Re: [PATCH RFC 6/8] fs: sandboxfs: add sandbox_fs_get_blocksize()

On Tue, 28 Jun 2022 at 01:28, Qu Wenruo wqu@suse.com wrote:

This is to make sandboxfs to report blocksize it supports for _fs_read() to handle unaligned read.

Unlike all other fses, sandboxfs can handle unaligned read/write without any problem since it's calling read()/write(), which doesn't bother the blocksize at all.

This change is mostly to make testing of _fs_read() much easier.

Cc: Simon Glass sjg@chromium.org Signed-off-by: Qu Wenruo wqu@suse.com

---

arch/sandbox/cpu/os.c | 11 +++++++++++ fs/fs.c | 2 +- fs/sandbox/sandboxfs.c | 14 ++++++++++++++ include/os.h | 8 ++++++++ include/sandboxfs.h | 1 + 5 files changed, 35 insertions(+), 1 deletion(-)

Reviewed-by: Simon Glass sjg@chromium.org

with a comment as requested below

diff --git a/arch/sandbox/cpu/os.c b/arch/sandbox/cpu/os.c index 5ea54179176c..6c29f29bdd9b 100644 --- a/arch/sandbox/cpu/os.c +++ b/arch/sandbox/cpu/os.c @@ -46,6 +46,17 @@ ssize_t os_read(int fd, void *buf, size_t count) return read(fd, buf, count); }

+ssize_t os_get_blocksize(int fd) +{

•   struct stat stat = {0};
  

•   int ret;
  

•   ret = fstat(fd, &stat);
  

•   if (ret < 0)
  

•           return -errno;
  

•   return stat.st_blksize;
  

+}

ssize_t os_write(int fd, const void *buf, size_t count) { return write(fd, buf, count); diff --git a/fs/fs.c b/fs/fs.c index 7e4ead9b790b..337d5711c28c 100644 --- a/fs/fs.c +++ b/fs/fs.c @@ -261,7 +261,7 @@ static struct fstype_info fstypes[] = { .exists = sandbox_fs_exists, .size = sandbox_fs_size, .read = fs_read_sandbox,

•           .get_blocksize = fs_get_blocksize_unsupported,
  

•           .get_blocksize = sandbox_fs_get_blocksize,
            .write = fs_write_sandbox,
            .uuid = fs_uuid_unsupported,
            .opendir = fs_opendir_unsupported,
  

diff --git a/fs/sandbox/sandboxfs.c b/fs/sandbox/sandboxfs.c index 4ae41d5b4db1..130fee088621 100644 --- a/fs/sandbox/sandboxfs.c +++ b/fs/sandbox/sandboxfs.c @@ -55,6 +55,20 @@ int sandbox_fs_read_at(const char *filename, loff_t pos, void *buffer, return ret; }

+int sandbox_fs_get_blocksize(const char *filename) +{

•   int fd;
  

•   int ret;
  

•   fd = os_open(filename, OS_O_RDONLY);
  

•   if (fd < 0)
  

•           return fd;
  

•   ret = os_get_blocksize(fd);
  

•   os_close(fd);
  

•   return ret;
  

+}

int sandbox_fs_write_at(const char *filename, loff_t pos, void *buffer, loff_t towrite, loff_t *actwrite) { diff --git a/include/os.h b/include/os.h index 10e198cf503e..a864d9ca39b2 100644 --- a/include/os.h +++ b/include/os.h @@ -26,6 +26,14 @@ struct sandbox_state; */ ssize_t os_read(int fd, void *buf, size_t count);

+/**

• • Get the optimial blocksize through stat() call.
• • @fd: File descriptor as returned by os_open()
• • Return: >=0 for the blocksize. <0 for error.
• */

+ssize_t os_get_blocksize(int fd);

/**

• Access to the OS write() system call

diff --git a/include/sandboxfs.h b/include/sandboxfs.h index 783dd5c88a73..6937068f7b82 100644 --- a/include/sandboxfs.h +++ b/include/sandboxfs.h @@ -32,6 +32,7 @@ void sandbox_fs_close(void); int sandbox_fs_ls(const char *dirname); int sandbox_fs_exists(const char *filename); int sandbox_fs_size(const char *filename, loff_t *size); +int sandbox_fs_get_blocksize(const char *filename);

Please add a full comment.

int fs_read_sandbox(const char *filename, void *buf, loff_t offset, loff_t len, loff_t *actread); int fs_write_sandbox(const char *filename, void *buf, loff_t offset, -- 2.36.1

Regards, Simon