1 /* This file contains file metadata retrieval and manipulation routines. 2 * 3 * The entry points into this file are: 4 * get_mode return a file's mode 5 * do_stat perform the STAT file system call 6 * do_chmod perform the CHMOD file system call 7 * do_utime perform the UTIME file system call 8 * 9 * Created: 10 * April 2009 (D.C. van Moolenbroek) 11 */ 12 13 #include "inc.h" 14 15 /*===========================================================================* 16 * get_mode * 17 *===========================================================================*/ 18 mode_t get_mode(struct inode *ino, int mode) 19 { 20 /* Return the mode for an inode, given the inode and the retrieved mode. 21 */ 22 23 mode &= S_IRWXU; 24 mode = mode | (mode >> 3) | (mode >> 6); 25 26 if (IS_DIR(ino)) 27 mode = S_IFDIR | (mode & sffs_params->p_dir_mask); 28 else 29 mode = S_IFREG | (mode & sffs_params->p_file_mask); 30 31 if (read_only) 32 mode &= ~(S_IWUSR | S_IWGRP | S_IWOTH); 33 34 return mode; 35 } 36 37 /*===========================================================================* 38 * do_stat * 39 *===========================================================================*/ 40 int do_stat(ino_t ino_nr, struct stat *st) 41 { 42 /* Retrieve inode status. 43 */ 44 struct inode *ino; 45 struct sffs_attr attr; 46 char path[PATH_MAX]; 47 int r; 48 49 /* Don't increase the inode refcount: it's already open anyway */ 50 if ((ino = find_inode(ino_nr)) == NULL) 51 return EINVAL; 52 53 attr.a_mask = SFFS_ATTR_MODE | SFFS_ATTR_SIZE | SFFS_ATTR_CRTIME | 54 SFFS_ATTR_ATIME | SFFS_ATTR_MTIME | SFFS_ATTR_CTIME; 55 56 if ((r = verify_inode(ino, path, &attr)) != OK) 57 return r; 58 59 st->st_mode = get_mode(ino, attr.a_mode); 60 st->st_uid = sffs_params->p_uid; 61 st->st_gid = sffs_params->p_gid; 62 st->st_rdev = NO_DEV; 63 st->st_size = attr.a_size; 64 st->st_atimespec = attr.a_atime; 65 st->st_mtimespec = attr.a_mtime; 66 st->st_ctimespec = attr.a_ctime; 67 st->st_birthtimespec = attr.a_crtime; 68 69 st->st_blocks = st->st_size / S_BLKSIZE; 70 if (st->st_size % S_BLKSIZE != 0) 71 st->st_blocks += 1; 72 73 st->st_blksize = BLOCK_SIZE; 74 75 /* We could make this more accurate by iterating over directory inodes' 76 * children, counting how many of those are directories as well. 77 * It's just not worth it. 78 */ 79 st->st_nlink = 0; 80 if (ino->i_parent != NULL) st->st_nlink++; 81 if (IS_DIR(ino)) { 82 st->st_nlink++; 83 if (HAS_CHILDREN(ino)) st->st_nlink++; 84 } 85 86 return OK; 87 } 88 89 /*===========================================================================* 90 * do_chmod * 91 *===========================================================================*/ 92 int do_chmod(ino_t ino_nr, mode_t *mode) 93 { 94 /* Change file mode. 95 */ 96 struct inode *ino; 97 char path[PATH_MAX]; 98 struct sffs_attr attr; 99 int r; 100 101 if (read_only) 102 return EROFS; 103 104 if ((ino = find_inode(ino_nr)) == NULL) 105 return EINVAL; 106 107 if ((r = verify_inode(ino, path, NULL)) != OK) 108 return r; 109 110 /* Set the new file mode. */ 111 attr.a_mask = SFFS_ATTR_MODE; 112 attr.a_mode = *mode; /* no need to convert in this direction */ 113 114 if ((r = sffs_table->t_setattr(path, &attr)) != OK) 115 return r; 116 117 /* We have no idea what really happened. Query for the mode again. */ 118 if ((r = verify_path(path, ino, &attr, NULL)) != OK) 119 return r; 120 121 *mode = get_mode(ino, attr.a_mode); 122 123 return OK; 124 } 125 126 /*===========================================================================* 127 * do_utime * 128 *===========================================================================*/ 129 int do_utime(ino_t ino_nr, struct timespec *atime, struct timespec *mtime) 130 { 131 /* Set file times. 132 */ 133 struct inode *ino; 134 char path[PATH_MAX]; 135 struct sffs_attr attr; 136 int r; 137 138 if (read_only) 139 return EROFS; 140 141 if ((ino = find_inode(ino_nr)) == NULL) 142 return EINVAL; 143 144 if ((r = verify_inode(ino, path, NULL)) != OK) 145 return r; 146 147 attr.a_mask = 0; 148 149 switch (atime->tv_nsec) { 150 case UTIME_OMIT: /* do not touch */ 151 break; 152 case UTIME_NOW: 153 /* XXX VFS should have time() into ACTIME, for compat; we trust it! */ 154 atime->tv_nsec = 0; 155 /*FALLTHROUGH*/ 156 default: 157 attr.a_atime = *atime; 158 attr.a_mask |= SFFS_ATTR_ATIME; 159 break; 160 } 161 162 switch (mtime->tv_nsec) { 163 case UTIME_OMIT: /* do not touch */ 164 break; 165 case UTIME_NOW: 166 /* XXX VFS should have time() into MODTIME, for compat; we trust it! */ 167 mtime->tv_nsec = 0; 168 /*FALLTHROUGH*/ 169 default: 170 attr.a_mtime = *mtime; 171 attr.a_mask |= SFFS_ATTR_MTIME; 172 break; 173 } 174 175 return sffs_table->t_setattr(path, &attr); 176 } 177