* [PATCH v2 1/2] ext4: optimize ea_inode block expansion
2023-01-03 1:45 [PATCH v2 0/2] optimize ea_inode block expansion to fix panic Jun Nie
@ 2023-01-03 1:45 ` Jun Nie
2023-01-03 1:45 ` [PATCH v2 2/2] ext4: refuse to create ea block when umounted Jun Nie
2023-02-19 5:40 ` [PATCH v2 0/2] optimize ea_inode block expansion to fix panic Theodore Ts'o
2 siblings, 0 replies; 4+ messages in thread
From: Jun Nie @ 2023-01-03 1:45 UTC (permalink / raw)
To: tytso, adilger.kernel, linux-ext4, linux-kernel; +Cc: tudor.ambarus
Copy ea data from inode entry when expanding ea block if possible.
Then remove the ea entry if expansion success. Thus memcpy to a
temporary buffer may be avoided.
If the expansion fails, we do not need to recovery the removed ea
entry neither in this way.
Signed-off-by: Jun Nie <jun.nie@linaro.org>
---
fs/ext4/xattr.c | 28 +++++++++++++++++-----------
1 file changed, 17 insertions(+), 11 deletions(-)
diff --git a/fs/ext4/xattr.c b/fs/ext4/xattr.c
index 7decaaf27e82..235a517d9c17 100644
--- a/fs/ext4/xattr.c
+++ b/fs/ext4/xattr.c
@@ -2551,9 +2551,8 @@ static int ext4_xattr_move_to_block(handle_t *handle, struct inode *inode,
is = kzalloc(sizeof(struct ext4_xattr_ibody_find), GFP_NOFS);
bs = kzalloc(sizeof(struct ext4_xattr_block_find), GFP_NOFS);
- buffer = kvmalloc(value_size, GFP_NOFS);
b_entry_name = kmalloc(entry->e_name_len + 1, GFP_NOFS);
- if (!is || !bs || !buffer || !b_entry_name) {
+ if (!is || !bs || !b_entry_name) {
error = -ENOMEM;
goto out;
}
@@ -2565,12 +2564,18 @@ static int ext4_xattr_move_to_block(handle_t *handle, struct inode *inode,
/* Save the entry name and the entry value */
if (entry->e_value_inum) {
+ buffer = kvmalloc(value_size, GFP_NOFS);
+ if (!buffer) {
+ error = -ENOMEM;
+ goto out;
+ }
+
error = ext4_xattr_inode_get(inode, entry, buffer, value_size);
if (error)
goto out;
} else {
size_t value_offs = le16_to_cpu(entry->e_value_offs);
- memcpy(buffer, (void *)IFIRST(header) + value_offs, value_size);
+ buffer = (void *)IFIRST(header) + value_offs;
}
memcpy(b_entry_name, entry->e_name, entry->e_name_len);
@@ -2585,25 +2590,26 @@ static int ext4_xattr_move_to_block(handle_t *handle, struct inode *inode,
if (error)
goto out;
- /* Remove the chosen entry from the inode */
- error = ext4_xattr_ibody_set(handle, inode, &i, is);
- if (error)
- goto out;
-
i.value = buffer;
i.value_len = value_size;
error = ext4_xattr_block_find(inode, &i, bs);
if (error)
goto out;
- /* Add entry which was removed from the inode into the block */
+ /* Move ea entry from the inode into the block */
error = ext4_xattr_block_set(handle, inode, &i, bs);
if (error)
goto out;
- error = 0;
+
+ /* Remove the chosen entry from the inode */
+ i.value = NULL;
+ i.value_len = 0;
+ error = ext4_xattr_ibody_set(handle, inode, &i, is);
+
out:
kfree(b_entry_name);
- kvfree(buffer);
+ if (entry->e_value_inum && buffer)
+ kvfree(buffer);
if (is)
brelse(is->iloc.bh);
if (bs)
--
2.34.1
^ permalink raw reply [flat|nested] 4+ messages in thread* [PATCH v2 2/2] ext4: refuse to create ea block when umounted
2023-01-03 1:45 [PATCH v2 0/2] optimize ea_inode block expansion to fix panic Jun Nie
2023-01-03 1:45 ` [PATCH v2 1/2] ext4: optimize ea_inode block expansion Jun Nie
@ 2023-01-03 1:45 ` Jun Nie
2023-02-19 5:40 ` [PATCH v2 0/2] optimize ea_inode block expansion to fix panic Theodore Ts'o
2 siblings, 0 replies; 4+ messages in thread
From: Jun Nie @ 2023-01-03 1:45 UTC (permalink / raw)
To: tytso, adilger.kernel, linux-ext4, linux-kernel; +Cc: tudor.ambarus
The ea block expansion need to access s_root while it is
already set as NULL when umount is triggered. Refuse this
request to avoid panic.
Reported-by: syzbot+2dacb8f015bf1420155f@syzkaller.appspotmail.com
Link: https://syzkaller.appspot.com/bug?id=3613786cb88c93aa1c6a279b1df6a7b201347d08
Signed-off-by: Jun Nie <jun.nie@linaro.org>
---
fs/ext4/xattr.c | 7 +++++++
1 file changed, 7 insertions(+)
diff --git a/fs/ext4/xattr.c b/fs/ext4/xattr.c
index 235a517d9c17..b350510b798c 100644
--- a/fs/ext4/xattr.c
+++ b/fs/ext4/xattr.c
@@ -1422,6 +1422,13 @@ static struct inode *ext4_xattr_inode_create(handle_t *handle,
uid_t owner[2] = { i_uid_read(inode), i_gid_read(inode) };
int err;
+ if (inode->i_sb->s_root == NULL) {
+ ext4_warning(inode->i_sb,
+ "refuse to create EA inode when umounting");
+ WARN_ON(1);
+ return ERR_PTR(-EINVAL);
+ }
+
/*
* Let the next inode be the goal, so we try and allocate the EA inode
* in the same group, or nearby one.
--
2.34.1
^ permalink raw reply [flat|nested] 4+ messages in thread