libext2fs: fix offset support in unix_io.c

Added offset support to the following functions:
- unix_cache_readahead
- unix_discard
- unix_zeroout

Signed-off-by: Marcus Huewe <suse-tux@gmx.de>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

diff --git a/lib/ext2fs/unix_io.c b/lib/ext2fs/unix_io.c
index e419e9d..1657f54 100644 (file)
--- a/lib/ext2fs/unix_io.c
+++ b/lib/ext2fs/unix_io.c
@@ -848,8 +848,9 @@ static errcode_t unix_cache_readahead(io_channel channel,
        struct unix_private_data *data;
 
        data = (struct unix_private_data *)channel->private_data;
+       EXT2_CHECK_MAGIC(data, EXT2_ET_MAGIC_UNIX_IO_CHANNEL);
        return posix_fadvise(data->dev,
-                            (ext2_loff_t)block * channel->block_size,
+                            (ext2_loff_t)block * channel->block_size + data->offset,
                             (ext2_loff_t)count * channel->block_size,
                             POSIX_FADV_WILLNEED);
 #else
@@ -962,7 +963,7 @@ static errcode_t unix_discard(io_channel channel, unsigned long long block,
 #ifdef BLKDISCARD
                __u64 range[2];
 
-               range[0] = (__u64)(block) * channel->block_size;
+               range[0] = (__u64)(block) * channel->block_size + data->offset;
                range[1] = (__u64)(count) * channel->block_size;
 
                ret = ioctl(data->dev, BLKDISCARD, &range);
@@ -977,7 +978,7 @@ static errcode_t unix_discard(io_channel channel, unsigned long long block,
                 */
                ret = fallocate(data->dev,
                                FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE,
-                               (off_t)(block) * channel->block_size,
+                               (off_t)(block) * channel->block_size + data->offset,
                                (off_t)(count) * channel->block_size);
 #else
                goto unimplemented;
@@ -1025,9 +1026,10 @@ static errcode_t unix_zeroout(io_channel channel, unsigned long long block,
                ret = fstat(data->dev, &statbuf);
                if (ret)
                        goto err;
-               if ((unsigned long long) statbuf.st_size < (block + count) * channel->block_size) {
+               if ((unsigned long long) statbuf.st_size <
+                       (block + count) * channel->block_size + data->offset) {
                        ret = ftruncate(data->dev,
-                                       (block + count) * channel->block_size);
+                                       (block + count) * channel->block_size + data->offset);
                        if (ret)
                                goto err;
                }
@@ -1036,7 +1038,7 @@ static errcode_t unix_zeroout(io_channel channel, unsigned long long block,
 #if defined(FALLOC_FL_PUNCH_HOLE) && defined(FALLOC_FL_KEEP_SIZE)
                ret = fallocate(data->dev,
                                FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE,
-                               (off_t)(block) * channel->block_size,
+                               (off_t)(block) * channel->block_size + data->offset,
                                (off_t)(count) * channel->block_size);
                if (ret == 0)
                        goto err;
@@ -1044,7 +1046,7 @@ static errcode_t unix_zeroout(io_channel channel, unsigned long long block,
 #ifdef FALLOC_FL_ZERO_RANGE
                ret = fallocate(data->dev,
                                FALLOC_FL_ZERO_RANGE,
-                               (off_t)(block) * channel->block_size,
+                               (off_t)(block) * channel->block_size + data->offset,
                                (off_t)(count) * channel->block_size);
 #endif
 #else