Hello Ahmad,
On 11/20/23 09:37, Ahmad Fatoum wrote:
Files opened with O_TMPFILE have no name, so read_file can't be used
with them. Therefore add a read_fd function, which slurps all a file's
contents into a buffer.
Signed-off-by: Ahmad Fatoum <a.fatoum@xxxxxxxxxxxxxx>
---
include/libfile.h | 2 ++
lib/libfile.c | 44 ++++++++++++++++++++++++++++++++++++++++++++
2 files changed, 46 insertions(+)
diff --git a/include/libfile.h b/include/libfile.h
index a353ccfa9ea9..423e7ffec5b7 100644
--- a/include/libfile.h
+++ b/include/libfile.h
@@ -12,6 +12,8 @@ char *read_file_line(const char *fmt, ...);
void *read_file(const char *filename, size_t *size);
+void *read_fd(int fd, size_t *size);
+
int read_file_2(const char *filename, size_t *size, void **outbuf,
loff_t max_size);
diff --git a/lib/libfile.c b/lib/libfile.c
index e53ba08415a2..c257baaa2733 100644
--- a/lib/libfile.c
+++ b/lib/libfile.c
@@ -306,6 +306,50 @@ void *read_file(const char *filename, size_t *size)
}
EXPORT_SYMBOL(read_file);
+/**
+ * read_fd - read from a file descriptor to an allocated buffer
+ * @filename: The file descriptor to read
+ * @size: After successful return contains the size of the file
+ *
+ * This function reads a file descriptor from offset 0 until EOF to an
+ * allocated buffer.
+ *
+ * Return: The buffer containing the file or NULL on failure
+ */
+void *read_fd(int fd, size_t *out_size)
+{
+ off_t off;
+ ssize_t ret;
+ size_t size;
+ void *buf;
+
+ off = lseek(fd, SEEK_CUR, 0);
+ if (off >= 0) {
+ size = off;
+ off = lseek(fd, SEEK_SET, 0);
+ }
+ if (off < 0) {
+ ret = off;
+ goto close_fd;
+ }
+
+ buf = malloc(size + 3);
Maybe check the return value from malloc()?
Also, it's not clear to me why this +3 is needed and the 3 extra \0,
maybe an in-code comment would help?
+ ret = read_full(fd, buf, size);
+ if (ret < 0) {
+ free(buf);
+ goto close_fd;
+ }
+
+ memset(&buf[size], '\0', 3);
+ *out_size = size;
+
+close_fd:
+ close(fd);
+
+ return ret < 0 ? NULL : buf;
+}
+EXPORT_SYMBOL(read_fd);
+
/**
* write_file - write a buffer to a file
* @filename: The filename to write
Regards,
--
Yann
