2022-06-30 08:56:18

by Zhang Yi

[permalink] [raw]
Subject: [PATCH] ext4: fix reading leftover inlined symlinks

Since commit 6493792d3299 ("ext4: convert symlink external data block
mapping to bdev"), create new symlink with inline_data is not supported,
but it missing to handle the leftover inlined symlinks, which could
cause below error message and fail to read symlink.

ls: cannot read symbolic link 'foo': Structure needs cleaning

EXT4-fs error (device sda): ext4_map_blocks:605: inode #12: block
2021161080: comm ls: lblock 0 mapped to illegal pblock 2021161080
(length 1)

Fix this regression by adding ext4_read_inline_link(), which read the
inline data directly and convert it through a kmalloced buffer.

Fixes: 6493792d3299 ("ext4: convert symlink external data block mapping to bdev")
Reported-by: Torge Matthies <[email protected]>
Signed-off-by: Zhang Yi <[email protected]>
---
fs/ext4/ext4.h | 1 +
fs/ext4/inline.c | 30 ++++++++++++++++++++++++++++++
fs/ext4/symlink.c | 15 +++++++++++++++
3 files changed, 46 insertions(+)

diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
index 75b8d81b2469..adfc30ee4b7b 100644
--- a/fs/ext4/ext4.h
+++ b/fs/ext4/ext4.h
@@ -3583,6 +3583,7 @@ extern struct buffer_head *ext4_get_first_inline_block(struct inode *inode,
extern int ext4_inline_data_fiemap(struct inode *inode,
struct fiemap_extent_info *fieinfo,
int *has_inline, __u64 start, __u64 len);
+extern void *ext4_read_inline_link(struct inode *inode);

struct iomap;
extern int ext4_inline_data_iomap(struct inode *inode, struct iomap *iomap);
diff --git a/fs/ext4/inline.c b/fs/ext4/inline.c
index cff52ff6549d..1fa36cbe09ec 100644
--- a/fs/ext4/inline.c
+++ b/fs/ext4/inline.c
@@ -6,6 +6,7 @@

#include <linux/iomap.h>
#include <linux/fiemap.h>
+#include <linux/namei.h>
#include <linux/iversion.h>
#include <linux/sched/mm.h>

@@ -1588,6 +1589,35 @@ int ext4_read_inline_dir(struct file *file,
return ret;
}

+void *ext4_read_inline_link(struct inode *inode)
+{
+ struct ext4_iloc iloc;
+ int ret, inline_size;
+ void *link;
+
+ ret = ext4_get_inode_loc(inode, &iloc);
+ if (ret)
+ return ERR_PTR(ret);
+
+ ret = -ENOMEM;
+ inline_size = ext4_get_inline_size(inode);
+ link = kmalloc(inline_size + 1, GFP_NOFS);
+ if (!link)
+ goto out;
+
+ ret = ext4_read_inline_data(inode, link, inline_size, &iloc);
+ if (ret < 0) {
+ kfree(link);
+ goto out;
+ }
+ nd_terminate_link(link, inode->i_size, ret);
+out:
+ if (ret < 0)
+ link = ERR_PTR(ret);
+ brelse(iloc.bh);
+ return link;
+}
+
struct buffer_head *ext4_get_first_inline_block(struct inode *inode,
struct ext4_dir_entry_2 **parent_de,
int *retval)
diff --git a/fs/ext4/symlink.c b/fs/ext4/symlink.c
index d281f5bcc526..3d3ed3c38f56 100644
--- a/fs/ext4/symlink.c
+++ b/fs/ext4/symlink.c
@@ -74,6 +74,21 @@ static const char *ext4_get_link(struct dentry *dentry, struct inode *inode,
struct delayed_call *callback)
{
struct buffer_head *bh;
+ char *inline_link;
+
+ /*
+ * Create a new inlined symlink is not supported, just provide a
+ * method to read the leftovers.
+ */
+ if (ext4_has_inline_data(inode)) {
+ if (!dentry)
+ return ERR_PTR(-ECHILD);
+
+ inline_link = ext4_read_inline_link(inode);
+ if (!IS_ERR(inline_link))
+ set_delayed_call(callback, kfree_link, inline_link);
+ return inline_link;
+ }

if (!dentry) {
bh = ext4_getblk(NULL, inode, 0, EXT4_GET_BLOCKS_CACHED_NOWAIT);
--
2.31.1


2022-06-30 09:12:09

by Zhang Yi

[permalink] [raw]
Subject: Re: [PATCH] ext4: fix reading leftover inlined symlinks

Hi, Torge.

Please take a look at this patch and check could it solve your problem or not.

Thanks,
Yi.

On 2022/6/30 17:01, Zhang Yi wrote:
> Since commit 6493792d3299 ("ext4: convert symlink external data block
> mapping to bdev"), create new symlink with inline_data is not supported,
> but it missing to handle the leftover inlined symlinks, which could
> cause below error message and fail to read symlink.
>
> ls: cannot read symbolic link 'foo': Structure needs cleaning
>
> EXT4-fs error (device sda): ext4_map_blocks:605: inode #12: block
> 2021161080: comm ls: lblock 0 mapped to illegal pblock 2021161080
> (length 1)
>
> Fix this regression by adding ext4_read_inline_link(), which read the
> inline data directly and convert it through a kmalloced buffer.
>
> Fixes: 6493792d3299 ("ext4: convert symlink external data block mapping to bdev")
> Reported-by: Torge Matthies <[email protected]>
> Signed-off-by: Zhang Yi <[email protected]>
> ---
> fs/ext4/ext4.h | 1 +
> fs/ext4/inline.c | 30 ++++++++++++++++++++++++++++++
> fs/ext4/symlink.c | 15 +++++++++++++++
> 3 files changed, 46 insertions(+)
>
> diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
> index 75b8d81b2469..adfc30ee4b7b 100644
> --- a/fs/ext4/ext4.h
> +++ b/fs/ext4/ext4.h
> @@ -3583,6 +3583,7 @@ extern struct buffer_head *ext4_get_first_inline_block(struct inode *inode,
> extern int ext4_inline_data_fiemap(struct inode *inode,
> struct fiemap_extent_info *fieinfo,
> int *has_inline, __u64 start, __u64 len);
> +extern void *ext4_read_inline_link(struct inode *inode);
>
> struct iomap;
> extern int ext4_inline_data_iomap(struct inode *inode, struct iomap *iomap);
> diff --git a/fs/ext4/inline.c b/fs/ext4/inline.c
> index cff52ff6549d..1fa36cbe09ec 100644
> --- a/fs/ext4/inline.c
> +++ b/fs/ext4/inline.c
> @@ -6,6 +6,7 @@
>
> #include <linux/iomap.h>
> #include <linux/fiemap.h>
> +#include <linux/namei.h>
> #include <linux/iversion.h>
> #include <linux/sched/mm.h>
>
> @@ -1588,6 +1589,35 @@ int ext4_read_inline_dir(struct file *file,
> return ret;
> }
>
> +void *ext4_read_inline_link(struct inode *inode)
> +{
> + struct ext4_iloc iloc;
> + int ret, inline_size;
> + void *link;
> +
> + ret = ext4_get_inode_loc(inode, &iloc);
> + if (ret)
> + return ERR_PTR(ret);
> +
> + ret = -ENOMEM;
> + inline_size = ext4_get_inline_size(inode);
> + link = kmalloc(inline_size + 1, GFP_NOFS);
> + if (!link)
> + goto out;
> +
> + ret = ext4_read_inline_data(inode, link, inline_size, &iloc);
> + if (ret < 0) {
> + kfree(link);
> + goto out;
> + }
> + nd_terminate_link(link, inode->i_size, ret);
> +out:
> + if (ret < 0)
> + link = ERR_PTR(ret);
> + brelse(iloc.bh);
> + return link;
> +}
> +
> struct buffer_head *ext4_get_first_inline_block(struct inode *inode,
> struct ext4_dir_entry_2 **parent_de,
> int *retval)
> diff --git a/fs/ext4/symlink.c b/fs/ext4/symlink.c
> index d281f5bcc526..3d3ed3c38f56 100644
> --- a/fs/ext4/symlink.c
> +++ b/fs/ext4/symlink.c
> @@ -74,6 +74,21 @@ static const char *ext4_get_link(struct dentry *dentry, struct inode *inode,
> struct delayed_call *callback)
> {
> struct buffer_head *bh;
> + char *inline_link;
> +
> + /*
> + * Create a new inlined symlink is not supported, just provide a
> + * method to read the leftovers.
> + */
> + if (ext4_has_inline_data(inode)) {
> + if (!dentry)
> + return ERR_PTR(-ECHILD);
> +
> + inline_link = ext4_read_inline_link(inode);
> + if (!IS_ERR(inline_link))
> + set_delayed_call(callback, kfree_link, inline_link);
> + return inline_link;
> + }
>
> if (!dentry) {
> bh = ext4_getblk(NULL, inode, 0, EXT4_GET_BLOCKS_CACHED_NOWAIT);
>

2022-07-03 08:15:31

by Torge Matthies

[permalink] [raw]
Subject: Re: [PATCH] ext4: fix reading leftover inlined symlinks

On Thu, 30 Jun 2022 at 10:51, Zhang Yi <[email protected]> wrote:
>
> Hi, Torge.
>
> Please take a look at this patch and check could it solve your problem or not.
>
> Thanks,
> Yi.

Hello Yi,

Thank you for that patch, it does solve the problem on my system, and
has been stable for a few days.
So you can put my tested-by on the patch if you want:

Tested-by: Torge Matthies <[email protected]>

-Torge

2022-07-08 03:30:53

by Theodore Ts'o

[permalink] [raw]
Subject: Re: [PATCH] ext4: fix reading leftover inlined symlinks

On Thu, 30 Jun 2022 17:01:00 +0800, Zhang Yi wrote:
> Since commit 6493792d3299 ("ext4: convert symlink external data block
> mapping to bdev"), create new symlink with inline_data is not supported,
> but it missing to handle the leftover inlined symlinks, which could
> cause below error message and fail to read symlink.
>
> ls: cannot read symbolic link 'foo': Structure needs cleaning
>
> [...]

Applied, thanks!

[1/1] ext4: fix reading leftover inlined symlinks
commit: f50f5a5eac8092fb9b3365ca4b1d7407cdab8427

Best regards,
--
Theodore Ts'o <[email protected]>