diff options
Diffstat (limited to 'lib/libfile.c')
-rw-r--r-- | lib/libfile.c | 25 |
1 files changed, 25 insertions, 0 deletions
diff --git a/lib/libfile.c b/lib/libfile.c index 6b373f05ca..1f533133c5 100644 --- a/lib/libfile.c +++ b/lib/libfile.c @@ -76,6 +76,31 @@ int write_full(int fd, const void *buf, size_t size) EXPORT_SYMBOL(write_full); /* + * pread_full - read to filedescriptor at offset + * + * Like pread, but this function only returns less bytes than + * requested when the end of file is reached. + */ +int pread_full(int fd, void *buf, size_t size, loff_t offset) +{ + size_t insize = size; + int now; + + while (size) { + now = pread(fd, buf, size, offset); + if (now == 0) + break; + if (now < 0) + return now; + size -= now; + buf += now; + } + + return insize - size; +} +EXPORT_SYMBOL(pread_full); + +/* * read_full - read from filedescriptor * * Like read, but this function only returns less bytes than |