The patch titled
Subject: fs: explicitly unregister per-superblock BDIs
has been added to the -mm tree. Its filename is
fs-explicitly-unregister-per-superblock-bdis.patch
This patch should soon appear at
https://ozlabs.org/~akpm/mmots/broken-out/fs-explicitly-unregister-per-superblock-bdis.patch
and later at
https://ozlabs.org/~akpm/mmotm/broken-out/fs-explicitly-unregister-per-superblock-bdis.patch
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------------------------------------------------------
From: Christoph Hellwig <hch@xxxxxx>
Subject: fs: explicitly unregister per-superblock BDIs
Add a new SB_I_ flag to mark superblocks that have an ephemeral bdi
associated with them, and unregister it when the superblock is shut down.
Link: https://lkml.kernel.org/r/20211021124441.668816-4-hch@xxxxxx
Signed-off-by: Christoph Hellwig <hch@xxxxxx>
Cc: Jan Kara <jack@xxxxxxx>
Cc: Miquel Raynal <miquel.raynal@xxxxxxxxxxx>
Cc: Richard Weinberger <richard@xxxxxx>
Cc: Vignesh Raghavendra <vigneshr@xxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
fs/super.c | 3 +++
include/linux/fs.h | 1 +
2 files changed, 4 insertions(+)
--- a/fs/super.c~fs-explicitly-unregister-per-superblock-bdis
+++ a/fs/super.c
@@ -476,6 +476,8 @@ void generic_shutdown_super(struct super
spin_unlock(&sb_lock);
up_write(&sb->s_umount);
if (sb->s_bdi != &noop_backing_dev_info) {
+ if (sb->s_iflags & SB_I_PERSB_BDI)
+ bdi_unregister(sb->s_bdi);
bdi_put(sb->s_bdi);
sb->s_bdi = &noop_backing_dev_info;
}
@@ -1562,6 +1564,7 @@ int super_setup_bdi_name(struct super_bl
}
WARN_ON(sb->s_bdi != &noop_backing_dev_info);
sb->s_bdi = bdi;
+ sb->s_iflags |= SB_I_PERSB_BDI;
return 0;
}
--- a/include/linux/fs.h~fs-explicitly-unregister-per-superblock-bdis
+++ a/include/linux/fs.h
@@ -1443,6 +1443,7 @@ extern int send_sigurg(struct fown_struc
#define SB_I_UNTRUSTED_MOUNTER 0x00000040
#define SB_I_SKIP_SYNC 0x00000100 /* Skip superblock at global sync */
+#define SB_I_PERSB_BDI 0x00000200 /* has a per-sb bdi */
/* Possible states of 'frozen' field */
enum {
_
Patches currently in -mm which might be from hch@xxxxxx are
mm-dont-include-linux-daxh-in-linux-mempolicyh.patch
mm-export-bdi_unregister.patch
mtd-call-bdi_unregister-explicitly.patch
fs-explicitly-unregister-per-superblock-bdis.patch
mm-dont-automatically-unregister-bdis.patch
mm-simplify-bdi-refcounting.patch
mm-unexport-folio_memcg_unlock.patch
mm-unexport-unlock_page_memcg.patch
