libext2fs: unix_io: reflect error from read/write calls to caller

If the read(2) or write(2) system calls fail, return the error to the
caller instead of returning "short read" or "short write", which is
just misleading.

Signed-off-by: Theodore Ts'o <tytso@mit.edu>

diff --git a/lib/ext2fs/unix_io.c b/lib/ext2fs/unix_io.c
index 85ad4e3..429ea24 100644 (file)
--- a/lib/ext2fs/unix_io.c
+++ b/lib/ext2fs/unix_io.c
@@ -208,9 +208,11 @@ static errcode_t raw_read_blk(io_channel channel,
                actual = read(data->dev, buf, size);
                if (actual != size) {
                short_read:
-                       if (actual < 0)
+                       if (actual < 0) {
+                               retval = errno;
                                actual = 0;
-                       retval = EXT2_ET_SHORT_READ;
+                       } else
+                               retval = EXT2_ET_SHORT_READ;
                        goto error_out;
                }
                return 0;
@@ -313,6 +315,10 @@ static errcode_t raw_write_blk(io_channel channel,
            (IS_ALIGNED(buf, channel->align) &&
             IS_ALIGNED(size, channel->align))) {
                actual = write(data->dev, buf, size);
+               if (actual < 0) {
+                       retval = errno;
+                       goto error_out;
+               }
                if (actual != size) {
                short_write:
                        retval = EXT2_ET_SHORT_WRITE;
@@ -336,7 +342,7 @@ bounce_write:
                                      channel->block_size);
                        if (actual != channel->block_size) {
                                if (actual < 0) {
-                                       retval = EXT2_ET_SHORT_READ;
+                                       retval = errno;
                                        goto error_out;
                                }
                                memset(data->bounce + actual, 0,
@@ -352,6 +358,10 @@ bounce_write:
                        goto error_out;
                }
                actual = write(data->dev, data->bounce, channel->block_size);
+               if (actual < 0) {
+                       retval = errno;
+                       goto error_out;
+               }
                if (actual != channel->block_size)
                        goto short_write;
                size -= actual;
@@ -997,6 +1007,8 @@ static errcode_t unix_write_byte(io_channel channel, unsigned long offset,
                return errno;
 
        actual = write(data->dev, buf, size);
+       if (actual < 0)
+               return errno;
        if (actual != size)
                return EXT2_ET_SHORT_WRITE;