Current btrfs_parse_options() is not atomic, which can set and clear a
bit, especially for nospace_cache case.
For example, if a fs is mounted with nospace_cache,
btrfs_parse_options() will set SPACE_CACHE bit first(since
cache_generation is non-zeo) and clear the SPACE_CACHE bit due to
nospace_cache mount option.
So under heavy operations and remount a nospace_cache btrfs, there is a
windows for commit to create space cache.
This bug can be reproduced by fstest/btrfs/071 073 074 with
nospace_cache mount option. It has about 50% chance to create space
cache, and about 10% chance to create wrong space cache, which can't
pass btrfsck.
This patch will do the mount option parse in a copy-and-update method.
First copy the mount_opt from fs_info to new_opt, and only update
options in new_opt. At last, copy the new_opt back to
fs_info->mount_opt.
This patch is already good enough to fix the above nospace_cache +
remount bug, but need later patch to make sure mount options does not
change during transaction.
Signed-off-by: Qu Wenruo <quwen...@cn.fujitsu.com>
---
fs/btrfs/ctree.h | 16 +++----
fs/btrfs/inode-map.c | 3 +-
fs/btrfs/super.c | 115 +++++++++++++++++++++++++++------------------------
3 files changed, 71 insertions(+), 63 deletions(-)
diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index 5f99743..26bb47b 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -2119,18 +2119,18 @@ struct btrfs_ioctl_defrag_range_args {
#define btrfs_test_opt(root, opt) ((root)->fs_info->mount_opt & \
BTRFS_MOUNT_##opt)
-#define btrfs_set_and_info(root, opt, fmt, args...) \
+#define btrfs_set_and_info(fs_info, val, opt, fmt, args...) \
{ \
- if (!btrfs_test_opt(root, opt)) \
- btrfs_info(root->fs_info, fmt, ##args); \
- btrfs_set_opt(root->fs_info->mount_opt, opt); \
+ if (!btrfs_raw_test_opt(val, opt)) \
+ btrfs_info(fs_info, fmt, ##args); \
+ btrfs_set_opt(val, opt); \
}
-#define btrfs_clear_and_info(root, opt, fmt, args...) \
+#define btrfs_clear_and_info(fs_info, val, opt, fmt, args...) \
{ \
- if (btrfs_test_opt(root, opt)) \
- btrfs_info(root->fs_info, fmt, ##args); \
- btrfs_clear_opt(root->fs_info->mount_opt, opt); \
+ if (btrfs_raw_test_opt(val, opt)) \
+ btrfs_info(fs_info, fmt, ##args); \
+ btrfs_clear_opt(val, opt); \
}
/*
diff --git a/fs/btrfs/inode-map.c b/fs/btrfs/inode-map.c
index 81efd83..d1edab5 100644
--- a/fs/btrfs/inode-map.c
+++ b/fs/btrfs/inode-map.c
@@ -178,7 +178,8 @@ static void start_caching(struct btrfs_root *root)
root->root_key.objectid);
if (IS_ERR(tsk)) {
btrfs_warn(root->fs_info, "failed to start inode caching task");
- btrfs_clear_and_info(root, CHANGE_INODE_CACHE,
+ btrfs_clear_and_info(root->fs_info, root->fs_info->mount_opt,
+ CHANGE_INODE_CACHE,
"disabling inode map caching");
}
}
diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c
index b0c45b2..490fe1f 100644
--- a/fs/btrfs/super.c
+++ b/fs/btrfs/super.c
@@ -395,10 +395,13 @@ int btrfs_parse_options(struct btrfs_root *root, char
*options)
int ret = 0;
char *compress_type;
bool compress_force = false;
+ unsigned long new_opt;
+
+ new_opt = info->mount_opt;
cache_gen = btrfs_super_cache_generation(root->fs_info->super_copy);
if (cache_gen)
- btrfs_set_opt(info->mount_opt, SPACE_CACHE);
+ btrfs_set_opt(new_opt, SPACE_CACHE);
if (!options)
goto out;
@@ -422,7 +425,7 @@ int btrfs_parse_options(struct btrfs_root *root, char
*options)
switch (token) {
case Opt_degraded:
btrfs_info(root->fs_info, "allowing degraded mounts");
- btrfs_set_opt(info->mount_opt, DEGRADED);
+ btrfs_set_opt(new_opt, DEGRADED);
break;
case Opt_subvol:
case Opt_subvolid:
@@ -434,7 +437,7 @@ int btrfs_parse_options(struct btrfs_root *root, char
*options)
*/
break;
case Opt_nodatasum:
- btrfs_set_and_info(root, NODATASUM,
+ btrfs_set_and_info(info, new_opt, NODATASUM,
"setting nodatasum");
break;
case Opt_datasum:
@@ -444,8 +447,8 @@ int btrfs_parse_options(struct btrfs_root *root, char
*options)
else
btrfs_info(root->fs_info, "setting
datasum");
}
- btrfs_clear_opt(info->mount_opt, NODATACOW);
- btrfs_clear_opt(info->mount_opt, NODATASUM);
+ btrfs_clear_opt(new_opt, NODATACOW);
+ btrfs_clear_opt(new_opt, NODATASUM);
break;
case Opt_nodatacow:
if (!btrfs_test_opt(root, NODATACOW)) {
@@ -457,13 +460,13 @@ int btrfs_parse_options(struct btrfs_root *root, char
*options)
btrfs_info(root->fs_info, "setting
nodatacow");
}
}
- btrfs_clear_opt(info->mount_opt, COMPRESS);
- btrfs_clear_opt(info->mount_opt, FORCE_COMPRESS);
- btrfs_set_opt(info->mount_opt, NODATACOW);
- btrfs_set_opt(info->mount_opt, NODATASUM);
+ btrfs_clear_opt(new_opt, COMPRESS);
+ btrfs_clear_opt(new_opt, FORCE_COMPRESS);
+ btrfs_set_opt(new_opt, NODATACOW);
+ btrfs_set_opt(new_opt, NODATASUM);
break;
case Opt_datacow:
- btrfs_clear_and_info(root, NODATACOW,
+ btrfs_clear_and_info(info, new_opt, NODATACOW,
"setting datacow");
break;
case Opt_compress_force:
@@ -477,20 +480,20 @@ int btrfs_parse_options(struct btrfs_root *root, char
*options)
strcmp(args[0].from, "zlib") == 0) {
compress_type = "zlib";
info->compress_type = BTRFS_COMPRESS_ZLIB;
- btrfs_set_opt(info->mount_opt, COMPRESS);
- btrfs_clear_opt(info->mount_opt, NODATACOW);
- btrfs_clear_opt(info->mount_opt, NODATASUM);
+ btrfs_set_opt(new_opt, COMPRESS);
+ btrfs_clear_opt(new_opt, NODATACOW);
+ btrfs_clear_opt(new_opt, NODATASUM);
} else if (strcmp(args[0].from, "lzo") == 0) {
compress_type = "lzo";
info->compress_type = BTRFS_COMPRESS_LZO;
- btrfs_set_opt(info->mount_opt, COMPRESS);
- btrfs_clear_opt(info->mount_opt, NODATACOW);
- btrfs_clear_opt(info->mount_opt, NODATASUM);
+ btrfs_set_opt(new_opt, COMPRESS);
+ btrfs_clear_opt(new_opt, NODATACOW);
+ btrfs_clear_opt(new_opt, NODATASUM);
btrfs_set_fs_incompat(info, COMPRESS_LZO);
} else if (strncmp(args[0].from, "no", 2) == 0) {
compress_type = "no";
- btrfs_clear_opt(info->mount_opt, COMPRESS);
- btrfs_clear_opt(info->mount_opt,
FORCE_COMPRESS);
+ btrfs_clear_opt(new_opt, COMPRESS);
+ btrfs_clear_opt(new_opt, FORCE_COMPRESS);
compress_force = false;
} else {
ret = -EINVAL;
@@ -498,7 +501,8 @@ int btrfs_parse_options(struct btrfs_root *root, char
*options)
}
if (compress_force) {
- btrfs_set_and_info(root, FORCE_COMPRESS,
+ btrfs_set_and_info(info, new_opt,
+ FORCE_COMPRESS,
"force %s compression",
compress_type);
} else {
@@ -512,29 +516,29 @@ int btrfs_parse_options(struct btrfs_root *root, char
*options)
* flag, otherwise, there is no way for users
* to disable forcible compression separately.
*/
- btrfs_clear_opt(info->mount_opt,
FORCE_COMPRESS);
+ btrfs_clear_opt(new_opt, FORCE_COMPRESS);
}
break;
case Opt_ssd:
- btrfs_set_and_info(root, SSD,
+ btrfs_set_and_info(info, new_opt, SSD,
"use ssd allocation scheme");
break;
case Opt_ssd_spread:
- btrfs_set_and_info(root, SSD_SPREAD,
+ btrfs_set_and_info(info, new_opt, SSD_SPREAD,
"use spread ssd allocation scheme");
- btrfs_set_opt(info->mount_opt, SSD);
+ btrfs_set_opt(new_opt, SSD);
break;
case Opt_nossd:
- btrfs_set_and_info(root, NOSSD,
- "not using ssd allocation scheme");
- btrfs_clear_opt(info->mount_opt, SSD);
+ btrfs_set_and_info(info, new_opt, NOSSD,
+ "not using ssd allocation scheme");
+ btrfs_clear_opt(new_opt, SSD);
break;
case Opt_barrier:
- btrfs_clear_and_info(root, NOBARRIER,
+ btrfs_clear_and_info(info, new_opt, NOBARRIER,
"turning on barriers");
break;
case Opt_nobarrier:
- btrfs_set_and_info(root, NOBARRIER,
+ btrfs_set_and_info(info, new_opt, NOBARRIER,
"turning off barriers");
break;
case Opt_thread_pool:
@@ -594,19 +598,19 @@ int btrfs_parse_options(struct btrfs_root *root, char
*options)
root->fs_info->sb->s_flags &= ~MS_POSIXACL;
break;
case Opt_notreelog:
- btrfs_set_and_info(root, NOTREELOG,
+ btrfs_set_and_info(info, new_opt, NOTREELOG,
"disabling tree log");
break;
case Opt_treelog:
- btrfs_clear_and_info(root, NOTREELOG,
+ btrfs_clear_and_info(info, new_opt, NOTREELOG,
"enabling tree log");
break;
case Opt_flushoncommit:
- btrfs_set_and_info(root, FLUSHONCOMMIT,
+ btrfs_set_and_info(info, new_opt, FLUSHONCOMMIT,
"turning on flush-on-commit");
break;
case Opt_noflushoncommit:
- btrfs_clear_and_info(root, FLUSHONCOMMIT,
+ btrfs_clear_and_info(info, new_opt, FLUSHONCOMMIT,
"turning off flush-on-commit");
break;
case Opt_ratio:
@@ -623,71 +627,71 @@ int btrfs_parse_options(struct btrfs_root *root, char
*options)
}
break;
case Opt_discard:
- btrfs_set_and_info(root, DISCARD,
+ btrfs_set_and_info(info, new_opt, DISCARD,
"turning on discard");
break;
case Opt_nodiscard:
- btrfs_clear_and_info(root, DISCARD,
+ btrfs_clear_and_info(info, new_opt, DISCARD,
"turning off discard");
break;
case Opt_space_cache:
- btrfs_set_and_info(root, SPACE_CACHE,
+ btrfs_set_and_info(info, new_opt, SPACE_CACHE,
"enabling disk space caching");
break;
case Opt_rescan_uuid_tree:
- btrfs_set_opt(info->mount_opt, RESCAN_UUID_TREE);
+ btrfs_set_opt(new_opt, RESCAN_UUID_TREE);
break;
case Opt_no_space_cache:
- btrfs_clear_and_info(root, SPACE_CACHE,
+ btrfs_clear_and_info(info, new_opt, SPACE_CACHE,
"disabling disk space caching");
break;
case Opt_inode_cache:
- btrfs_set_pending_and_info(info, INODE_MAP_CACHE,
+ btrfs_set_and_info(info, new_opt, INODE_MAP_CACHE,
"enabling inode map caching");
break;
case Opt_noinode_cache:
- btrfs_clear_pending_and_info(info, INODE_MAP_CACHE,
+ btrfs_clear_and_info(info, new_opt, INODE_MAP_CACHE,
"disabling inode map caching");
break;
case Opt_clear_cache:
- btrfs_set_and_info(root, CLEAR_CACHE,
+ btrfs_set_and_info(info, new_opt, CLEAR_CACHE,
"force clearing of disk cache");
break;
case Opt_user_subvol_rm_allowed:
- btrfs_set_opt(info->mount_opt, USER_SUBVOL_RM_ALLOWED);
+ btrfs_set_opt(new_opt, USER_SUBVOL_RM_ALLOWED);
break;
case Opt_enospc_debug:
- btrfs_set_opt(info->mount_opt, ENOSPC_DEBUG);
+ btrfs_set_opt(new_opt, ENOSPC_DEBUG);
break;
case Opt_noenospc_debug:
- btrfs_clear_opt(info->mount_opt, ENOSPC_DEBUG);
+ btrfs_clear_opt(new_opt, ENOSPC_DEBUG);
break;
case Opt_defrag:
- btrfs_set_and_info(root, AUTO_DEFRAG,
+ btrfs_set_and_info(info, new_opt, AUTO_DEFRAG,
"enabling auto defrag");
break;
case Opt_nodefrag:
- btrfs_clear_and_info(root, AUTO_DEFRAG,
+ btrfs_clear_and_info(info, new_opt, AUTO_DEFRAG,
"disabling auto defrag");
break;
case Opt_recovery:
btrfs_info(root->fs_info, "enabling auto recovery");
- btrfs_set_opt(info->mount_opt, RECOVERY);
+ btrfs_set_opt(new_opt, RECOVERY);
break;
case Opt_skip_balance:
- btrfs_set_opt(info->mount_opt, SKIP_BALANCE);
+ btrfs_set_opt(new_opt, SKIP_BALANCE);
break;
#ifdef CONFIG_BTRFS_FS_CHECK_INTEGRITY
case Opt_check_integrity_including_extent_data:
btrfs_info(root->fs_info,
"enabling check integrity including extent
data");
- btrfs_set_opt(info->mount_opt,
+ btrfs_set_opt(new_opt,
CHECK_INTEGRITY_INCLUDING_EXTENT_DATA);
- btrfs_set_opt(info->mount_opt, CHECK_INTEGRITY);
+ btrfs_set_opt(new_opt, CHECK_INTEGRITY);
break;
case Opt_check_integrity:
btrfs_info(root->fs_info, "enabling check integrity");
- btrfs_set_opt(info->mount_opt, CHECK_INTEGRITY);
+ btrfs_set_opt(new_opt, CHECK_INTEGRITY);
break;
case Opt_check_integrity_print_mask:
ret = match_int(&args[0], &intarg);
@@ -713,10 +717,10 @@ int btrfs_parse_options(struct btrfs_root *root, char
*options)
#endif
case Opt_fatal_errors:
if (strcmp(args[0].from, "panic") == 0)
- btrfs_set_opt(info->mount_opt,
+ btrfs_set_opt(new_opt,
PANIC_ON_FATAL_ERROR);
else if (strcmp(args[0].from, "bug") == 0)
- btrfs_clear_opt(info->mount_opt,
+ btrfs_clear_opt(new_opt,
PANIC_ON_FATAL_ERROR);
else {
ret = -EINVAL;
@@ -752,8 +756,11 @@ int btrfs_parse_options(struct btrfs_root *root, char
*options)
}
}
out:
- if (!ret && btrfs_test_opt(root, SPACE_CACHE))
- btrfs_info(root->fs_info, "disk space caching is enabled");
+ if (!ret) {
+ if (btrfs_raw_test_opt(new_opt, SPACE_CACHE))
+ btrfs_info(info, "disk space caching is enabled");
+ info->mount_opt = new_opt;
+ }
kfree(orig);
return ret;
}
--
2.2.2
--
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