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 * BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
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 * BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
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 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE
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 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE
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 * OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
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 * OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
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 * EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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 * EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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 */
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 */
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/** @addtogroup FileSystemImpl
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* @{
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/* This file contains the heart of the mechanism used to read files.
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 * Read requests are split up into chunks that do not cross block
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 * boundaries. Each chunk is then processed in turn.
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 */
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*/
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/**
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/* Methods:
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 * @file    read.c
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 * do_read:    perform the READ system call
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 * @brief   This file contains the heart of the mechanism used to read files.
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 * read_map:   given an inode and file position, look up its zone number
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 *        Read requests are split up into chunks that do not cross block
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 * rd_indir:   read an entry in an indirect block
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 *        boundaries. Each chunk is then processed in turn.
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 */
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 */
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#include <stdio.h>
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#include <stdio.h>
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#include "fs.h"
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#include "fs.h"
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#include "block.h"
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#include "block.h"
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static int read_chunk(inode_t *rip, offset_t position,
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static int read_chunk(inode_t *rip, offset_t position,
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        unsigned off, int chunk, char *buff);
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        unsigned off, int chunk, char *buff);
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/**
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 * Perform the READ system call
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 */
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int do_read()
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int do_read()
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{
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{
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    /* Perform read(fd, buffer, nbytes) call. */
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    /* Perform read(fd, buffer, nbytes) call. */
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    else {
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    else {
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        print_console("Some error occured during reading the file\n");
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        print_console("Some error occured during reading the file\n");
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        return r;
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        return r;
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    }
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    }
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}
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}
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/**
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 * Given an inode and file position, look up its zone number
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 */
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static int read_chunk(register inode_t *rip, offset_t position, unsigned off,
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static int read_chunk(register inode_t *rip, offset_t position, unsigned off,
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    int chunk, char *buff)
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    int chunk, char *buff)
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{
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{
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    /*
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    /*
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    /* Copy a chunk from the block buffer to user space. */
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    /* Copy a chunk from the block buffer to user space. */
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    memcpy((void *)buff, (void *)(bp->b.b__data+off), chunk);
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    memcpy((void *)buff, (void *)(bp->b.b__data+off), chunk);
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    return OK;
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    return OK;
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}
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}
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/**
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 * Read an entry in an indirect block
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 */
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block_num_t read_map(register inode_t *rip, offset_t position)
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block_num_t read_map(register inode_t *rip, offset_t position)
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{
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{
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    /* Given an inode and a position within the corresponding file, locate the
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    /* Given an inode and a position within the corresponding file, locate the
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     * block (not zone) number in which that position is to be found and return it.
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     * block (not zone) number in which that position is to be found and return it.
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    b = ((block_num_t) z << scale) + boff;
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    b = ((block_num_t) z << scale) + boff;
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    return b;
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    return b;
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}
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}
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/**
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 *
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 */
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zone_t rd_indir(block_t *bp, int index)
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zone_t rd_indir(block_t *bp, int index)
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{
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{
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    super_block_t *sp;
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    super_block_t *sp;
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    zone_t zone;   
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    zone_t zone;   
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    }
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    }
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    return zone;
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    return zone;
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}
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}
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/**
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 * }
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 */
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