[PATCH RFC 6/8] fs: sandboxfs: add sandbox_fs_get_blocksize()
Qu Wenruo
wqu at suse.com
Tue Jun 28 17:28:06 AEST 2022
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 at chromium.org>
Signed-off-by: Qu Wenruo <wqu at 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(-)
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);
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
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