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Diffstat (limited to 'fs/xfs/xfs_super.c')
-rw-r--r--fs/xfs/xfs_super.c138
1 files changed, 81 insertions, 57 deletions
diff --git a/fs/xfs/xfs_super.c b/fs/xfs/xfs_super.c
index 818510243130..c79eac048456 100644
--- a/fs/xfs/xfs_super.c
+++ b/fs/xfs/xfs_super.c
@@ -377,17 +377,6 @@ disable_dax:
return 0;
}
-static void
-xfs_bdev_mark_dead(
- struct block_device *bdev)
-{
- xfs_force_shutdown(bdev->bd_holder, SHUTDOWN_DEVICE_REMOVED);
-}
-
-static const struct blk_holder_ops xfs_holder_ops = {
- .mark_dead = xfs_bdev_mark_dead,
-};
-
STATIC int
xfs_blkdev_get(
xfs_mount_t *mp,
@@ -396,8 +385,8 @@ xfs_blkdev_get(
{
int error = 0;
- *bdevp = blkdev_get_by_path(name, BLK_OPEN_READ | BLK_OPEN_WRITE, mp,
- &xfs_holder_ops);
+ *bdevp = blkdev_get_by_path(name, BLK_OPEN_READ | BLK_OPEN_WRITE,
+ mp->m_super, &fs_holder_ops);
if (IS_ERR(*bdevp)) {
error = PTR_ERR(*bdevp);
xfs_warn(mp, "Invalid device [%s], error=%d", name, error);
@@ -407,31 +396,45 @@ xfs_blkdev_get(
}
STATIC void
-xfs_blkdev_put(
- struct xfs_mount *mp,
- struct block_device *bdev)
-{
- if (bdev)
- blkdev_put(bdev, mp);
-}
-
-STATIC void
-xfs_close_devices(
+xfs_shutdown_devices(
struct xfs_mount *mp)
{
+ /*
+ * Udev is triggered whenever anyone closes a block device or unmounts
+ * a file systemm on a block device.
+ * The default udev rules invoke blkid to read the fs super and create
+ * symlinks to the bdev under /dev/disk. For this, it uses buffered
+ * reads through the page cache.
+ *
+ * xfs_db also uses buffered reads to examine metadata. There is no
+ * coordination between xfs_db and udev, which means that they can run
+ * concurrently. Note there is no coordination between the kernel and
+ * blkid either.
+ *
+ * On a system with 64k pages, the page cache can cache the superblock
+ * and the root inode (and hence the root directory) with the same 64k
+ * page. If udev spawns blkid after the mkfs and the system is busy
+ * enough that it is still running when xfs_db starts up, they'll both
+ * read from the same page in the pagecache.
+ *
+ * The unmount writes updated inode metadata to disk directly. The XFS
+ * buffer cache does not use the bdev pagecache, so it needs to
+ * invalidate that pagecache on unmount. If the above scenario occurs,
+ * the pagecache no longer reflects what's on disk, xfs_db reads the
+ * stale metadata, and fails to find /a. Most of the time this succeeds
+ * because closing a bdev invalidates the page cache, but when processes
+ * race, everyone loses.
+ */
if (mp->m_logdev_targp && mp->m_logdev_targp != mp->m_ddev_targp) {
- struct block_device *logdev = mp->m_logdev_targp->bt_bdev;
-
- xfs_free_buftarg(mp->m_logdev_targp);
- xfs_blkdev_put(mp, logdev);
+ blkdev_issue_flush(mp->m_logdev_targp->bt_bdev);
+ invalidate_bdev(mp->m_logdev_targp->bt_bdev);
}
if (mp->m_rtdev_targp) {
- struct block_device *rtdev = mp->m_rtdev_targp->bt_bdev;
-
- xfs_free_buftarg(mp->m_rtdev_targp);
- xfs_blkdev_put(mp, rtdev);
+ blkdev_issue_flush(mp->m_rtdev_targp->bt_bdev);
+ invalidate_bdev(mp->m_rtdev_targp->bt_bdev);
}
- xfs_free_buftarg(mp->m_ddev_targp);
+ blkdev_issue_flush(mp->m_ddev_targp->bt_bdev);
+ invalidate_bdev(mp->m_ddev_targp->bt_bdev);
}
/*
@@ -448,17 +451,24 @@ STATIC int
xfs_open_devices(
struct xfs_mount *mp)
{
- struct block_device *ddev = mp->m_super->s_bdev;
+ struct super_block *sb = mp->m_super;
+ struct block_device *ddev = sb->s_bdev;
struct block_device *logdev = NULL, *rtdev = NULL;
int error;
/*
+ * blkdev_put() can't be called under s_umount, see the comment
+ * in get_tree_bdev() for more details
+ */
+ up_write(&sb->s_umount);
+
+ /*
* Open real time and log devices - order is important.
*/
if (mp->m_logname) {
error = xfs_blkdev_get(mp, mp->m_logname, &logdev);
if (error)
- return error;
+ goto out_relock;
}
if (mp->m_rtname) {
@@ -496,7 +506,10 @@ xfs_open_devices(
mp->m_logdev_targp = mp->m_ddev_targp;
}
- return 0;
+ error = 0;
+out_relock:
+ down_write(&sb->s_umount);
+ return error;
out_free_rtdev_targ:
if (mp->m_rtdev_targp)
@@ -504,11 +517,12 @@ xfs_open_devices(
out_free_ddev_targ:
xfs_free_buftarg(mp->m_ddev_targp);
out_close_rtdev:
- xfs_blkdev_put(mp, rtdev);
+ if (rtdev)
+ blkdev_put(rtdev, sb);
out_close_logdev:
if (logdev && logdev != ddev)
- xfs_blkdev_put(mp, logdev);
- return error;
+ blkdev_put(logdev, sb);
+ goto out_relock;
}
/*
@@ -758,6 +772,17 @@ static void
xfs_mount_free(
struct xfs_mount *mp)
{
+ /*
+ * Free the buftargs here because blkdev_put needs to be called outside
+ * of sb->s_umount, which is held around the call to ->put_super.
+ */
+ if (mp->m_logdev_targp && mp->m_logdev_targp != mp->m_ddev_targp)
+ xfs_free_buftarg(mp->m_logdev_targp);
+ if (mp->m_rtdev_targp)
+ xfs_free_buftarg(mp->m_rtdev_targp);
+ if (mp->m_ddev_targp)
+ xfs_free_buftarg(mp->m_ddev_targp);
+
kfree(mp->m_rtname);
kfree(mp->m_logname);
kmem_free(mp);
@@ -1133,10 +1158,6 @@ xfs_fs_put_super(
{
struct xfs_mount *mp = XFS_M(sb);
- /* if ->fill_super failed, we have no mount to tear down */
- if (!sb->s_fs_info)
- return;
-
xfs_notice(mp, "Unmounting Filesystem %pU", &mp->m_sb.sb_uuid);
xfs_filestream_unmount(mp);
xfs_unmountfs(mp);
@@ -1147,10 +1168,7 @@ xfs_fs_put_super(
xfs_inodegc_free_percpu(mp);
xfs_destroy_percpu_counters(mp);
xfs_destroy_mount_workqueues(mp);
- xfs_close_devices(mp);
-
- sb->s_fs_info = NULL;
- xfs_mount_free(mp);
+ xfs_shutdown_devices(mp);
}
static long
@@ -1492,7 +1510,7 @@ xfs_fs_fill_super(
error = xfs_fs_validate_params(mp);
if (error)
- goto out_free_names;
+ return error;
sb_min_blocksize(sb, BBSIZE);
sb->s_xattr = xfs_xattr_handlers;
@@ -1519,11 +1537,11 @@ xfs_fs_fill_super(
error = xfs_open_devices(mp);
if (error)
- goto out_free_names;
+ return error;
error = xfs_init_mount_workqueues(mp);
if (error)
- goto out_close_devices;
+ goto out_shutdown_devices;
error = xfs_init_percpu_counters(mp);
if (error)
@@ -1737,11 +1755,8 @@ xfs_fs_fill_super(
xfs_destroy_percpu_counters(mp);
out_destroy_workqueues:
xfs_destroy_mount_workqueues(mp);
- out_close_devices:
- xfs_close_devices(mp);
- out_free_names:
- sb->s_fs_info = NULL;
- xfs_mount_free(mp);
+ out_shutdown_devices:
+ xfs_shutdown_devices(mp);
return error;
out_unmount:
@@ -1934,7 +1949,8 @@ xfs_fs_reconfigure(
return 0;
}
-static void xfs_fs_free(
+static void
+xfs_fs_free(
struct fs_context *fc)
{
struct xfs_mount *mp = fc->s_fs_info;
@@ -2003,13 +2019,21 @@ static int xfs_init_fs_context(
return 0;
}
+static void
+xfs_kill_sb(
+ struct super_block *sb)
+{
+ kill_block_super(sb);
+ xfs_mount_free(XFS_M(sb));
+}
+
static struct file_system_type xfs_fs_type = {
.owner = THIS_MODULE,
.name = "xfs",
.init_fs_context = xfs_init_fs_context,
.parameters = xfs_fs_parameters,
- .kill_sb = kill_block_super,
- .fs_flags = FS_REQUIRES_DEV | FS_ALLOW_IDMAP,
+ .kill_sb = xfs_kill_sb,
+ .fs_flags = FS_REQUIRES_DEV | FS_ALLOW_IDMAP | FS_MGTIME,
};
MODULE_ALIAS_FS("xfs");