From: Baokun Li via Linux-erofs <linux-erofs@lists.ozlabs.org>
To: <linux-erofs@lists.ozlabs.org>
Cc: brauner@kernel.org, yangerkun@huawei.com,
linux-kernel@vger.kernel.org, huyue2@coolpad.com,
viro@zeniv.linux.org.uk
Subject: [PATCH v2] erofs: reliably distinguish block based and fscache mode
Date: Wed, 17 Apr 2024 14:55:13 +0800 [thread overview]
Message-ID: <20240417065513.3409744-1-libaokun1@huawei.com> (raw)
When erofs_kill_sb() is called in block dev based mode, s_bdev may not have
been initialised yet, and if CONFIG_EROFS_FS_ONDEMAND is enabled, it will
be mistaken for fscache mode, and then attempt to free an anon_dev that has
never been allocated, triggering the following warning:
============================================
ida_free called for id=0 which is not allocated.
WARNING: CPU: 14 PID: 926 at lib/idr.c:525 ida_free+0x134/0x140
Modules linked in:
CPU: 14 PID: 926 Comm: mount Not tainted 6.9.0-rc3-dirty #630
RIP: 0010:ida_free+0x134/0x140
Call Trace:
<TASK>
erofs_kill_sb+0x81/0x90
deactivate_locked_super+0x35/0x80
get_tree_bdev+0x136/0x1e0
vfs_get_tree+0x2c/0xf0
do_new_mount+0x190/0x2f0
[...]
============================================
Instead of allocating the erofs_sb_info in fill_super() allocate it
during erofs_get_tree() and ensure that erofs can always have the info
available during erofs_kill_sb().
Signed-off-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Baokun Li <libaokun1@huawei.com>
---
Changes since v1:
Allocate and initialise fc->s_fs_info in erofs_fc_get_tree() instead of
modifying fc->sb_flags.
V1: https://lore.kernel.org/r/20240415121746.1207242-1-libaokun1@huawei.com/
fs/erofs/super.c | 51 ++++++++++++++++++++++++++----------------------
1 file changed, 28 insertions(+), 23 deletions(-)
diff --git a/fs/erofs/super.c b/fs/erofs/super.c
index b21bd8f78dc1..4104280be2ea 100644
--- a/fs/erofs/super.c
+++ b/fs/erofs/super.c
@@ -581,8 +581,7 @@ static const struct export_operations erofs_export_ops = {
static int erofs_fc_fill_super(struct super_block *sb, struct fs_context *fc)
{
struct inode *inode;
- struct erofs_sb_info *sbi;
- struct erofs_fs_context *ctx = fc->fs_private;
+ struct erofs_sb_info *sbi = EROFS_SB(sb);
int err;
sb->s_magic = EROFS_SUPER_MAGIC;
@@ -590,19 +589,6 @@ static int erofs_fc_fill_super(struct super_block *sb, struct fs_context *fc)
sb->s_maxbytes = MAX_LFS_FILESIZE;
sb->s_op = &erofs_sops;
- sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
- if (!sbi)
- return -ENOMEM;
-
- sb->s_fs_info = sbi;
- sbi->opt = ctx->opt;
- sbi->devs = ctx->devs;
- ctx->devs = NULL;
- sbi->fsid = ctx->fsid;
- ctx->fsid = NULL;
- sbi->domain_id = ctx->domain_id;
- ctx->domain_id = NULL;
-
sbi->blkszbits = PAGE_SHIFT;
if (erofs_is_fscache_mode(sb)) {
sb->s_blocksize = PAGE_SIZE;
@@ -704,11 +690,32 @@ static int erofs_fc_fill_super(struct super_block *sb, struct fs_context *fc)
return 0;
}
-static int erofs_fc_get_tree(struct fs_context *fc)
+static void erofs_ctx_to_info(struct fs_context *fc)
{
struct erofs_fs_context *ctx = fc->fs_private;
+ struct erofs_sb_info *sbi = fc->s_fs_info;
+
+ sbi->opt = ctx->opt;
+ sbi->devs = ctx->devs;
+ ctx->devs = NULL;
+ sbi->fsid = ctx->fsid;
+ ctx->fsid = NULL;
+ sbi->domain_id = ctx->domain_id;
+ ctx->domain_id = NULL;
+}
- if (IS_ENABLED(CONFIG_EROFS_FS_ONDEMAND) && ctx->fsid)
+static int erofs_fc_get_tree(struct fs_context *fc)
+{
+ struct erofs_sb_info *sbi;
+
+ sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
+ if (!sbi)
+ return -ENOMEM;
+
+ fc->s_fs_info = sbi;
+ erofs_ctx_to_info(fc);
+
+ if (IS_ENABLED(CONFIG_EROFS_FS_ONDEMAND) && sbi->fsid)
return get_tree_nodev(fc, erofs_fc_fill_super);
return get_tree_bdev(fc, erofs_fc_fill_super);
@@ -767,6 +774,7 @@ static void erofs_fc_free(struct fs_context *fc)
kfree(ctx->fsid);
kfree(ctx->domain_id);
kfree(ctx);
+ kfree(fc->s_fs_info);
}
static const struct fs_context_operations erofs_context_ops = {
@@ -783,6 +791,7 @@ static int erofs_init_fs_context(struct fs_context *fc)
ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
if (!ctx)
return -ENOMEM;
+
ctx->devs = kzalloc(sizeof(struct erofs_dev_context), GFP_KERNEL);
if (!ctx->devs) {
kfree(ctx);
@@ -799,17 +808,13 @@ static int erofs_init_fs_context(struct fs_context *fc)
static void erofs_kill_sb(struct super_block *sb)
{
- struct erofs_sb_info *sbi;
+ struct erofs_sb_info *sbi = EROFS_SB(sb);
- if (erofs_is_fscache_mode(sb))
+ if (IS_ENABLED(CONFIG_EROFS_FS_ONDEMAND) && sbi->fsid)
kill_anon_super(sb);
else
kill_block_super(sb);
- sbi = EROFS_SB(sb);
- if (!sbi)
- return;
-
erofs_free_dev_context(sbi->devs);
fs_put_dax(sbi->dax_dev, NULL);
erofs_fscache_unregister_fs(sb);
--
2.31.1
next reply other threads:[~2024-04-17 6:54 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-04-17 6:55 Baokun Li via Linux-erofs [this message]
2024-04-18 2:16 ` [PATCH v2] erofs: reliably distinguish block based and fscache mode Jingbo Xu
2024-04-18 3:36 ` Baokun Li via Linux-erofs
2024-04-18 5:50 ` Jingbo Xu
2024-04-18 6:12 ` Baokun Li via Linux-erofs
2024-04-18 7:49 ` Gao Xiang
2024-04-18 8:16 ` Baokun Li via Linux-erofs
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