diff mbox series

[v2,4/4] btrfs: introduce new "rescue=ignoresuperflags" mount option

Message ID 6e7b92ebb72f7e6e213f9cb601a3e5d246fdb594.1718338860.git.wqu@suse.com (mailing list archive)
State New, archived
Headers show
Series btrfs: rescue= mount options enhancement to support interrupted csum conversion | expand

Commit Message

Qu Wenruo June 14, 2024, 4:22 a.m. UTC 
This new mount option would allow the kernel to skip the super flags
check, it's mostly to allow the kernel to do a rescue mount of an
interrupted checksum conversion.

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
---
 fs/btrfs/disk-io.c | 16 ++++++++++++----
 fs/btrfs/fs.h      |  1 +
 fs/btrfs/super.c   | 13 ++++++++++++-
 fs/btrfs/sysfs.c   |  1 +
 4 files changed, 26 insertions(+), 5 deletions(-)

Comments

Geert Uytterhoeven July 10, 2024, 8:21 a.m. UTC | #1 
Hi Qu,

On Fri, 14 Jun 2024, Qu Wenruo wrote:
> This new mount option would allow the kernel to skip the super flags
> check, it's mostly to allow the kernel to do a rescue mount of an
> interrupted checksum conversion.
>
> Reviewed-by: Josef Bacik <josef@toxicpanda.com>
> Signed-off-by: Qu Wenruo <wqu@suse.com>

Thanks for your patch, which is now commit cbc2bc70b8c22974 ("btrfs:
introduce new "rescue=ignoresuperflags" mount option") in next-20240709.

> --- a/fs/btrfs/fs.h
> +++ b/fs/btrfs/fs.h
> @@ -226,6 +226,7 @@ enum {
> 	BTRFS_MOUNT_NODISCARD			= (1UL << 29),
> 	BTRFS_MOUNT_NOSPACECACHE		= (1UL << 30),
> 	BTRFS_MOUNT_IGNOREMETACSUMS		= (1UL << 31),
> +	BTRFS_MOUNT_IGNORESUPERFLAGS		= (1UL << 32),

"1UL" was changed to "1ULL" while applying, but that is not sufficient,
as all other mount flags handling still operates on "unsigned long",
which is 32-bit ont 32-bit platforms.

Hence noreply@ellerman.id.au reported several build failures on 32-bit
platforms (e.g. m68k[1]):

     fs/btrfs/super.c:666:48: error: conversion from 'enum <anonymous>' to 'long unsigned int' changes value from '4294967296' to '0' [-Werror=overflow]

[1] http://kisskb.ellerman.id.au/kisskb/buildresult/15197832/

Gr{oetje,eeting}s,

 						Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
 							    -- Linus Torvalds
diff mbox series

Patch

diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index e4e8e2a56cec..723ea765a05c 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -2346,15 +2346,23 @@  int btrfs_validate_super(const struct btrfs_fs_info *fs_info,
 	u64 nodesize = btrfs_super_nodesize(sb);
 	u64 sectorsize = btrfs_super_sectorsize(sb);
 	int ret = 0;
+	const bool ignore_flags = btrfs_test_opt(fs_info, IGNORESUPERFLAGS);
 
 	if (btrfs_super_magic(sb) != BTRFS_MAGIC) {
 		btrfs_err(fs_info, "no valid FS found");
 		ret = -EINVAL;
 	}
-	if (btrfs_super_flags(sb) & ~BTRFS_SUPER_FLAG_SUPP) {
-		btrfs_err(fs_info, "unrecognized or unsupported super flag: 0x%llx",
-				btrfs_super_flags(sb) & ~BTRFS_SUPER_FLAG_SUPP);
-		ret = -EINVAL;
+	if ((btrfs_super_flags(sb) & ~BTRFS_SUPER_FLAG_SUPP)) {
+		if (!ignore_flags) {
+			btrfs_err(fs_info,
+			"unrecognized or unsupported super flag: 0x%llx",
+				  btrfs_super_flags(sb) & ~BTRFS_SUPER_FLAG_SUPP);
+			ret = -EINVAL;
+		} else {
+			btrfs_info(fs_info,
+			"unrecognized or unsupported super flags: 0x%llx, ignoring",
+				   btrfs_super_flags(sb) & ~BTRFS_SUPER_FLAG_SUPP);
+		}
 	}
 	if (btrfs_super_root_level(sb) >= BTRFS_MAX_LEVEL) {
 		btrfs_err(fs_info, "tree_root level too big: %d >= %d",
diff --git a/fs/btrfs/fs.h b/fs/btrfs/fs.h
index 94faf83eb8d0..5939821dd743 100644
--- a/fs/btrfs/fs.h
+++ b/fs/btrfs/fs.h
@@ -226,6 +226,7 @@  enum {
 	BTRFS_MOUNT_NODISCARD			= (1UL << 29),
 	BTRFS_MOUNT_NOSPACECACHE		= (1UL << 30),
 	BTRFS_MOUNT_IGNOREMETACSUMS		= (1UL << 31),
+	BTRFS_MOUNT_IGNORESUPERFLAGS		= (1UL << 32),
 };
 
 /*
diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c
index 386500b9b440..a66b5c901510 100644
--- a/fs/btrfs/super.c
+++ b/fs/btrfs/super.c
@@ -176,6 +176,7 @@  enum {
 	Opt_rescue_ignorebadroots,
 	Opt_rescue_ignoredatacsums,
 	Opt_rescue_ignoremetacsums,
+	Opt_rescue_ignoresuperflags,
 	Opt_rescue_parameter_all,
 };
 
@@ -186,8 +187,10 @@  static const struct constant_table btrfs_parameter_rescue[] = {
 	{ "ibadroots", Opt_rescue_ignorebadroots },
 	{ "ignoredatacsums", Opt_rescue_ignoredatacsums },
 	{ "ignoremetacsums", Opt_rescue_ignoremetacsums},
+	{ "ignoresuperflags", Opt_rescue_ignoresuperflags},
 	{ "idatacsums", Opt_rescue_ignoredatacsums },
 	{ "imetacsums", Opt_rescue_ignoremetacsums},
+	{ "isuperflags", Opt_rescue_ignoresuperflags},
 	{ "all", Opt_rescue_parameter_all },
 	{}
 };
@@ -576,9 +579,13 @@  static int btrfs_parse_param(struct fs_context *fc, struct fs_parameter *param)
 		case Opt_rescue_ignoremetacsums:
 			btrfs_set_opt(ctx->mount_opt, IGNOREMETACSUMS);
 			break;
+		case Opt_rescue_ignoresuperflags:
+			btrfs_set_opt(ctx->mount_opt, IGNORESUPERFLAGS);
+			break;
 		case Opt_rescue_parameter_all:
 			btrfs_set_opt(ctx->mount_opt, IGNOREDATACSUMS);
 			btrfs_set_opt(ctx->mount_opt, IGNOREMETACSUMS);
+			btrfs_set_opt(ctx->mount_opt, IGNORESUPERFLAGS);
 			btrfs_set_opt(ctx->mount_opt, IGNOREBADROOTS);
 			btrfs_set_opt(ctx->mount_opt, NOLOGREPLAY);
 			break;
@@ -654,7 +661,8 @@  bool btrfs_check_options(const struct btrfs_fs_info *info, unsigned long *mount_
 	    (check_ro_option(info, *mount_opt, BTRFS_MOUNT_NOLOGREPLAY, "nologreplay") ||
 	     check_ro_option(info, *mount_opt, BTRFS_MOUNT_IGNOREBADROOTS, "ignorebadroots") ||
 	     check_ro_option(info, *mount_opt, BTRFS_MOUNT_IGNOREDATACSUMS, "ignoredatacsums") ||
-	     check_ro_option(info, *mount_opt, BTRFS_MOUNT_IGNOREMETACSUMS, "ignoremetacsums")))
+	     check_ro_option(info, *mount_opt, BTRFS_MOUNT_IGNOREMETACSUMS, "ignoremetacsums") ||
+	     check_ro_option(info, *mount_opt, BTRFS_MOUNT_IGNORESUPERFLAGS, "ignoresuperflags")))
 		ret = false;
 
 	if (btrfs_fs_compat_ro(info, FREE_SPACE_TREE) &&
@@ -1072,6 +1080,8 @@  static int btrfs_show_options(struct seq_file *seq, struct dentry *dentry)
 		print_rescue_option(seq, "ignoredatacsums", &printed);
 	if (btrfs_test_opt(info, IGNOREMETACSUMS))
 		print_rescue_option(seq, "ignoremetacsums", &printed);
+	if (btrfs_test_opt(info, IGNORESUPERFLAGS))
+		print_rescue_option(seq, "ignoresuperflags", &printed);
 	if (btrfs_test_opt(info, FLUSHONCOMMIT))
 		seq_puts(seq, ",flushoncommit");
 	if (btrfs_test_opt(info, DISCARD_SYNC))
@@ -1430,6 +1440,7 @@  static void btrfs_emit_options(struct btrfs_fs_info *info,
 	btrfs_info_if_set(info, old, IGNOREBADROOTS, "ignoring bad roots");
 	btrfs_info_if_set(info, old, IGNOREDATACSUMS, "ignoring data csums");
 	btrfs_info_if_set(info, old, IGNOREMETACSUMS, "ignoring meta csums");
+	btrfs_info_if_set(info, old, IGNORESUPERFLAGS, "ignoring unknown super flags");
 
 	btrfs_info_if_unset(info, old, NODATACOW, "setting datacow");
 	btrfs_info_if_unset(info, old, SSD, "not using ssd optimizations");
diff --git a/fs/btrfs/sysfs.c b/fs/btrfs/sysfs.c
index 91e47a3fbedb..94bff7f0f0c4 100644
--- a/fs/btrfs/sysfs.c
+++ b/fs/btrfs/sysfs.c
@@ -386,6 +386,7 @@  static const char *rescue_opts[] = {
 	"ignorebadroots",
 	"ignoredatacsums",
 	"ignoremetacsums",
+	"ignoresuperflags",
 	"all",
 };