Re: [PATCH v2] erofs: fix blksize < PAGE_SIZE in fileio mode

[Gao Xiang]

On 2024/10/15 14:40, Hongzhen Luo wrote:

In fileio mode, when blcksize is not equal to PAGE_SIZE,
erofs will attempt to set the block size of sb->s_bdev,
which will trigger a panic. This patch fixes this.

Please fix trivial typos:

erofs: fix blksize < PAGE_SIZE for file-backed mounts


Adjust sb->s_blocksize{,_bits} directly for file-backed
mounts when the fs block size is smaller than PAGE_SIZE.

Previously, EROFS used sb_set_blocksize(), which caused
a panic if bdev-backed mounts is not used.

Fixes: fb176750266a ("erofs: add file-backed mount support")

Unnecessary blank line.

Signed-off-by: Hongzhen Luo <hongz...@linux.alibaba.com>
---
v2: Add support for blocksize < PAGE_SIZE in file-backed mount mode.
v1: 
https://lore.kernel.org/linux-erofs/20241015033601.3206952-1-hongz...@linux.alibaba.com/
---
  fs/erofs/super.c | 12 +++++++++---
  1 file changed, 9 insertions(+), 3 deletions(-)

diff --git a/fs/erofs/super.c b/fs/erofs/super.c
index 320d586c3896..abe2d85512dd 100644
--- a/fs/erofs/super.c
+++ b/fs/erofs/super.c
@@ -631,9 +631,15 @@ static int erofs_fc_fill_super(struct super_block *sb, 
struct fs_context *fc)
                        errorfc(fc, "unsupported blksize for fscache mode");
                        return -EINVAL;
                }
-               if (!sb_set_blocksize(sb, 1 << sbi->blkszbits)) {
-                       errorfc(fc, "failed to set erofs blksize");
-                       return -EINVAL;
+
+               if (erofs_is_fileio_mode(sbi)) {
+                       sb->s_blocksize = (1 << sbi->blkszbits);
+                       sb->s_blocksize_bits = sbi->blkszbits;
+               } else {
+                       if (!sb_set_blocksize(sb, 1 << sbi->blkszbits)) {
+                               errorfc(fc, "failed to set erofs blksize");
+                               return -EINVAL;
+                       }

Please use

                } else if (!sb_set_blocksize(sb, 1 << sbi->blkszbits)) {
                        errorfc(fc, "failed to set erofs blksize");
                        return -EINVAL;
                }
Here.

Thanks,
Gao Xiang

                }
        }