Btrfs stable patches for 4.5.x

Btrfs stable patches for 4.5.x

[David Sterba]

Hi,

please queue the following patches to 4.5 stable. There are fixes for user
visible bugs, improved error handling and stability fixes, all picked from
current 4.7 changes.

The patches do not apply cleanly on top of 4.5.6 so I'll send them as reply to
this mail, now with the stable changelog notices in place.

I have tested the patches on top of 4.5. Some patches may apply to older stable
branches but haven't been tested nor reviewed them in that respect.

Subjects:
        btrfs: bugfix: handle FS_IOC32_{GETFLAGS,SETFLAGS,GETVERSION} in btrfs_ioctl
        Btrfs: do not create empty block group if we have allocated data
        btrfs: allow balancing to dup with multi-device
        btrfs: fix mixed block count of available space
        btrfs: avoid overflowing f_bfree
        btrfs: fix lock dep warning, move scratch dev out of device_list_mutex and uuid_mutex
        btrfs: add read-only check to sysfs handler of features
        btrfs: add check to sysfs handler of label
        Btrfs: fix divide error upon chunk's stripe_len
        Btrfs: remove BUG_ON()'s in btrfs_map_block
        btrfs: fix lock dep warning move scratch super outside of chunk_mutex
        btrfs: add write protection to SET_FEATURES ioctl
        btrfs: fix int32 overflow in shrink_delalloc().
        Btrfs: fix fspath error deallocation
        btrfs: fix memory leak during RAID 5/6 device replacement
        btrfs: pass the right error code to the btrfs_std_error
        Btrfs: fix for incorrect directory entries after fsync log replay
        Btrfs: fix empty symlink after creating symlink and fsync parent dir
        Btrfs: fix unexpected return value of fiemap
        btrfs: scrub: Set bbio to NULL before calling btrfs_map_block
        btrfs: make state preallocation more speculative in __set_extent_bit
Commits:
        4c63c2454eff996c5e27991221106eb511f7db38
        cf25ce518e8ef9d59b292e51193bed2b023a32da
        88be159c905a2b4f6d59afa352bef410afb6af02
        ae02d1bd070767e109f4a6f1bb1f466e9698a355
        41b34accb265e3a20211a7a8ef3625678f1c6ec7
        779bf3fefa835cb52a07457c8acac6f2f66f2493
        ee6111386a1b304f8bf589d36810d53e3b27ee20
        66ac9fe7bacf9fa76c472efc7a7aaa590c7bce6a
        3d8da67817606380fdadfa483d4dba5c3a5446c6
        e042d1ec4417981dfe9331e47b76f17929bc2ffe
        48b3b9d401ec86899a52003b37331190a35a81a6
        7ab19625a911f7568ec85302e3aa7a64186006c8
        8eb0dfdbda3f56bf7d248ed87fcc383df114ecbb
        72928f2476d08c79f132b4f44a17c9a011dd98e3
        4673272f43ae790ab9ec04e38a7542f82bb8f020
        ad8403df054c9b5dc3175a26c6179571b9cafa4e
        657ed1aa4898c8304500e0d13f240d5a67e8be5f
        3f9749f6e9edcf8ec569fb542efc3be35e06e84a
        2d324f59f343967a03eeb2690f0ff178304d0687
        f1fee6534dcfbf468a159789aa202db2bce8c200
        059f791c6bbaba72dc3c1bd6e2657aacc8552849

[PATCH 01/21] btrfs: bugfix: handle FS_IOC32_{GETFLAGS,SETFLAGS,GETVERSION} in btrfs_ioctl

[David Sterba]

From: Luke Dashjr <luke@dashjr.org>

commit 4c63c2454eff996c5e27991221106eb511f7db38 upstream.

32-bit ioctl uses these rather than the regular FS_IOC_* versions. They can
be handled in btrfs using the same code. Without this, 32-bit {ch,ls}attr
fail.

Signed-off-by: Luke Dashjr <luke-jr+git@utopios.org>
Cc: stable@vger.kernel.org
Reviewed-by: Josef Bacik <jbacik@fb.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
---
 fs/btrfs/ctree.h |  1 +
 fs/btrfs/file.c  |  2 +-
 fs/btrfs/inode.c |  2 +-
 fs/btrfs/ioctl.c | 21 +++++++++++++++++++++
 4 files changed, 24 insertions(+), 2 deletions(-)

diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index 6661ad8b4088..7c9a9c026e21 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -4089,6 +4089,7 @@ void btrfs_test_inode_set_ops(struct inode *inode);
 
 /* ioctl.c */
 long btrfs_ioctl(struct file *file, unsigned int cmd, unsigned long arg);
+long btrfs_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg);
 void btrfs_update_iflags(struct inode *inode);
 void btrfs_inherit_iflags(struct inode *inode, struct inode *dir);
 int btrfs_is_empty_uuid(u8 *uuid);
diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c
index 5d956b869e03..187fa7b9bae7 100644
--- a/fs/btrfs/file.c
+++ b/fs/btrfs/file.c
@@ -2931,7 +2931,7 @@ const struct file_operations btrfs_file_operations = {
 	.fallocate	= btrfs_fallocate,
 	.unlocked_ioctl	= btrfs_ioctl,
 #ifdef CONFIG_COMPAT
-	.compat_ioctl	= btrfs_ioctl,
+	.compat_ioctl	= btrfs_compat_ioctl,
 #endif
 	.copy_file_range = btrfs_copy_file_range,
 	.clone_file_range = btrfs_clone_file_range,
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index f407e487c687..0db33cb4a2ac 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -10088,7 +10088,7 @@ static const struct file_operations btrfs_dir_file_operations = {
 	.iterate	= btrfs_real_readdir,
 	.unlocked_ioctl	= btrfs_ioctl,
 #ifdef CONFIG_COMPAT
-	.compat_ioctl	= btrfs_ioctl,
+	.compat_ioctl	= btrfs_compat_ioctl,
 #endif
 	.release        = btrfs_release_file,
 	.fsync		= btrfs_sync_file,
diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index e3791f268489..ea21e588a839 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -5555,3 +5555,24 @@ long btrfs_ioctl(struct file *file, unsigned int
 
 	return -ENOTTY;
 }
+
+#ifdef CONFIG_COMPAT
+long btrfs_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
+{
+	switch (cmd) {
+	case FS_IOC32_GETFLAGS:
+		cmd = FS_IOC_GETFLAGS;
+		break;
+	case FS_IOC32_SETFLAGS:
+		cmd = FS_IOC_SETFLAGS;
+		break;
+	case FS_IOC32_GETVERSION:
+		cmd = FS_IOC_GETVERSION;
+		break;
+	default:
+		return -ENOIOCTLCMD;
+	}
+
+	return btrfs_ioctl(file, cmd, (unsigned long) compat_ptr(arg));
+}
+#endif
-- 
2.7.1

[PATCH 02/21] Btrfs: do not create empty block group if we have allocated data

[David Sterba]

From: Liu Bo <bo.li.liu@oracle.com>

commit cf25ce518e8ef9d59b292e51193bed2b023a32da upstream.

Now we force to create empty block group to keep data profile alive,
however, in the below example, we eventually get an empty block group
while we're trying to get more space for other types (metadata/system),

- Before,
block group "A": size=2G, used=1.2G
block group "B": size=2G, used=512M

- After "btrfs balance start -dusage=50 mount_point",
block group "A": size=2G, used=(1.2+0.5)G
block group "C": size=2G, used=0

Since there is no data in block group C, it won't be deleted
automatically and we have to get the unused 2G until the next mount.

Balance itself just moves data and doesn't remove data, so it's safe
to not create such a empty block group if we already have data
 allocated in other block groups.

Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
---
 fs/btrfs/volumes.c | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index 366b335946fa..adb5f697a963 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -3401,6 +3401,7 @@ static int __btrfs_balance(struct btrfs_fs_info *fs_info)
 	u32 count_meta = 0;
 	u32 count_sys = 0;
 	int chunk_reserved = 0;
+	u64 bytes_used = 0;
 
 	/* step one make some room on all the devices */
 	devices = &fs_info->fs_devices->devices;
@@ -3539,7 +3540,13 @@ static int __btrfs_balance(struct btrfs_fs_info *fs_info)
 			goto loop;
 		}
 
-		if ((chunk_type & BTRFS_BLOCK_GROUP_DATA) && !chunk_reserved) {
+		ASSERT(fs_info->data_sinfo);
+		spin_lock(&fs_info->data_sinfo->lock);
+		bytes_used = fs_info->data_sinfo->bytes_used;
+		spin_unlock(&fs_info->data_sinfo->lock);
+
+		if ((chunk_type & BTRFS_BLOCK_GROUP_DATA) &&
+		    !chunk_reserved && !bytes_used) {
 			trans = btrfs_start_transaction(chunk_root, 0);
 			if (IS_ERR(trans)) {
 				mutex_unlock(&fs_info->delete_unused_bgs_mutex);
-- 
2.7.1

[PATCH 03/21] btrfs: allow balancing to dup with multi-device

[David Sterba]

From: "Austin S. Hemmelgarn" <ahferroin7@gmail.com>

commit 88be159c905a2b4f6d59afa352bef410afb6af02 upstream.

Currently, we don't allow the user to try and rebalance to a dup profile
on a multi-device filesystem.  In most cases, this is a perfectly sensible
restriction as raid1 uses the same amount of space and provides better
protection.

However, when reshaping a multi-device filesystem down to a single device
filesystem, this requires the user to convert metadata and system chunks
to single profile before deleting devices, and then convert again to dup,
which leaves a period of time where metadata integrity is reduced.

This patch removes the single-device-only restriction from converting to
dup profile to remove this potential data integrity reduction.

Signed-off-by: Austin S. Hemmelgarn <ahferroin7@gmail.com>
Signed-off-by: David Sterba <dsterba@suse.com>
---
 fs/btrfs/volumes.c | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index adb5f697a963..89c2aabaea2d 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -3699,10 +3699,8 @@ int btrfs_balance(struct btrfs_balance_control *bctl,
 		num_devices--;
 	}
 	btrfs_dev_replace_unlock(&fs_info->dev_replace);
-	allowed = BTRFS_AVAIL_ALLOC_BIT_SINGLE;
-	if (num_devices == 1)
-		allowed |= BTRFS_BLOCK_GROUP_DUP;
-	else if (num_devices > 1)
+	allowed = BTRFS_AVAIL_ALLOC_BIT_SINGLE | BTRFS_BLOCK_GROUP_DUP;
+	if (num_devices > 1)
 		allowed |= (BTRFS_BLOCK_GROUP_RAID0 | BTRFS_BLOCK_GROUP_RAID1);
 	if (num_devices > 2)
 		allowed |= BTRFS_BLOCK_GROUP_RAID5;
-- 
2.7.1

[PATCH 04/21] btrfs: fix mixed block count of available space

[David Sterba]

From: Luis de Bethencourt <luisbg@osg.samsung.com>

commit ae02d1bd070767e109f4a6f1bb1f466e9698a355 upstream.

Metadata for mixed block is already accounted in total data and should not
be counted as part of the free metadata space.

Signed-off-by: Luis de Bethencourt <luisbg@osg.samsung.com>
Link: https://bugzilla.kernel.org/show_bug.cgi?id=114281
Signed-off-by: David Sterba <dsterba@suse.com>
---
 fs/btrfs/super.c | 16 +++++++++++++---
 1 file changed, 13 insertions(+), 3 deletions(-)

diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c
index d41e09fe8e38..4e6f842b5ad2 100644
--- a/fs/btrfs/super.c
+++ b/fs/btrfs/super.c
@@ -2024,6 +2024,7 @@ static int btrfs_statfs(struct dentry *dentry, struct kstatfs *buf)
 	struct btrfs_block_rsv *block_rsv = &fs_info->global_block_rsv;
 	int ret;
 	u64 thresh = 0;
+	int mixed = 0;
 
 	/*
 	 * holding chunk_muext to avoid allocating new chunks, holding
@@ -2049,8 +2050,17 @@ static int btrfs_statfs(struct dentry *dentry, struct kstatfs *buf)
 				}
 			}
 		}
-		if (found->flags & BTRFS_BLOCK_GROUP_METADATA)
-			total_free_meta += found->disk_total - found->disk_used;
+
+		/*
+		 * Metadata in mixed block goup profiles are accounted in data
+		 */
+		if (!mixed && found->flags & BTRFS_BLOCK_GROUP_METADATA) {
+			if (found->flags & BTRFS_BLOCK_GROUP_DATA)
+				mixed = 1;
+			else
+				total_free_meta += found->disk_total -
+					found->disk_used;
+		}
 
 		total_used += found->disk_used;
 	}
@@ -2088,7 +2098,7 @@ static int btrfs_statfs(struct dentry *dentry, struct kstatfs *buf)
 	 */
 	thresh = 4 * 1024 * 1024;
 
-	if (total_free_meta - thresh < block_rsv->size)
+	if (!mixed && total_free_meta - thresh < block_rsv->size)
 		buf->f_bavail = 0;
 
 	buf->f_type = BTRFS_SUPER_MAGIC;
-- 
2.7.1

[PATCH 05/21] btrfs: avoid overflowing f_bfree

[David Sterba]

From: Luis de Bethencourt <luisbg@osg.samsung.com>

commit 41b34accb265e3a20211a7a8ef3625678f1c6ec7 upstream.

Since mixed block groups accounting isn't byte-accurate and f_bree is an
unsigned integer, it could overflow. Avoid this.

Signed-off-by: Luis de Bethencourt <luisbg@osg.samsung.com>
Suggested-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
---
 fs/btrfs/super.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c
index 4e6f842b5ad2..468e988d8110 100644
--- a/fs/btrfs/super.c
+++ b/fs/btrfs/super.c
@@ -2073,7 +2073,11 @@ static int btrfs_statfs(struct dentry *dentry, struct kstatfs *buf)
 
 	/* Account global block reserve as used, it's in logical size already */
 	spin_lock(&block_rsv->lock);
-	buf->f_bfree -= block_rsv->size >> bits;
+	/* Mixed block groups accounting is not byte-accurate, avoid overflow */
+	if (buf->f_bfree >= block_rsv->size >> bits)
+		buf->f_bfree -= block_rsv->size >> bits;
+	else
+		buf->f_bfree = 0;
 	spin_unlock(&block_rsv->lock);
 
 	buf->f_bavail = div_u64(total_free_data, factor);
-- 
2.7.1

[PATCH 06/21] btrfs: fix lock dep warning, move scratch dev out of device_list_mutex and uuid_mutex

[David Sterba]

From: Anand Jain <anand.jain@oracle.com>

commit 779bf3fefa835cb52a07457c8acac6f2f66f2493 upstream.

When the replace target fails, the target device will be taken
out of fs device list, scratch + update_dev_time and freed. However
we could do the scratch  + update_dev_time and free part after the
device has been taken out of device list, so that we don't have to
hold the device_list_mutex and uuid_mutex locks.

Reported issue:

[ 5375.718845] ======================================================
[ 5375.718846] [ INFO: possible circular locking dependency detected ]
[ 5375.718849] 4.4.5-scst31x-debug-11+ #40 Not tainted
[ 5375.718849] -------------------------------------------------------
[ 5375.718851] btrfs-health/4662 is trying to acquire lock:
[ 5375.718861]  (sb_writers){.+.+.+}, at: [<ffffffff812214f7>] __sb_start_write+0xb7/0xf0
[ 5375.718862]
[ 5375.718862] but task is already holding lock:
[ 5375.718907]  (&fs_devs->device_list_mutex){+.+.+.}, at: [<ffffffffa028263c>] btrfs_destroy_dev_replace_tgtdev+0x3c/0x150 [btrfs]
[ 5375.718907]
[ 5375.718907] which lock already depends on the new lock.
[ 5375.718907]
[ 5375.718908]
[ 5375.718908] the existing dependency chain (in reverse order) is:
[ 5375.718911]
[ 5375.718911] -> #3 (&fs_devs->device_list_mutex){+.+.+.}:
[ 5375.718917]        [<ffffffff810da4be>] lock_acquire+0xce/0x1e0
[ 5375.718921]        [<ffffffff81633949>] mutex_lock_nested+0x69/0x3c0
[ 5375.718940]        [<ffffffffa0219bf6>] btrfs_show_devname+0x36/0x210 [btrfs]
[ 5375.718945]        [<ffffffff81267079>] show_vfsmnt+0x49/0x150
[ 5375.718948]        [<ffffffff81240b07>] m_show+0x17/0x20
[ 5375.718951]        [<ffffffff81246868>] seq_read+0x2d8/0x3b0
[ 5375.718955]        [<ffffffff8121df28>] __vfs_read+0x28/0xd0
[ 5375.718959]        [<ffffffff8121e806>] vfs_read+0x86/0x130
[ 5375.718962]        [<ffffffff8121f4c9>] SyS_read+0x49/0xa0
[ 5375.718966]        [<ffffffff81637976>] entry_SYSCALL_64_fastpath+0x16/0x7a
[ 5375.718968]
[ 5375.718968] -> #2 (namespace_sem){+++++.}:
[ 5375.718971]        [<ffffffff810da4be>] lock_acquire+0xce/0x1e0
[ 5375.718974]        [<ffffffff81635199>] down_write+0x49/0x80
[ 5375.718977]        [<ffffffff81243593>] lock_mount+0x43/0x1c0
[ 5375.718979]        [<ffffffff81243c13>] do_add_mount+0x23/0xd0
[ 5375.718982]        [<ffffffff81244afb>] do_mount+0x27b/0xe30
[ 5375.718985]        [<ffffffff812459dc>] SyS_mount+0x8c/0xd0
[ 5375.718988]        [<ffffffff81637976>] entry_SYSCALL_64_fastpath+0x16/0x7a
[ 5375.718991]
[ 5375.718991] -> #1 (&sb->s_type->i_mutex_key#5){+.+.+.}:
[ 5375.718994]        [<ffffffff810da4be>] lock_acquire+0xce/0x1e0
[ 5375.718996]        [<ffffffff81633949>] mutex_lock_nested+0x69/0x3c0
[ 5375.719001]        [<ffffffff8122d608>] path_openat+0x468/0x1360
[ 5375.719004]        [<ffffffff8122f86e>] do_filp_open+0x7e/0xe0
[ 5375.719007]        [<ffffffff8121da7b>] do_sys_open+0x12b/0x210
[ 5375.719010]        [<ffffffff8121db7e>] SyS_open+0x1e/0x20
[ 5375.719013]        [<ffffffff81637976>] entry_SYSCALL_64_fastpath+0x16/0x7a
[ 5375.719015]
[ 5375.719015] -> #0 (sb_writers){.+.+.+}:
[ 5375.719018]        [<ffffffff810d97ca>] __lock_acquire+0x17ba/0x1ae0
[ 5375.719021]        [<ffffffff810da4be>] lock_acquire+0xce/0x1e0
[ 5375.719026]        [<ffffffff810d3bef>] percpu_down_read+0x4f/0xa0
[ 5375.719028]        [<ffffffff812214f7>] __sb_start_write+0xb7/0xf0
[ 5375.719031]        [<ffffffff81242eb4>] mnt_want_write+0x24/0x50
[ 5375.719035]        [<ffffffff8122ded2>] path_openat+0xd32/0x1360
[ 5375.719037]        [<ffffffff8122f86e>] do_filp_open+0x7e/0xe0
[ 5375.719040]        [<ffffffff8121d8a4>] file_open_name+0xe4/0x130
[ 5375.719043]        [<ffffffff8121d923>] filp_open+0x33/0x60
[ 5375.719073]        [<ffffffffa02776a6>] update_dev_time+0x16/0x40 [btrfs]
[ 5375.719099]        [<ffffffffa02825be>] btrfs_scratch_superblocks+0x4e/0x90 [btrfs]
[ 5375.719123]        [<ffffffffa0282665>] btrfs_destroy_dev_replace_tgtdev+0x65/0x150 [btrfs]
[ 5375.719150]        [<ffffffffa02c6c80>] btrfs_dev_replace_finishing+0x6b0/0x990 [btrfs]
[ 5375.719175]        [<ffffffffa02c729e>] btrfs_dev_replace_start+0x33e/0x540 [btrfs]
[ 5375.719199]        [<ffffffffa02c7f58>] btrfs_auto_replace_start+0xf8/0x140 [btrfs]
[ 5375.719222]        [<ffffffffa02464e6>] health_kthread+0x246/0x490 [btrfs]
[ 5375.719225]        [<ffffffff810a70df>] kthread+0xef/0x110
[ 5375.719229]        [<ffffffff81637d2f>] ret_from_fork+0x3f/0x70
[ 5375.719230]
[ 5375.719230] other info that might help us debug this:
[ 5375.719230]
[ 5375.719233] Chain exists of:
[ 5375.719233]   sb_writers --> namespace_sem --> &fs_devs->device_list_mutex
[ 5375.719233]
[ 5375.719234]  Possible unsafe locking scenario:
[ 5375.719234]
[ 5375.719234]        CPU0                    CPU1
[ 5375.719235]        ----                    ----
[ 5375.719236]   lock(&fs_devs->device_list_mutex);
[ 5375.719238]                                lock(namespace_sem);
[ 5375.719239]                                lock(&fs_devs->device_list_mutex);
[ 5375.719241]   lock(sb_writers);
[ 5375.719241]
[ 5375.719241]  *** DEADLOCK ***
[ 5375.719241]
[ 5375.719243] 4 locks held by btrfs-health/4662:
[ 5375.719266]  #0:  (&fs_info->health_mutex){+.+.+.}, at: [<ffffffffa0246303>] health_kthread+0x63/0x490 [btrfs]
[ 5375.719293]  #1:  (&fs_info->dev_replace.lock_finishing_cancel_unmount){+.+.+.}, at: [<ffffffffa02c6611>] btrfs_dev_replace_finishing+0x41/0x990 [btrfs]
[ 5375.719319]  #2:  (uuid_mutex){+.+.+.}, at: [<ffffffffa0282620>] btrfs_destroy_dev_replace_tgtdev+0x20/0x150 [btrfs]
[ 5375.719343]  #3:  (&fs_devs->device_list_mutex){+.+.+.}, at: [<ffffffffa028263c>] btrfs_destroy_dev_replace_tgtdev+0x3c/0x150 [btrfs]
[ 5375.719343]
[ 5375.719343] stack backtrace:
[ 5375.719347] CPU: 2 PID: 4662 Comm: btrfs-health Not tainted 4.4.5-scst31x-debug-11+ #40
[ 5375.719348] Hardware name: Supermicro SYS-6018R-WTRT/X10DRW-iT, BIOS 1.0c 01/07/2015
[ 5375.719352]  0000000000000000 ffff880856f73880 ffffffff813529e3 ffffffff826182a0
[ 5375.719354]  ffffffff8260c090 ffff880856f738c0 ffffffff810d667c ffff880856f73930
[ 5375.719357]  ffff880861f32b40 ffff880861f32b68 0000000000000003 0000000000000004
[ 5375.719357] Call Trace:
[ 5375.719363]  [<ffffffff813529e3>] dump_stack+0x85/0xc2
[ 5375.719366]  [<ffffffff810d667c>] print_circular_bug+0x1ec/0x260
[ 5375.719369]  [<ffffffff810d97ca>] __lock_acquire+0x17ba/0x1ae0
[ 5375.719373]  [<ffffffff810f606d>] ? debug_lockdep_rcu_enabled+0x1d/0x20
[ 5375.719376]  [<ffffffff810da4be>] lock_acquire+0xce/0x1e0
[ 5375.719378]  [<ffffffff812214f7>] ? __sb_start_write+0xb7/0xf0
[ 5375.719383]  [<ffffffff810d3bef>] percpu_down_read+0x4f/0xa0
[ 5375.719385]  [<ffffffff812214f7>] ? __sb_start_write+0xb7/0xf0
[ 5375.719387]  [<ffffffff812214f7>] __sb_start_write+0xb7/0xf0
[ 5375.719389]  [<ffffffff81242eb4>] mnt_want_write+0x24/0x50
[ 5375.719393]  [<ffffffff8122ded2>] path_openat+0xd32/0x1360
[ 5375.719415]  [<ffffffffa02462a0>] ? btrfs_congested_fn+0x180/0x180 [btrfs]
[ 5375.719418]  [<ffffffff810f606d>] ? debug_lockdep_rcu_enabled+0x1d/0x20
[ 5375.719420]  [<ffffffff8122f86e>] do_filp_open+0x7e/0xe0
[ 5375.719423]  [<ffffffff810f615d>] ? rcu_read_lock_sched_held+0x6d/0x80
[ 5375.719426]  [<ffffffff81201a9b>] ? kmem_cache_alloc+0x26b/0x5d0
[ 5375.719430]  [<ffffffff8122e7d4>] ? getname_kernel+0x34/0x120
[ 5375.719433]  [<ffffffff8121d8a4>] file_open_name+0xe4/0x130
[ 5375.719436]  [<ffffffff8121d923>] filp_open+0x33/0x60
[ 5375.719462]  [<ffffffffa02776a6>] update_dev_time+0x16/0x40 [btrfs]
[ 5375.719485]  [<ffffffffa02825be>] btrfs_scratch_superblocks+0x4e/0x90 [btrfs]
[ 5375.719506]  [<ffffffffa0282665>] btrfs_destroy_dev_replace_tgtdev+0x65/0x150 [btrfs]
[ 5375.719530]  [<ffffffffa02c6c80>] btrfs_dev_replace_finishing+0x6b0/0x990 [btrfs]
[ 5375.719554]  [<ffffffffa02c6b23>] ? btrfs_dev_replace_finishing+0x553/0x990 [btrfs]
[ 5375.719576]  [<ffffffffa02c729e>] btrfs_dev_replace_start+0x33e/0x540 [btrfs]
[ 5375.719598]  [<ffffffffa02c7f58>] btrfs_auto_replace_start+0xf8/0x140 [btrfs]
[ 5375.719621]  [<ffffffffa02464e6>] health_kthread+0x246/0x490 [btrfs]
[ 5375.719641]  [<ffffffffa02463d8>] ? health_kthread+0x138/0x490 [btrfs]
[ 5375.719661]  [<ffffffffa02462a0>] ? btrfs_congested_fn+0x180/0x180 [btrfs]
[ 5375.719663]  [<ffffffff810a70df>] kthread+0xef/0x110
[ 5375.719666]  [<ffffffff810a6ff0>] ? kthread_create_on_node+0x200/0x200
[ 5375.719669]  [<ffffffff81637d2f>] ret_from_fork+0x3f/0x70
[ 5375.719672]  [<ffffffff810a6ff0>] ? kthread_create_on_node+0x200/0x200
[ 5375.719697] ------------[ cut here ]------------

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/volumes.c | 17 ++++++++++++-----
 1 file changed, 12 insertions(+), 5 deletions(-)

diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index 89c2aabaea2d..27a4f2e0856d 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -2023,10 +2023,9 @@ void btrfs_destroy_dev_replace_tgtdev(struct btrfs_fs_info *fs_info,
 
 	btrfs_sysfs_rm_device_link(fs_info->fs_devices, tgtdev);
 
-	if (tgtdev->bdev) {
-		btrfs_scratch_superblocks(tgtdev->bdev, tgtdev->name->str);
+	if (tgtdev->bdev)
 		fs_info->fs_devices->open_devices--;
-	}
+
 	fs_info->fs_devices->num_devices--;
 
 	next_device = list_entry(fs_info->fs_devices->devices.next,
@@ -2037,10 +2036,18 @@ void btrfs_destroy_dev_replace_tgtdev(struct btrfs_fs_info *fs_info,
 		fs_info->fs_devices->latest_bdev = next_device->bdev;
 	list_del_rcu(&tgtdev->dev_list);
 
-	call_rcu(&tgtdev->rcu, free_device);
-
 	mutex_unlock(&fs_info->fs_devices->device_list_mutex);
 	mutex_unlock(&uuid_mutex);
+
+	/*
+	 * The update_dev_time() with in btrfs_scratch_superblocks()
+	 * may lead to a call to btrfs_show_devname() which will try
+	 * to hold device_list_mutex. And here this device
+	 * is already out of device list, so we don't have to hold
+	 * the device_list_mutex lock.
+	 */
+	btrfs_scratch_superblocks(tgtdev->bdev, tgtdev->name->str);
+	call_rcu(&tgtdev->rcu, free_device);
 }
 
 static int btrfs_find_device_by_path(struct btrfs_root *root, char *device_path,
-- 
2.7.1

[PATCH 07/21] btrfs: add read-only check to sysfs handler of features

[David Sterba]

From: David Sterba <dsterba@suse.cz>

commit ee6111386a1b304f8bf589d36810d53e3b27ee20 upstream.

We don't want to trigger the change on a read-only filesystem, similar
to what the label handler does.

Signed-off-by: David Sterba <dsterba@suse.cz>
---
 fs/btrfs/sysfs.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/fs/btrfs/sysfs.c b/fs/btrfs/sysfs.c
index 539e7b5e3f86..6a6bb600b1ff 100644
--- a/fs/btrfs/sysfs.c
+++ b/fs/btrfs/sysfs.c
@@ -120,6 +120,9 @@ static ssize_t btrfs_feature_attr_store(struct kobject *kobj,
 	if (!fs_info)
 		return -EPERM;
 
+	if (fs_info->sb->s_flags & MS_RDONLY)
+		return -EROFS;
+
 	ret = kstrtoul(skip_spaces(buf), 0, &val);
 	if (ret)
 		return ret;
-- 
2.7.1

[PATCH 08/21] btrfs: add check to sysfs handler of label

[David Sterba]

commit 66ac9fe7bacf9fa76c472efc7a7aaa590c7bce6a upstream.

Add a sanity check for the fs_info as we will dereference it, similar to
what the 'store features' handler does.

Signed-off-by: David Sterba <dsterba@suse.com>
---
 fs/btrfs/sysfs.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/fs/btrfs/sysfs.c b/fs/btrfs/sysfs.c
index 6a6bb600b1ff..3d14618ce54b 100644
--- a/fs/btrfs/sysfs.c
+++ b/fs/btrfs/sysfs.c
@@ -377,6 +377,9 @@ static ssize_t btrfs_label_store(struct kobject *kobj,
 	struct btrfs_fs_info *fs_info = to_fs_info(kobj);
 	size_t p_len;
 
+	if (!fs_info)
+		return -EPERM;
+
 	if (fs_info->sb->s_flags & MS_RDONLY)
 		return -EROFS;
 
-- 
2.7.1

[PATCH 09/21] Btrfs: fix divide error upon chunk's stripe_len

[David Sterba]

From: Liu Bo <bo.li.liu@oracle.com>

commit 3d8da67817606380fdadfa483d4dba5c3a5446c6 upstream.

The struct 'map_lookup' uses type int for @stripe_len, while
btrfs_chunk_stripe_len() can return a u64 value, and it may end up with
@stripe_len being undefined value and it can lead to 'divide error' in
 __btrfs_map_block().

This changes 'map_lookup' to use type u64 for stripe_len, also right now
we only use BTRFS_STRIPE_LEN for stripe_len, so this adds a valid checker for
BTRFS_STRIPE_LEN.

Reported-by: Vegard Nossum <vegard.nossum@oracle.com>
Reported-by: Quentin Casasnovas <quentin.casasnovas@oracle.com>
Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
[ folded division fix to scrub_raid56_parity ]
Signed-off-by: David Sterba <dsterba@suse.com>
---
 fs/btrfs/scrub.c   | 2 +-
 fs/btrfs/volumes.c | 2 +-
 fs/btrfs/volumes.h | 2 +-
 3 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/fs/btrfs/scrub.c b/fs/btrfs/scrub.c
index 92bf5ee732fb..160ac3e23270 100644
--- a/fs/btrfs/scrub.c
+++ b/fs/btrfs/scrub.c
@@ -2858,7 +2858,7 @@ static noinline_for_stack int scrub_raid56_parity(struct scrub_ctx *sctx,
 	int extent_mirror_num;
 	int stop_loop = 0;
 
-	nsectors = map->stripe_len / root->sectorsize;
+	nsectors = div_u64(map->stripe_len, root->sectorsize);
 	bitmap_len = scrub_calc_parity_bitmap_len(nsectors);
 	sparity = kzalloc(sizeof(struct scrub_parity) + 2 * bitmap_len,
 			  GFP_NOFS);
diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index 27a4f2e0856d..f4442fb6b8d4 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -6249,7 +6249,7 @@ static int read_one_chunk(struct btrfs_root *root, struct btrfs_key *key,
 			"invalid chunk length %llu", length);
 		return -EIO;
 	}
-	if (!is_power_of_2(stripe_len)) {
+	if (!is_power_of_2(stripe_len) || stripe_len != BTRFS_STRIPE_LEN) {
 		btrfs_err(root->fs_info, "invalid chunk stripe length: %llu",
 			  stripe_len);
 		return -EIO;
diff --git a/fs/btrfs/volumes.h b/fs/btrfs/volumes.h
index 1939ebde63df..7507be74f7da 100644
--- a/fs/btrfs/volumes.h
+++ b/fs/btrfs/volumes.h
@@ -347,7 +347,7 @@ struct map_lookup {
 	u64 type;
 	int io_align;
 	int io_width;
-	int stripe_len;
+	u64 stripe_len;
 	int sector_size;
 	int num_stripes;
 	int sub_stripes;
-- 
2.7.1

[PATCH 10/21] Btrfs: remove BUG_ON()'s in btrfs_map_block

[David Sterba]

From: Josef Bacik <jbacik@fb.com>

commit e042d1ec4417981dfe9331e47b76f17929bc2ffe upstream.

btrfs_map_block can go horribly wrong in the face of fs corruption, lets agree
to not be assholes and panic at any possible chance things are all fucked up.

Signed-off-by: Josef Bacik <jbacik@fb.com>
[ removed type casts ]
Signed-off-by: David Sterba <dsterba@suse.com>
---
 fs/btrfs/volumes.c | 18 ++++++++++++++++--
 1 file changed, 16 insertions(+), 2 deletions(-)

diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index f4442fb6b8d4..839c2e9e89ae 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -5289,7 +5289,15 @@ static int __btrfs_map_block(struct btrfs_fs_info *fs_info, int rw,
 	stripe_nr = div64_u64(stripe_nr, stripe_len);
 
 	stripe_offset = stripe_nr * stripe_len;
-	BUG_ON(offset < stripe_offset);
+	if (offset < stripe_offset) {
+		btrfs_crit(fs_info, "stripe math has gone wrong, "
+			   "stripe_offset=%llu, offset=%llu, start=%llu, "
+			   "logical=%llu, stripe_len=%llu",
+			   stripe_offset, offset, em->start, logical,
+			   stripe_len);
+		free_extent_map(em);
+		return -EINVAL;
+	}
 
 	/* stripe_offset is the offset of this block in its stripe*/
 	stripe_offset = offset - stripe_offset;
@@ -5528,7 +5536,13 @@ static int __btrfs_map_block(struct btrfs_fs_info *fs_info, int rw,
 				&stripe_index);
 		mirror_num = stripe_index + 1;
 	}
-	BUG_ON(stripe_index >= map->num_stripes);
+	if (stripe_index >= map->num_stripes) {
+		btrfs_crit(fs_info, "stripe index math went horribly wrong, "
+			   "got stripe_index=%u, num_stripes=%u",
+			   stripe_index, map->num_stripes);
+		ret = -EINVAL;
+		goto out;
+	}
 
 	num_alloc_stripes = num_stripes;
 	if (dev_replace_is_ongoing) {
-- 
2.7.1

[PATCH 11/21] btrfs: fix lock dep warning move scratch super outside of chunk_mutex

[David Sterba]

From: Anand Jain <anand.jain@oracle.com>

commit 48b3b9d401ec86899a52003b37331190a35a81a6 upstream.

Move scratch super outside of the chunk lock to avoid below
lockdep warning. The better place to scratch super is in
the function btrfs_rm_dev_replace_free_srcdev() just before
free_device, which is outside of the chunk lock as well.

To reproduce:
  (fresh boot)
  mkfs.btrfs -f -draid5 -mraid5 /dev/sdc /dev/sdd /dev/sde
  mount /dev/sdc /btrfs
  dd if=/dev/zero of=/btrfs/tf1 bs=4096 count=100
  (get devmgt from https://github.com/asj/devmgt.git)
  devmgt detach /dev/sde
  dd if=/dev/zero of=/btrfs/tf1 bs=4096 count=100
  sync
  btrfs replace start -Brf 3 /dev/sdf /btrfs <--
  devmgt attach host7

======================================================
[ INFO: possible circular locking dependency detected ]
4.6.0-rc2asj+ #1 Not tainted
---------------------------------------------------

btrfs/2174 is trying to acquire lock:
(sb_writers){.+.+.+}, at:
[<ffffffff812449b4>] __sb_start_write+0xb4/0xf0

but task is already holding lock:
(&fs_info->chunk_mutex){+.+.+.}, at:
[<ffffffffa05c5f55>] btrfs_dev_replace_finishing+0x145/0x980 [btrfs]

which lock already depends on the new lock.

Chain exists of:
sb_writers --> &fs_devs->device_list_mutex --> &fs_info->chunk_mutex
Possible unsafe locking scenario:
CPU0				CPU1
----				----
lock(&fs_info->chunk_mutex);
				lock(&fs_devs->device_list_mutex);
				lock(&fs_info->chunk_mutex);
lock(sb_writers);

*** DEADLOCK ***

-> #0 (sb_writers){.+.+.+}:
[<ffffffff810e6415>] __lock_acquire+0x1bc5/0x1ee0
[<ffffffff810e707e>] lock_acquire+0xbe/0x210
[<ffffffff810df49a>] percpu_down_read+0x4a/0xa0
[<ffffffff812449b4>] __sb_start_write+0xb4/0xf0
[<ffffffff81265534>] mnt_want_write+0x24/0x50
[<ffffffff812508a2>] path_openat+0x952/0x1190
[<ffffffff81252451>] do_filp_open+0x91/0x100
[<ffffffff8123f5cc>] file_open_name+0xfc/0x140
[<ffffffff8123f643>] filp_open+0x33/0x60
[<ffffffffa0572bb6>] update_dev_time+0x16/0x40 [btrfs]
[<ffffffffa057f60d>] btrfs_scratch_superblocks+0x5d/0xb0 [btrfs]
[<ffffffffa057f70e>] btrfs_rm_dev_replace_remove_srcdev+0xae/0xd0 [btrfs]
[<ffffffffa05c62c5>] btrfs_dev_replace_finishing+0x4b5/0x980 [btrfs]
[<ffffffffa05c6ae8>] btrfs_dev_replace_start+0x358/0x530 [btrfs]

Signed-off-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
---
 fs/btrfs/volumes.c | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index 839c2e9e89ae..542c04388ba5 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -1971,11 +1971,8 @@ void btrfs_rm_dev_replace_remove_srcdev(struct btrfs_fs_info *fs_info,
 	if (srcdev->missing)
 		fs_devices->missing_devices--;
 
-	if (srcdev->writeable) {
+	if (srcdev->writeable)
 		fs_devices->rw_devices--;
-		/* zero out the old super if it is writable */
-		btrfs_scratch_superblocks(srcdev->bdev, srcdev->name->str);
-	}
 
 	if (srcdev->bdev)
 		fs_devices->open_devices--;
@@ -1986,6 +1983,10 @@ void btrfs_rm_dev_replace_free_srcdev(struct btrfs_fs_info *fs_info,
 {
 	struct btrfs_fs_devices *fs_devices = srcdev->fs_devices;
 
+	if (srcdev->writeable) {
+		/* zero out the old super if it is writable */
+		btrfs_scratch_superblocks(srcdev->bdev, srcdev->name->str);
+	}
 	call_rcu(&srcdev->rcu, free_device);
 
 	/*
-- 
2.7.1

[PATCH 12/21] btrfs: add write protection to SET_FEATURES ioctl

[David Sterba]

From: David Sterba <dsterba@suse.cz>

commit 7ab19625a911f7568ec85302e3aa7a64186006c8 upstream.

Perform the want_write check if we get far enough to do any writes.

Signed-off-by: David Sterba <dsterba@suse.com>
---
 fs/btrfs/ioctl.c | 16 +++++++++++++---
 1 file changed, 13 insertions(+), 3 deletions(-)

diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index ea21e588a839..14e291422ab1 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -5397,9 +5397,15 @@ static int btrfs_ioctl_set_features(struct file *file, void __user *arg)
 	if (ret)
 		return ret;
 
+	ret = mnt_want_write_file(file);
+	if (ret)
+		return ret;
+
 	trans = btrfs_start_transaction(root, 0);
-	if (IS_ERR(trans))
-		return PTR_ERR(trans);
+	if (IS_ERR(trans)) {
+		ret = PTR_ERR(trans);
+		goto out_drop_write;
+	}
 
 	spin_lock(&root->fs_info->super_lock);
 	newflags = btrfs_super_compat_flags(super_block);
@@ -5418,7 +5424,11 @@ static int btrfs_ioctl_set_features(struct file *file, void __user *arg)
 	btrfs_set_super_incompat_flags(super_block, newflags);
 	spin_unlock(&root->fs_info->super_lock);
 
-	return btrfs_commit_transaction(trans, root);
+	ret = btrfs_commit_transaction(trans, root);
+out_drop_write:
+	mnt_drop_write_file(file);
+
+	return ret;
 }
 
 long btrfs_ioctl(struct file *file, unsigned int
-- 
2.7.1

[PATCH 13/21] btrfs: fix int32 overflow in shrink_delalloc().

[David Sterba]

From: Adam Borowski <kilobyte@angband.pl>

commit 8eb0dfdbda3f56bf7d248ed87fcc383df114ecbb upstream.

UBSAN: Undefined behaviour in fs/btrfs/extent-tree.c:4623:21
signed integer overflow:
10808 * 262144 cannot be represented in type 'int [8]'

If 8192<=items<16384, we request a writeback of an insane number of pages
which is benign (everything will be written).  But if items>=16384, the
space reservation won't be enough.

Signed-off-by: Adam Borowski <kilobyte@angband.pl>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
---
 fs/btrfs/extent-tree.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index e2287c7c10be..95e57320dd75 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -4620,7 +4620,7 @@ static void shrink_delalloc(struct btrfs_root *root, u64 to_reclaim, u64 orig,
 
 	/* Calc the number of the pages we need flush for space reservation */
 	items = calc_reclaim_items_nr(root, to_reclaim);
-	to_reclaim = items * EXTENT_SIZE_PER_ITEM;
+	to_reclaim = (u64)items * EXTENT_SIZE_PER_ITEM;
 
 	trans = (struct btrfs_trans_handle *)current->journal_info;
 	block_rsv = &root->fs_info->delalloc_block_rsv;
-- 
2.7.1

[PATCH 14/21] Btrfs: fix fspath error deallocation

[David Sterba]

From: Vincent Stehlé <vincent.stehle@intel.com>

commit 72928f2476d08c79f132b4f44a17c9a011dd98e3 upstream.

Make sure to deallocate fspath with vfree() in case of error in
init_ipath().

fspath is allocated with vmalloc() in init_data_container() since
commit 425d17a290c0 ("Btrfs: use larger limit for translation of logical to
inode").

Signed-off-by: Vincent Stehlé <vincent.stehle@intel.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
---
 fs/btrfs/backref.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/btrfs/backref.c b/fs/btrfs/backref.c
index f6dac40f87ff..6442a31c2119 100644
--- a/fs/btrfs/backref.c
+++ b/fs/btrfs/backref.c
@@ -1995,7 +1995,7 @@ struct inode_fs_paths *init_ipath(s32 total_bytes, struct btrfs_root *fs_root,
 
 	ifp = kmalloc(sizeof(*ifp), GFP_NOFS);
 	if (!ifp) {
-		kfree(fspath);
+		vfree(fspath);
 		return ERR_PTR(-ENOMEM);
 	}
 
-- 
2.7.1

[PATCH 15/21] btrfs: fix memory leak during RAID 5/6 device replacement

[David Sterba]

From: Scott Talbert <scott.talbert@hgst.com>

commit 4673272f43ae790ab9ec04e38a7542f82bb8f020 upstream.

A 'struct bio' is allocated in scrub_missing_raid56_pages(), but it was never
freed anywhere.

Signed-off-by: Scott Talbert <scott.talbert@hgst.com>
Signed-off-by: David Sterba <dsterba@suse.com>
---
 fs/btrfs/scrub.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/fs/btrfs/scrub.c b/fs/btrfs/scrub.c
index 160ac3e23270..ee046f6fffe0 100644
--- a/fs/btrfs/scrub.c
+++ b/fs/btrfs/scrub.c
@@ -2125,6 +2125,8 @@ static void scrub_missing_raid56_end_io(struct bio *bio)
 	if (bio->bi_error)
 		sblock->no_io_error_seen = 0;
 
+	bio_put(bio);
+
 	btrfs_queue_work(fs_info->scrub_workers, &sblock->work);
 }
 
-- 
2.7.1

[PATCH 16/21] btrfs: pass the right error code to the btrfs_std_error

[David Sterba]

From: Anand Jain <anand.jain@oracle.com>

commit ad8403df054c9b5dc3175a26c6179571b9cafa4e upstream.

Also drop the newline from the message.

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

diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index 14e291422ab1..4b035cc7ed54 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -4849,8 +4849,8 @@ static long btrfs_ioctl_qgroup_assign(struct file *file, void __user *arg)
 	/* update qgroup status and info */
 	err = btrfs_run_qgroups(trans, root->fs_info);
 	if (err < 0)
-		btrfs_std_error(root->fs_info, ret,
-			    "failed to update qgroup status and info\n");
+		btrfs_std_error(root->fs_info, err,
+			    "failed to update qgroup status and info");
 	err = btrfs_end_transaction(trans, root);
 	if (err && !ret)
 		ret = err;
-- 
2.7.1

[PATCH 17/21] Btrfs: fix for incorrect directory entries after fsync log replay

[David Sterba]

From: Filipe Manana <fdmanana@suse.com>

commit 657ed1aa4898c8304500e0d13f240d5a67e8be5f upstream.

If we move a directory to a new parent and later log that parent and don't
explicitly log the old parent, when we replay the log we can end up with
entries for the moved directory in both the old and new parent directories.
Besides being ilegal to have directories with multiple hard links in linux,
it also resulted in the leaving the inode item with a link count of 1.
A similar issue also happens if we move a regular file - after the log tree
is replayed the file has a link in both the old and new parent directories,
when it should be only at the new directory.

Sample reproducer:

  $ mkfs.btrfs -f /dev/sdc
  $ mount /dev/sdc /mnt
  $ mkdir /mnt/x
  $ mkdir /mnt/y
  $ touch /mnt/x/foo
  $ mkdir /mnt/y/z
  $ sync
  $ ln /mnt/x/foo /mnt/x/bar
  $ mv /mnt/y/z /mnt/x/z
  < power fail >
  $ mount /dev/sdc /mnt
  $ ls -1Ri /mnt
  /mnt:
  257 x
  258 y

  /mnt/x:
  259 bar
  259 foo
  260 z

  /mnt/x/z:

  /mnt/y:
  260 z

  /mnt/y/z:

  $ umount /dev/sdc
  $ btrfs check /dev/sdc
  Checking filesystem on /dev/sdc
  UUID: a67e2c4a-a4b4-4fdc-b015-9d9af1e344be
  checking extents
  checking free space cache
  checking fs roots
  root 5 inode 260 errors 2000, link count wrong
        unresolved ref dir 257 index 4 namelen 1 name z filetype 2 errors 0
        unresolved ref dir 258 index 2 namelen 1 name z filetype 2 errors 0
  (...)

Attempting to remove the directory becomes impossible:

  $ mount /dev/sdc /mnt
  $ rmdir /mnt/y/z
  $ ls -lh /mnt/y
  ls: cannot access /mnt/y/z: No such file or directory
  total 0
  d????????? ? ? ? ?            ? z
  $ rmdir /mnt/x/z
  rmdir: failed to remove ‘/mnt/x/z’: Stale file handle
  $ ls -lh /mnt/x
  ls: cannot access /mnt/x/z: Stale file handle
  total 0
  -rw-r--r-- 2 root root 0 Apr  6 18:06 bar
  -rw-r--r-- 2 root root 0 Apr  6 18:06 foo
  d????????? ? ?    ?    ?            ? z

So make sure that on rename we set the last_unlink_trans value for our
inode, even if it's a directory, to the value of the current transaction's
ID and that if the new parent directory is logged that we fallback to a
transaction commit.

A test case for fstests is being submitted as well.

Signed-off-by: Filipe Manana <fdmanana@suse.com>
---
 fs/btrfs/tree-log.c | 13 ++++++++-----
 1 file changed, 8 insertions(+), 5 deletions(-)

diff --git a/fs/btrfs/tree-log.c b/fs/btrfs/tree-log.c
index 58ae0a2ce65c..23df70e7f884 100644
--- a/fs/btrfs/tree-log.c
+++ b/fs/btrfs/tree-log.c
@@ -5277,11 +5277,16 @@ static int btrfs_log_all_parents(struct btrfs_trans_handle *trans,
 			if (IS_ERR(dir_inode))
 				continue;
 
+			if (ctx)
+				ctx->log_new_dentries = false;
 			ret = btrfs_log_inode(trans, root, dir_inode,
 					      LOG_INODE_ALL, 0, LLONG_MAX, ctx);
 			if (!ret &&
 			    btrfs_must_commit_transaction(trans, dir_inode))
 				ret = 1;
+			if (!ret && ctx && ctx->log_new_dentries)
+				ret = log_new_dir_dentries(trans, root,
+							   dir_inode, ctx);
 			iput(dir_inode);
 			if (ret)
 				goto out;
@@ -5651,11 +5656,9 @@ void btrfs_record_unlink_dir(struct btrfs_trans_handle *trans,
 	 * into the file.  When the file is logged we check it and
 	 * don't log the parents if the file is fully on disk.
 	 */
-	if (S_ISREG(inode->i_mode)) {
-		mutex_lock(&BTRFS_I(inode)->log_mutex);
-		BTRFS_I(inode)->last_unlink_trans = trans->transid;
-		mutex_unlock(&BTRFS_I(inode)->log_mutex);
-	}
+	mutex_lock(&BTRFS_I(inode)->log_mutex);
+	BTRFS_I(inode)->last_unlink_trans = trans->transid;
+	mutex_unlock(&BTRFS_I(inode)->log_mutex);
 
 	/*
 	 * if this directory was already logged any new
-- 
2.7.1

[PATCH 18/21] Btrfs: fix empty symlink after creating symlink and fsync parent dir

[David Sterba]

From: Filipe Manana <fdmanana@suse.com>

commit 3f9749f6e9edcf8ec569fb542efc3be35e06e84a upstream.

If we create a symlink, fsync its parent directory, crash/power fail and
mount the filesystem, we end up with an empty symlink, which not only is
useless it's also not allowed in linux (the man page symlink(2) is well
explicit about that).  So we just need to make sure to fully log an inode
if it's a symlink, to ensure its inline extent gets logged, ensuring the
same behaviour as ext3, ext4, xfs, reiserfs, f2fs, nilfs2, etc.

Example reproducer:

  $ mkfs.btrfs -f /dev/sdb
  $ mount /dev/sdb /mnt
  $ mkdir /mnt/testdir
  $ sync
  $ ln -s /mnt/foo /mnt/testdir/bar
  $ xfs_io -c fsync /mnt/testdir
  <power fail>
  $ mount /dev/sdb /mnt
  $ readlink /mnt/testdir/bar
  <empty string>

A test case for fstests follows soon.

Signed-off-by: Filipe Manana <fdmanana@suse.com>
---
 fs/btrfs/tree-log.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/btrfs/tree-log.c b/fs/btrfs/tree-log.c
index 23df70e7f884..a2cd42107945 100644
--- a/fs/btrfs/tree-log.c
+++ b/fs/btrfs/tree-log.c
@@ -5157,7 +5157,7 @@ static int log_new_dir_dentries(struct btrfs_trans_handle *trans,
 			}
 
 			ctx->log_new_dentries = false;
-			if (type == BTRFS_FT_DIR)
+			if (type == BTRFS_FT_DIR || type == BTRFS_FT_SYMLINK)
 				log_mode = LOG_INODE_ALL;
 			btrfs_release_path(path);
 			ret = btrfs_log_inode(trans, root, di_inode,
-- 
2.7.1

[PATCH 19/21] Btrfs: fix unexpected return value of fiemap

[David Sterba]

From: Liu Bo <bo.li.liu@oracle.com>

commit 2d324f59f343967a03eeb2690f0ff178304d0687 upstream.

btrfs's fiemap is supposed to return 0 on success and return < 0 on
error. however, ret becomes 1 after looking up the last file extent:

  btrfs_lookup_file_extent ->
    btrfs_search_slot(..., ins_len=0, cow=0)

and if the offset is beyond EOF, we'll get 'path' pointed to the place
of potentail insertion, and ret == 1.

This may confuse applications using ioctl(FIEL_IOC_FIEMAP).

Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
---
 fs/btrfs/extent_io.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
index 392592dc7010..57fccc420697 100644
--- a/fs/btrfs/extent_io.c
+++ b/fs/btrfs/extent_io.c
@@ -4385,8 +4385,12 @@ int extent_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
 	if (ret < 0) {
 		btrfs_free_path(path);
 		return ret;
+	} else {
+		WARN_ON(!ret);
+		if (ret == 1)
+			ret = 0;
 	}
-	WARN_ON(!ret);
+
 	path->slots[0]--;
 	btrfs_item_key_to_cpu(path->nodes[0], &found_key, path->slots[0]);
 	found_type = found_key.type;
-- 
2.7.1

[PATCH 20/21] btrfs: scrub: Set bbio to NULL before calling btrfs_map_block

[David Sterba]

From: Zhao Lei <zhaolei@cn.fujitsu.com>

commit f1fee6534dcfbf468a159789aa202db2bce8c200 upstream.

We usually call btrfs_put_bbio() when btrfs_map_block() failed,
btrfs_put_bbio() works right whether bbio is a valid value, or NULL.

But there is a exception, in some case, btrfs_map_block() will return
fail without touching *bbio(keeping its original value), and if bbio
was not initialized yet, invalid memory accessing will happened.

Above case is in scrub_missing_raid56_pages(), and similar case in
scrub_raid56_parity().

Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com>
Signed-off-by: David Sterba <dsterba@suse.com>
---
 fs/btrfs/scrub.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/fs/btrfs/scrub.c b/fs/btrfs/scrub.c
index ee046f6fffe0..2b7986e9df03 100644
--- a/fs/btrfs/scrub.c
+++ b/fs/btrfs/scrub.c
@@ -2179,7 +2179,7 @@ static void scrub_missing_raid56_pages(struct scrub_block *sblock)
 	struct btrfs_fs_info *fs_info = sctx->dev_root->fs_info;
 	u64 length = sblock->page_count * PAGE_SIZE;
 	u64 logical = sblock->pagev[0]->logical;
-	struct btrfs_bio *bbio;
+	struct btrfs_bio *bbio = NULL;
 	struct bio *bio;
 	struct btrfs_raid_bio *rbio;
 	int ret;
@@ -2980,6 +2980,7 @@ static noinline_for_stack int scrub_raid56_parity(struct scrub_ctx *sctx,
 						       extent_len);
 
 			mapped_length = extent_len;
+			bbio = NULL;
 			ret = btrfs_map_block(fs_info, READ, extent_logical,
 					      &mapped_length, &bbio, 0);
 			if (!ret) {
-- 
2.7.1

[PATCH 21/21] btrfs: make state preallocation more speculative in __set_extent_bit

[David Sterba]

commit 059f791c6bbaba72dc3c1bd6e2657aacc8552849 upstream.

Similar to __clear_extent_bit, do not fail if the state preallocation
fails as we might not need it. One less BUG_ON.

Signed-off-by: David Sterba <dsterba@suse.com>
---
 fs/btrfs/extent_io.c | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
index 57fccc420697..b5ff48d6a0c5 100644
--- a/fs/btrfs/extent_io.c
+++ b/fs/btrfs/extent_io.c
@@ -875,8 +875,14 @@ __set_extent_bit(struct extent_io_tree *tree, u64 start, u64 end,
 	bits |= EXTENT_FIRST_DELALLOC;
 again:
 	if (!prealloc && gfpflags_allow_blocking(mask)) {
+		/*
+		 * Don't care for allocation failure here because we might end
+		 * up not needing the pre-allocated extent state at all, which
+		 * is the case if we only have in the tree extent states that
+		 * cover our input range and don't cover too any other range.
+		 * If we end up needing a new extent state we allocate it later.
+		 */
 		prealloc = alloc_extent_state(mask);
-		BUG_ON(!prealloc);
 	}
 
 	spin_lock(&tree->lock);
-- 
2.7.1

Re: Btrfs stable patches for 4.5.x

[Greg KH]

On Fri, Jun 03, 2016 at 05:40:06PM +0200, David Sterba wrote:
> Hi,
> 
> please queue the following patches to 4.5 stable. There are fixes for user
> visible bugs, improved error handling and stability fixes, all picked from
> current 4.7 changes.
> 
> The patches do not apply cleanly on top of 4.5.6 so I'll send them as reply to
> this mail, now with the stable changelog notices in place.
> 
> I have tested the patches on top of 4.5. Some patches may apply to older stable
> branches but haven't been tested nor reviewed them in that respect.

Thanks for these, all now applied, just in time for the last 4.5-stable
kernel to be released :)

greg k-h