--- /dev/null
+From 50d281fc434cb8e2497f5e70a309ccca6b1a09f0 Mon Sep 17 00:00:00 2001
+From: Anand Jain <anand.jain@oracle.com>
+Date: Thu, 23 Mar 2023 15:56:48 +0800
+Subject: btrfs: scan device in non-exclusive mode
+
+From: Anand Jain <anand.jain@oracle.com>
+
+commit 50d281fc434cb8e2497f5e70a309ccca6b1a09f0 upstream.
+
+This fixes mkfs/mount/check failures due to race with systemd-udevd
+scan.
+
+During the device scan initiated by systemd-udevd, other user space
+EXCL operations such as mkfs, mount, or check may get blocked and result
+in a "Device or resource busy" error. This is because the device
+scan process opens the device with the EXCL flag in the kernel.
+
+Two reports were received:
+
+ - btrfs/179 test case, where the fsck command failed with the -EBUSY
+ error
+
+ - LTP pwritev03 test case, where mkfs.vfs failed with
+ the -EBUSY error, when mkfs.vfs tried to overwrite old btrfs filesystem
+ on the device.
+
+In both cases, fsck and mkfs (respectively) were racing with a
+systemd-udevd device scan, and systemd-udevd won, resulting in the
+-EBUSY error for fsck and mkfs.
+
+Reproducing the problem has been difficult because there is a very
+small window during which these userspace threads can race to
+acquire the exclusive device open. Even on the system where the problem
+was observed, the problem occurrences were anywhere between 10 to 400
+iterations and chances of reproducing decreases with debug printk()s.
+
+However, an exclusive device open is unnecessary for the scan process,
+as there are no write operations on the device during scan. Furthermore,
+during the mount process, the superblock is re-read in the below
+function call chain:
+
+ btrfs_mount_root
+ btrfs_open_devices
+ open_fs_devices
+ btrfs_open_one_device
+ btrfs_get_bdev_and_sb
+
+So, to fix this issue, removes the FMODE_EXCL flag from the scan
+operation, and add a comment.
+
+The case where mkfs may still write to the device and a scan is running,
+the btrfs signature is not written at that time so scan will not
+recognize such device.
+
+Reported-by: Sherry Yang <sherry.yang@oracle.com>
+Reported-by: kernel test robot <oliver.sang@intel.com>
+Link: https://lore.kernel.org/oe-lkp/202303170839.fdf23068-oliver.sang@intel.com
+CC: stable@vger.kernel.org # 5.4+
+Signed-off-by: Anand Jain <anand.jain@oracle.com>
+Reviewed-by: David Sterba <dsterba@suse.com>
+Signed-off-by: David Sterba <dsterba@suse.com>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+---
+ fs/btrfs/volumes.c | 11 ++++++++++-
+ 1 file changed, 10 insertions(+), 1 deletion(-)
+
+--- a/fs/btrfs/volumes.c
++++ b/fs/btrfs/volumes.c
+@@ -1411,8 +1411,17 @@ struct btrfs_device *btrfs_scan_one_devi
+ * later supers, using BTRFS_SUPER_MIRROR_MAX instead
+ */
+ bytenr = btrfs_sb_offset(0);
+- flags |= FMODE_EXCL;
+
++ /*
++ * Avoid using flag |= FMODE_EXCL here, as the systemd-udev may
++ * initiate the device scan which may race with the user's mount
++ * or mkfs command, resulting in failure.
++ * Since the device scan is solely for reading purposes, there is
++ * no need for FMODE_EXCL. Additionally, the devices are read again
++ * during the mount process. It is ok to get some inconsistent
++ * values temporarily, as the device paths of the fsid are the only
++ * required information for assembling the volume.
++ */
+ bdev = blkdev_get_by_path(path, flags, holder);
+ if (IS_ERR(bdev))
+ return ERR_CAST(bdev);
--- /dev/null
+From 89aba4c26fae4e459f755a18912845c348ee48f3 Mon Sep 17 00:00:00 2001
+From: Heiko Carstens <hca@linux.ibm.com>
+Date: Thu, 23 Mar 2023 13:09:16 +0100
+Subject: s390/uaccess: add missing earlyclobber annotations to __clear_user()
+
+From: Heiko Carstens <hca@linux.ibm.com>
+
+commit 89aba4c26fae4e459f755a18912845c348ee48f3 upstream.
+
+Add missing earlyclobber annotation to size, to, and tmp2 operands of the
+__clear_user() inline assembly since they are modified or written to before
+the last usage of all input operands. This can lead to incorrect register
+allocation for the inline assembly.
+
+Fixes: 6c2a9e6df604 ("[S390] Use alternative user-copy operations for new hardware.")
+Reported-by: Mark Rutland <mark.rutland@arm.com>
+Link: https://lore.kernel.org/all/20230321122514.1743889-3-mark.rutland@arm.com/
+Cc: stable@vger.kernel.org
+Reviewed-by: Gerald Schaefer <gerald.schaefer@linux.ibm.com>
+Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
+Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+---
+ arch/s390/lib/uaccess.c | 2 +-
+ 1 file changed, 1 insertion(+), 1 deletion(-)
+
+--- a/arch/s390/lib/uaccess.c
++++ b/arch/s390/lib/uaccess.c
+@@ -339,7 +339,7 @@ static inline unsigned long clear_user_m
+ "4: slgr %0,%0\n"
+ "5:\n"
+ EX_TABLE(0b,2b) EX_TABLE(3b,5b)
+- : "+a" (size), "+a" (to), "+a" (tmp1), "=a" (tmp2)
++ : "+&a" (size), "+&a" (to), "+a" (tmp1), "=&a" (tmp2)
+ : "a" (empty_zero_page), "d" (reg0) : "cc", "memory");
+ return size;
+ }
--- /dev/null
+From 88b170088ad2c3e27086fe35769aa49f8a512564 Mon Sep 17 00:00:00 2001
+From: Damien Le Moal <damien.lemoal@opensource.wdc.com>
+Date: Mon, 20 Mar 2023 22:49:15 +0900
+Subject: zonefs: Fix error message in zonefs_file_dio_append()
+
+From: Damien Le Moal <damien.lemoal@opensource.wdc.com>
+
+commit 88b170088ad2c3e27086fe35769aa49f8a512564 upstream.
+
+Since the expected write location in a sequential file is always at the
+end of the file (append write), when an invalid write append location is
+detected in zonefs_file_dio_append(), print the invalid written location
+instead of the expected write location.
+
+Fixes: a608da3bd730 ("zonefs: Detect append writes at invalid locations")
+Cc: stable@vger.kernel.org
+Signed-off-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>
+Reviewed-by: Christoph Hellwig <hch@lst.de>
+Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
+Reviewed-by: Himanshu Madhani <himanshu.madhani@oracle.com>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+---
+ fs/zonefs/super.c | 2 +-
+ 1 file changed, 1 insertion(+), 1 deletion(-)
+
+--- a/fs/zonefs/super.c
++++ b/fs/zonefs/super.c
+@@ -789,7 +789,7 @@ static ssize_t zonefs_file_dio_append(st
+ if (bio->bi_iter.bi_sector != wpsector) {
+ zonefs_warn(inode->i_sb,
+ "Corrupted write pointer %llu for zone at %llu\n",
+- wpsector, zi->i_zsector);
++ bio->bi_iter.bi_sector, zi->i_zsector);
+ ret = -EIO;
+ }
+ }
projects / thirdparty / kernel / stable-queue.git / commitdiff
