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authorLinus Torvalds2023-08-28 11:04:18 -0700
committerLinus Torvalds2023-08-28 11:04:18 -0700
commit511fb5bafed197ff76d9adf5448de67f1d0558ae (patch)
tree6683ae0e7b62caa9488040d71705768a306f37dd /block/bdev.c
parentde16588a7737b12e63ec646d72b45befb2b1f8f7 (diff)
parentcd4284cfd3e11c7a49e4808f76f53284d47d04dd (diff)
Merge tag 'v6.6-vfs.super' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs
Pull superblock updates from Christian Brauner: "This contains the super rework that was ready for this cycle. The first part changes the order of how we open block devices and allocate superblocks, contains various cleanups, simplifications, and a new mechanism to wait on superblock state changes. This unblocks work to ultimately limit the number of writers to a block device. Jan has already scheduled follow-up work that will be ready for v6.7 and allows us to restrict the number of writers to a given block device. That series builds on this work right here. The second part contains filesystem freezing updates. Overview: The generic superblock changes are rougly organized as follows (ignoring additional minor cleanups): (1) Removal of the bd_super member from struct block_device. This was a very odd back pointer to struct super_block with unclear rules. For all relevant places we have other means to get the same information so just get rid of this. (2) Simplify rules for superblock cleanup. Roughly, everything that is allocated during fs_context initialization and that's stored in fs_context->s_fs_info needs to be cleaned up by the fs_context->free() implementation before the superblock allocation function has been called successfully. After sget_fc() returned fs_context->s_fs_info has been transferred to sb->s_fs_info at which point sb->kill_sb() if fully responsible for cleanup. Adhering to these rules means that cleanup of sb->s_fs_info in fill_super() is to be avoided as it's brittle and inconsistent. Cleanup shouldn't be duplicated between sb->put_super() as sb->put_super() is only called if sb->s_root has been set aka when the filesystem has been successfully born (SB_BORN). That complexity should be avoided. This also means that block devices are to be closed in sb->kill_sb() instead of sb->put_super(). More details in the lower section. (3) Make it possible to lookup or create a superblock before opening block devices There's a subtle dependency on (2) as some filesystems did rely on fill_super() to be called in order to correctly clean up sb->s_fs_info. All these filesystems have been fixed. (4) Switch most filesystem to follow the same logic as the generic mount code now does as outlined in (3). (5) Use the superblock as the holder of the block device. We can now easily go back from block device to owning superblock. (6) Export and extend the generic fs_holder_ops and use them as holder ops everywhere and remove the filesystem specific holder ops. (7) Call from the block layer up into the filesystem layer when the block device is removed, allowing to shut down the filesystem without risk of deadlocks. (8) Get rid of get_super(). We can now easily go back from the block device to owning superblock and can call up from the block layer into the filesystem layer when the device is removed. So no need to wade through all registered superblock to find the owning superblock anymore" Link: https://lore.kernel.org/lkml/20230824-prall-intakt-95dbffdee4a0@brauner/ * tag 'v6.6-vfs.super' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: (47 commits) super: use higher-level helper for {freeze,thaw} super: wait until we passed kill super super: wait for nascent superblocks super: make locking naming consistent super: use locking helpers fs: simplify invalidate_inodes fs: remove get_super block: call into the file system for ioctl BLKFLSBUF block: call into the file system for bdev_mark_dead block: consolidate __invalidate_device and fsync_bdev block: drop the "busy inodes on changed media" log message dasd: also call __invalidate_device when setting the device offline amiflop: don't call fsync_bdev in FDFMTBEG floppy: call disk_force_media_change when changing the format block: simplify the disk_force_media_change interface nbd: call blk_mark_disk_dead in nbd_clear_sock_ioctl xfs use fs_holder_ops for the log and RT devices xfs: drop s_umount over opening the log and RT devices ext4: use fs_holder_ops for the log device ext4: drop s_umount over opening the log device ...
Diffstat (limited to 'block/bdev.c')
-rw-r--r--block/bdev.c69
1 files changed, 32 insertions, 37 deletions
diff --git a/block/bdev.c b/block/bdev.c
index 979e28a46b98..f3b13aa1b7d4 100644
--- a/block/bdev.c
+++ b/block/bdev.c
@@ -206,23 +206,6 @@ int sync_blockdev_range(struct block_device *bdev, loff_t lstart, loff_t lend)
}
EXPORT_SYMBOL(sync_blockdev_range);
-/*
- * Write out and wait upon all dirty data associated with this
- * device. Filesystem data as well as the underlying block
- * device. Takes the superblock lock.
- */
-int fsync_bdev(struct block_device *bdev)
-{
- struct super_block *sb = get_super(bdev);
- if (sb) {
- int res = sync_filesystem(sb);
- drop_super(sb);
- return res;
- }
- return sync_blockdev(bdev);
-}
-EXPORT_SYMBOL(fsync_bdev);
-
/**
* freeze_bdev - lock a filesystem and force it into a consistent state
* @bdev: blockdevice to lock
@@ -248,9 +231,9 @@ int freeze_bdev(struct block_device *bdev)
if (!sb)
goto sync;
if (sb->s_op->freeze_super)
- error = sb->s_op->freeze_super(sb);
+ error = sb->s_op->freeze_super(sb, FREEZE_HOLDER_USERSPACE);
else
- error = freeze_super(sb);
+ error = freeze_super(sb, FREEZE_HOLDER_USERSPACE);
deactivate_super(sb);
if (error) {
@@ -291,9 +274,9 @@ int thaw_bdev(struct block_device *bdev)
goto out;
if (sb->s_op->thaw_super)
- error = sb->s_op->thaw_super(sb);
+ error = sb->s_op->thaw_super(sb, FREEZE_HOLDER_USERSPACE);
else
- error = thaw_super(sb);
+ error = thaw_super(sb, FREEZE_HOLDER_USERSPACE);
if (error)
bdev->bd_fsfreeze_count++;
else
@@ -960,26 +943,38 @@ out_path_put:
}
EXPORT_SYMBOL(lookup_bdev);
-int __invalidate_device(struct block_device *bdev, bool kill_dirty)
+/**
+ * bdev_mark_dead - mark a block device as dead
+ * @bdev: block device to operate on
+ * @surprise: indicate a surprise removal
+ *
+ * Tell the file system that this devices or media is dead. If @surprise is set
+ * to %true the device or media is already gone, if not we are preparing for an
+ * orderly removal.
+ *
+ * This calls into the file system, which then typicall syncs out all dirty data
+ * and writes back inodes and then invalidates any cached data in the inodes on
+ * the file system. In addition we also invalidate the block device mapping.
+ */
+void bdev_mark_dead(struct block_device *bdev, bool surprise)
{
- struct super_block *sb = get_super(bdev);
- int res = 0;
+ mutex_lock(&bdev->bd_holder_lock);
+ if (bdev->bd_holder_ops && bdev->bd_holder_ops->mark_dead)
+ bdev->bd_holder_ops->mark_dead(bdev, surprise);
+ else
+ sync_blockdev(bdev);
+ mutex_unlock(&bdev->bd_holder_lock);
- if (sb) {
- /*
- * no need to lock the super, get_super holds the
- * read mutex so the filesystem cannot go away
- * under us (->put_super runs with the write lock
- * hold).
- */
- shrink_dcache_sb(sb);
- res = invalidate_inodes(sb, kill_dirty);
- drop_super(sb);
- }
invalidate_bdev(bdev);
- return res;
}
-EXPORT_SYMBOL(__invalidate_device);
+#ifdef CONFIG_DASD_MODULE
+/*
+ * Drivers should not use this directly, but the DASD driver has historically
+ * had a shutdown to offline mode that doesn't actually remove the gendisk
+ * that otherwise looks a lot like a safe device removal.
+ */
+EXPORT_SYMBOL_GPL(bdev_mark_dead);
+#endif
void sync_bdevs(bool wait)
{