Merge tag 'master-2014-11-20' of git://git.kernel.org/pub/scm/linux/kernel/git/linvil...

[cascardo/linux.git] / drivers / staging / android / logger.c

diff --git a/drivers/staging/android/logger.c b/drivers/staging/android/logger.c
index 28b93d3..a673ffa 100644 (file)
--- a/drivers/staging/android/logger.c
+++ b/drivers/staging/android/logger.c
@@ -420,7 +420,7 @@ static ssize_t logger_write_iter(struct kiocb *iocb, struct iov_iter *from)
        struct logger_log *log = file_get_log(iocb->ki_filp);
        struct logger_entry header;
        struct timespec now;
-       size_t len, count;
+       size_t len, count, w_off;
 
        count = min_t(size_t, iocb->ki_nbytes, LOGGER_ENTRY_MAX_PAYLOAD);
 
@@ -452,11 +452,14 @@ static ssize_t logger_write_iter(struct kiocb *iocb, struct iov_iter *from)
        memcpy(log->buffer + log->w_off, &header, len);
        memcpy(log->buffer, (char *)&header + len, sizeof(header) - len);
 
-       len = min(count, log->size - log->w_off);
+       /* Work with a copy until we are ready to commit the whole entry */
+       w_off =  logger_offset(log, log->w_off + sizeof(struct logger_entry));
 
-       if (copy_from_iter(log->buffer + log->w_off, len, from) != len) {
+       len = min(count, log->size - w_off);
+
+       if (copy_from_iter(log->buffer + w_off, len, from) != len) {
                /*
-                * Note that by not updating w_off, this abandons the
+                * Note that by not updating log->w_off, this abandons the
                 * portion of the new entry that *was* successfully
                 * copied, just above.  This is intentional to avoid
                 * message corruption from missing fragments.
@@ -470,7 +473,7 @@ static ssize_t logger_write_iter(struct kiocb *iocb, struct iov_iter *from)
                return -EFAULT;
        }
 
-       log->w_off = logger_offset(log, log->w_off + count);
+       log->w_off = logger_offset(log, w_off + count);
        mutex_unlock(&log->mutex);
 
        /* wake up any blocked readers */