	case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED:
-		args->result = BTRFS_IOCTL_DEV_REPLACE_RESULT_ALREADY_STARTED;
+		ret = BTRFS_IOCTL_DEV_REPLACE_RESULT_ALREADY_STARTED;
 		goto leave;
 	}
 
-	dev_replace->cont_reading_from_srcdev_mode =
-		args->start.cont_reading_from_srcdev_mode;
+	dev_replace->cont_reading_from_srcdev_mode = read_src;
 	WARN_ON(!src_device);
 	dev_replace->srcdev = src_device;
 	WARN_ON(!tgt_device);
@@ -389,7 +379,6 @@ int btrfs_dev_replace_start(struct btrfs_root *root,
 	dev_replace->item_needs_writeback = 1;
 	atomic64_set(&dev_replace->num_write_errors, 0);
 	atomic64_set(&dev_replace->num_uncorrectable_read_errors, 0);
-	args->result = BTRFS_IOCTL_DEV_REPLACE_RESULT_NO_ERROR;
 	btrfs_dev_replace_unlock(dev_replace, 1);
 
 	ret = btrfs_sysfs_add_device_link(tgt_device->fs_devices, tgt_device);
@@ -415,10 +404,8 @@ int btrfs_dev_replace_start(struct btrfs_root *root,
 			      &dev_replace->scrub_progress, 0, 1);
 
 	ret = btrfs_dev_replace_finishing(fs_info, ret);
-	/* don't warn if EINPROGRESS, someone else might be running scrub */
 	if (ret == -EINPROGRESS) {
-		args->result = BTRFS_IOCTL_DEV_REPLACE_RESULT_SCRUB_INPROGRESS;
-		ret = 0;
+		ret = BTRFS_IOCTL_DEV_REPLACE_RESULT_SCRUB_INPROGRESS;
 	} else {
 		WARN_ON(ret);
 	}
@@ -433,6 +420,35 @@ leave:
 	return ret;
 }
 
+int btrfs_dev_replace_by_ioctl(struct btrfs_root *root,
+			    struct btrfs_ioctl_dev_replace_args *args)
+{
+	int ret;
+
+	switch (args->start.cont_reading_from_srcdev_mode) {
+	case BTRFS_IOCTL_DEV_REPLACE_CONT_READING_FROM_SRCDEV_MODE_ALWAYS:
+	case BTRFS_IOCTL_DEV_REPLACE_CONT_READING_FROM_SRCDEV_MODE_AVOID:
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	if ((args->start.srcdevid == 0 && args->start.srcdev_name[0] == '\0') ||
+	    args->start.tgtdev_name[0] == '\0')
+		return -EINVAL;
+
+	ret = btrfs_dev_replace_start(root, args->start.tgtdev_name,
+					args->start.srcdevid,
+					args->start.srcdev_name,
+					args->start.cont_reading_from_srcdev_mode);
+	args->result = ret;
+	/* don't warn if EINPROGRESS, someone else might be running scrub */
+	if (ret == BTRFS_IOCTL_DEV_REPLACE_RESULT_SCRUB_INPROGRESS)
+		ret = 0;
+
+	return ret;
+}
+
 /*
  * blocked until all flighting bios are finished.
  */
diff --git a/fs/btrfs/dev-replace.h b/fs/btrfs/dev-replace.h
index 29e3ef5f96bd..e922b42d91df 100644
--- a/fs/btrfs/dev-replace.h
+++ b/fs/btrfs/dev-replace.h
@@ -25,8 +25,10 @@ int btrfs_init_dev_replace(struct btrfs_fs_info *fs_info);
 int btrfs_run_dev_replace(struct btrfs_trans_handle *trans,
 			  struct btrfs_fs_info *fs_info);
 void btrfs_after_dev_replace_commit(struct btrfs_fs_info *fs_info);
-int btrfs_dev_replace_start(struct btrfs_root *root,
+int btrfs_dev_replace_by_ioctl(struct btrfs_root *root,
 			    struct btrfs_ioctl_dev_replace_args *args);
+int btrfs_dev_replace_start(struct btrfs_root *root, char *tgtdev_name,
+				u64 srcdevid, char *srcdev_name, int read_src);
 void btrfs_dev_replace_status(struct btrfs_fs_info *fs_info,
 			      struct btrfs_ioctl_dev_replace_args *args);
 int btrfs_dev_replace_cancel(struct btrfs_fs_info *fs_info,
diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index 65903ec5e1c0..36b1ed223509 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -4430,7 +4430,7 @@ static long btrfs_ioctl_dev_replace(struct btrfs_root *root, void __user *arg)
 			1)) {
 			ret = BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS;
 		} else {
-			ret = btrfs_dev_replace_start(root, p);
+			ret = btrfs_dev_replace_by_ioctl(root, p);
 			atomic_set(
 			 &root->fs_info->mutually_exclusive_operation_running,
 			 0);
-- 
cgit v1.2.3


From 8ed01abe7da6af62f2089da9a4c1fe839dc638f5 Mon Sep 17 00:00:00 2001
From: Anand Jain <anand.jain@oracle.com>
Date: Thu, 14 Apr 2016 18:24:10 +0800
Subject: btrfs: s_bdev is not null after missing replace

Yauhen reported in the ML that s_bdev is null at mount, and
s_bdev gets updated to some device when missing device is
replaced, as because bdev is null for missing device, things
gets matched up. Fix this by checking if s_bdev is set. I
didn't want to completely remove updating s_bdev because
the future multi device support at vfs layer may need it.

Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reported-by: Yauhen Kharuzhy <yauhen.kharuzhy@zavadatar.com>
Signed-off-by: David Sterba <dsterba@suse.com>
---
 fs/btrfs/dev-replace.c | 3 ++-
 fs/btrfs/volumes.c     | 6 ++++--
 2 files changed, 6 insertions(+), 3 deletions(-)

(limited to 'fs')

diff --git a/fs/btrfs/dev-replace.c b/fs/btrfs/dev-replace.c
index 5aebedf12b5f..c93eec9ca433 100644
--- a/fs/btrfs/dev-replace.c
+++ b/fs/btrfs/dev-replace.c
@@ -569,7 +569,8 @@ static int btrfs_dev_replace_finishing(struct btrfs_fs_info *fs_info,
 	ASSERT(list_empty(&src_device->resized_list));
 	tgt_device->commit_total_bytes = src_device->commit_total_bytes;
 	tgt_device->commit_bytes_used = src_device->bytes_used;
-	if (fs_info->sb->s_bdev == src_device->bdev)
+	if (fs_info->sb->s_bdev &&
+		(fs_info->sb->s_bdev == src_device->bdev))
 		fs_info->sb->s_bdev = tgt_device->bdev;
 	if (fs_info->fs_devices->latest_bdev == src_device->bdev)
 		fs_info->fs_devices->latest_bdev = tgt_device->bdev;
diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index e43b01e438b1..41bc384f3483 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -1848,7 +1848,8 @@ int btrfs_rm_device(struct btrfs_root *root, char *device_path, u64 devid)
 
 	next_device = list_entry(root->fs_info->fs_devices->devices.next,
 				 struct btrfs_device, dev_list);
-	if (device->bdev == root->fs_info->sb->s_bdev)
+	if (root->fs_info->sb->s_bdev &&
+		(root->fs_info->sb->s_bdev == device->bdev))
 		root->fs_info->sb->s_bdev = next_device->bdev;
 	if (device->bdev == root->fs_info->fs_devices->latest_bdev)
 		root->fs_info->fs_devices->latest_bdev = next_device->bdev;
@@ -1996,7 +1997,8 @@ void btrfs_destroy_dev_replace_tgtdev(struct btrfs_fs_info *fs_info,
 
 	next_device = list_entry(fs_info->fs_devices->devices.next,
 				 struct btrfs_device, dev_list);
-	if (tgtdev->bdev == fs_info->sb->s_bdev)
+	if (fs_info->sb->s_bdev &&
+		(tgtdev->bdev == fs_info->sb->s_bdev))
 		fs_info->sb->s_bdev = next_device->bdev;
 	if (tgtdev->bdev == fs_info->fs_devices->latest_bdev)
 		fs_info->fs_devices->latest_bdev = next_device->bdev;
-- 
cgit v1.2.3


From 88acff64c621aaeee2a4fe0ed124c77358069bce Mon Sep 17 00:00:00 2001
From: Anand Jain <anand.jain@oracle.com>
Date: Tue, 3 May 2016 17:44:43 +0800
Subject: btrfs: cleanup assigning next active device with a check

Creates helper fucntion as needed by the device delete
and replace operations. Also now it checks if the next
device being assigned is an active device.

Signed-off-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
---
 fs/btrfs/dev-replace.c |  8 +++----
 fs/btrfs/volumes.c     | 60 ++++++++++++++++++++++++++++++++++++--------------
 fs/btrfs/volumes.h     |  2 ++
 3 files changed, 48 insertions(+), 22 deletions(-)

(limited to 'fs')

diff --git a/fs/btrfs/dev-replace.c b/fs/btrfs/dev-replace.c
index c93eec9ca433..1f193f742f21 100644
--- a/fs/btrfs/dev-replace.c
+++ b/fs/btrfs/dev-replace.c
@@ -569,11 +569,9 @@ static int btrfs_dev_replace_finishing(struct btrfs_fs_info *fs_info,
 	ASSERT(list_empty(&src_device->resized_list));
 	tgt_device->commit_total_bytes = src_device->commit_total_bytes;
 	tgt_device->commit_bytes_used = src_device->bytes_used;
-	if (fs_info->sb->s_bdev &&
-		(fs_info->sb->s_bdev == src_device->bdev))
-		fs_info->sb->s_bdev = tgt_device->bdev;
-	if (fs_info->fs_devices->latest_bdev == src_device->bdev)
-		fs_info->fs_devices->latest_bdev = tgt_device->bdev;
+
+	btrfs_assign_next_active_device(fs_info, src_device, tgt_device);
+
 	list_add(&tgt_device->dev_alloc_list, &fs_info->fs_devices->alloc_list);
 	fs_info->fs_devices->rw_devices++;
 
diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index 41bc384f3483..3fb0786060dd 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -1756,10 +1756,49 @@ static int btrfs_check_raid_min_devices(struct btrfs_fs_info *fs_info,
 	return 0;
 }
 
+struct btrfs_device *btrfs_find_next_active_device(struct btrfs_fs_devices *fs_devs,
+					struct btrfs_device *device)
+{
+	struct btrfs_device *next_device;
+
+	list_for_each_entry(next_device, &fs_devs->devices, dev_list) {
+		if (next_device != device &&
+			!next_device->missing && next_device->bdev)
+			return next_device;
+	}
+
+	return NULL;
+}
+
+/*
+ * Helper function to check if the given device is part of s_bdev / latest_bdev
+ * and replace it with the provided or the next active device, in the context
+ * where this function called, there should be always be another device (or
+ * this_dev) which is active.
+ */
+void btrfs_assign_next_active_device(struct btrfs_fs_info *fs_info,
+		struct btrfs_device *device, struct btrfs_device *this_dev)
+{
+	struct btrfs_device *next_device;
+
+	if (this_dev)
+		next_device = this_dev;
+	else
+		next_device = btrfs_find_next_active_device(fs_info->fs_devices,
+								device);
+	ASSERT(next_device);
+
+	if (fs_info->sb->s_bdev &&
+			(fs_info->sb->s_bdev == device->bdev))
+		fs_info->sb->s_bdev = next_device->bdev;
+
+	if (fs_info->fs_devices->latest_bdev == device->bdev)
+		fs_info->fs_devices->latest_bdev = next_device->bdev;
+}
+
 int btrfs_rm_device(struct btrfs_root *root, char *device_path, u64 devid)
 {
 	struct btrfs_device *device;
-	struct btrfs_device *next_device;
 	struct btrfs_fs_devices *cur_devices;
 	u64 num_devices;
 	int ret = 0;
@@ -1846,13 +1885,7 @@ int btrfs_rm_device(struct btrfs_root *root, char *device_path, u64 devid)
 	if (device->missing)
 		device->fs_devices->missing_devices--;
 
-	next_device = list_entry(root->fs_info->fs_devices->devices.next,
-				 struct btrfs_device, dev_list);
-	if (root->fs_info->sb->s_bdev &&
-		(root->fs_info->sb->s_bdev == device->bdev))
-		root->fs_info->sb->s_bdev = next_device->bdev;
-	if (device->bdev == root->fs_info->fs_devices->latest_bdev)
-		root->fs_info->fs_devices->latest_bdev = next_device->bdev;
+	btrfs_assign_next_active_device(root->fs_info, device, NULL);
 
 	if (device->bdev) {
 		device->fs_devices->open_devices--;
@@ -1981,8 +2014,6 @@ void btrfs_rm_dev_replace_free_srcdev(struct btrfs_fs_info *fs_info,
 void btrfs_destroy_dev_replace_tgtdev(struct btrfs_fs_info *fs_info,
 				      struct btrfs_device *tgtdev)
 {
-	struct btrfs_device *next_device;
-
 	mutex_lock(&uuid_mutex);
 	WARN_ON(!tgtdev);
 	mutex_lock(&fs_info->fs_devices->device_list_mutex);
@@ -1995,13 +2026,8 @@ void btrfs_destroy_dev_replace_tgtdev(struct btrfs_fs_info *fs_info,
 	}
 	fs_info->fs_devices->num_devices--;
 
-	next_device = list_entry(fs_info->fs_devices->devices.next,
-				 struct btrfs_device, dev_list);
-	if (fs_info->sb->s_bdev &&
-		(tgtdev->bdev == fs_info->sb->s_bdev))
-		fs_info->sb->s_bdev = next_device->bdev;
-	if (tgtdev->bdev == fs_info->fs_devices->latest_bdev)
-		fs_info->fs_devices->latest_bdev = next_device->bdev;
+	btrfs_assign_next_active_device(fs_info, tgtdev, NULL);
+
 	list_del_rcu(&tgtdev->dev_list);
 
 	call_rcu(&tgtdev->rcu, free_device);
diff --git a/fs/btrfs/volumes.h b/fs/btrfs/volumes.h
index febdb7bc9370..7038017bf93b 100644
--- a/fs/btrfs/volumes.h
+++ b/fs/btrfs/volumes.h
@@ -445,6 +445,8 @@ int btrfs_scan_one_device(const char *path, fmode_t flags, void *holder,
 			  struct btrfs_fs_devices **fs_devices_ret);
 int btrfs_close_devices(struct btrfs_fs_devices *fs_devices);
 void btrfs_close_extra_devices(struct btrfs_fs_devices *fs_devices, int step);
+void btrfs_assign_next_active_device(struct btrfs_fs_info *fs_info,
+		struct btrfs_device *device, struct btrfs_device *this_dev);
 int btrfs_find_device_missing_or_by_path(struct btrfs_root *root,
 					 char *device_path,
 					 struct btrfs_device **device);
-- 
cgit v1.2.3