X-Git-Url: https://pintos-os.org/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=src%2Ffilesys%2Ffile.c;h=e8818c0029383a7d3a0f139963874bf81021dbc2;hb=a4639f9b62f3a2fb38b0c0fc8a1ce34a6d9aa790;hp=d059f379f5cda80173162f07828584d132519e6d;hpb=993c1d9f4452e2edd851f3175dfdf317f18bdb9f;p=pintos-anon diff --git a/src/filesys/file.c b/src/filesys/file.c index d059f37..e8818c0 100644 --- a/src/filesys/file.c +++ b/src/filesys/file.c @@ -45,6 +45,7 @@ file_close (struct file *file) inode_close (file->inode); free (file->bounce); + free (file); } /* Reads SIZE bytes from FILE into BUFFER, @@ -75,7 +76,7 @@ file_read_at (struct file *file, void *buffer_, off_t size, while (size > 0) { /* Disk sector to read, starting byte offset within sector. */ - off_t sector_idx = inode_byte_to_sector (file->inode, file_ofs); + disk_sector_t sector_idx; int sector_ofs = file_ofs % DISK_SECTOR_SIZE; /* Bytes left in file, bytes left in sector, lesser of the two. */ @@ -85,11 +86,12 @@ file_read_at (struct file *file, void *buffer_, off_t size, /* Number of bytes to actually copy out of this sector. */ int chunk_size = size < min_left ? size : min_left; - if (chunk_size == 0) + if (chunk_size <= 0) break; /* Read sector into bounce buffer, then copy into caller's buffer. */ + sector_idx = inode_byte_to_sector (file->inode, file_ofs); disk_read (filesys_disk, sector_idx, file->bounce); memcpy (buffer + bytes_read, file->bounce + sector_ofs, chunk_size); @@ -133,8 +135,8 @@ file_write_at (struct file *file, const void *buffer_, off_t size, while (size > 0) { - /* Starting byte offset within sector to read. */ - off_t sector_idx = inode_byte_to_sector (file->inode, file_ofs); + /* Sector to write, starting byte offset within sector. */ + off_t sector_idx; int sector_ofs = file_ofs % DISK_SECTOR_SIZE; /* Bytes left in file, bytes left in sector, lesser of the two. */ @@ -142,15 +144,16 @@ file_write_at (struct file *file, const void *buffer_, off_t size, int sector_left = DISK_SECTOR_SIZE - sector_ofs; int min_left = file_left < sector_left ? file_left : sector_left; - /* Number of bytes to actually writen into this sector. */ + /* Number of bytes to actually write into this sector. */ int chunk_size = size < min_left ? size : min_left; - if (chunk_size == 0) + if (chunk_size <= 0) break; /* If the sector contains data before or after the chunk we're writing, then we need to read in the sector first. Otherwise we start with a sector of all zeros. */ - if (sector_ofs > 0 || chunk_size < sector_ofs) + sector_idx = inode_byte_to_sector (file->inode, file_ofs); + if (sector_ofs > 0 || chunk_size < sector_left) disk_read (filesys_disk, sector_idx, file->bounce); else memset (file->bounce, 0, DISK_SECTOR_SIZE);