Patch "f2fs: fix potential deadlock due to unpaired node_write lock use" has been added to the 6.1-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

This is a note to let you know that I've just added the patch titled

    f2fs: fix potential deadlock due to unpaired node_write lock use

to the 6.1-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     f2fs-fix-potential-deadlock-due-to-unpaired-node_wri.patch
and it can be found in the queue-6.1 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.



commit 4c345f909fdf1363d3da790a1341096fac3f3ac1
Author: Chao Yu <chao@xxxxxxxxxx>
Date:   Sun May 14 16:07:23 2023 +0800

    f2fs: fix potential deadlock due to unpaired node_write lock use
    
    [ Upstream commit f082c6b205a06953f26c40bdc7621cc5a58ceb7c ]
    
    If S_NOQUOTA is cleared from inode during data page writeback of quota
    file, it may miss to unlock node_write lock, result in potential
    deadlock, fix to use the lock in paired.
    
    Kworker                                 Thread
    - writepage
     if (IS_NOQUOTA())
       f2fs_down_read(&sbi->node_write);
                                            - vfs_cleanup_quota_inode
                                             - inode->i_flags &= ~S_NOQUOTA;
     if (IS_NOQUOTA())
       f2fs_up_read(&sbi->node_write);
    
    Fixes: 79963d967b49 ("f2fs: shrink node_write lock coverage")
    Signed-off-by: Chao Yu <chao@xxxxxxxxxx>
    Signed-off-by: Jaegeuk Kim <jaegeuk@xxxxxxxxxx>
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

diff --git a/fs/f2fs/compress.c b/fs/f2fs/compress.c
index b160863eca141..e50d5848c1001 100644
--- a/fs/f2fs/compress.c
+++ b/fs/f2fs/compress.c
@@ -1235,6 +1235,7 @@ static int f2fs_write_compressed_pages(struct compress_ctx *cc,
 	unsigned int last_index = cc->cluster_size - 1;
 	loff_t psize;
 	int i, err;
+	bool quota_inode = IS_NOQUOTA(inode);
 
 	/* we should bypass data pages to proceed the kworkder jobs */
 	if (unlikely(f2fs_cp_error(sbi))) {
@@ -1242,7 +1243,7 @@ static int f2fs_write_compressed_pages(struct compress_ctx *cc,
 		goto out_free;
 	}
 
-	if (IS_NOQUOTA(inode)) {
+	if (quota_inode) {
 		/*
 		 * We need to wait for node_write to avoid block allocation during
 		 * checkpoint. This can only happen to quota writes which can cause
@@ -1364,7 +1365,7 @@ static int f2fs_write_compressed_pages(struct compress_ctx *cc,
 		set_inode_flag(inode, FI_FIRST_BLOCK_WRITTEN);
 
 	f2fs_put_dnode(&dn);
-	if (IS_NOQUOTA(inode))
+	if (quota_inode)
 		f2fs_up_read(&sbi->node_write);
 	else
 		f2fs_unlock_op(sbi);
@@ -1390,7 +1391,7 @@ static int f2fs_write_compressed_pages(struct compress_ctx *cc,
 out_put_dnode:
 	f2fs_put_dnode(&dn);
 out_unlock_op:
-	if (IS_NOQUOTA(inode))
+	if (quota_inode)
 		f2fs_up_read(&sbi->node_write);
 	else
 		f2fs_unlock_op(sbi);
diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
index 36db9aab47790..c230824ab5e6e 100644
--- a/fs/f2fs/data.c
+++ b/fs/f2fs/data.c
@@ -2759,6 +2759,7 @@ int f2fs_write_single_data_page(struct page *page, int *submitted,
 	loff_t psize = (loff_t)(page->index + 1) << PAGE_SHIFT;
 	unsigned offset = 0;
 	bool need_balance_fs = false;
+	bool quota_inode = IS_NOQUOTA(inode);
 	int err = 0;
 	struct f2fs_io_info fio = {
 		.sbi = sbi,
@@ -2816,19 +2817,19 @@ int f2fs_write_single_data_page(struct page *page, int *submitted,
 		goto out;
 
 	/* Dentry/quota blocks are controlled by checkpoint */
-	if (S_ISDIR(inode->i_mode) || IS_NOQUOTA(inode)) {
+	if (S_ISDIR(inode->i_mode) || quota_inode) {
 		/*
 		 * We need to wait for node_write to avoid block allocation during
 		 * checkpoint. This can only happen to quota writes which can cause
 		 * the below discard race condition.
 		 */
-		if (IS_NOQUOTA(inode))
+		if (quota_inode)
 			f2fs_down_read(&sbi->node_write);
 
 		fio.need_lock = LOCK_DONE;
 		err = f2fs_do_write_data_page(&fio);
 
-		if (IS_NOQUOTA(inode))
+		if (quota_inode)
 			f2fs_up_read(&sbi->node_write);
 
 		goto done;