1 #include "fs.h"
2 #include "inode.h"
3 #include "super.h"
4 #include <minix/vfsif.h>
5 #include <minix/bdev.h>
6
7 /*===========================================================================*
8 * fs_mount *
9 *===========================================================================*/
fs_mount(dev_t dev,unsigned int flags,struct fsdriver_node * root_node,unsigned int * res_flags)10 int fs_mount(dev_t dev, unsigned int flags, struct fsdriver_node *root_node,
11 unsigned int *res_flags)
12 {
13 /* This function reads the superblock of the partition, gets the root inode
14 * and sends back the details of them.
15 */
16 struct inode *root_ip;
17 int r, readonly;
18
19 fs_dev = dev;
20 readonly = (flags & REQ_RDONLY) ? 1 : 0;
21
22 /* Open the device the file system lives on. */
23 if (bdev_open(fs_dev, readonly ? BDEV_R_BIT : (BDEV_R_BIT|BDEV_W_BIT) ) !=
24 OK) {
25 return(EINVAL);
26 }
27
28 /* Fill in the super block. */
29 superblock.s_dev = fs_dev; /* read_super() needs to know which dev */
30 r = read_super(&superblock);
31
32 /* Is it recognized as a Minix filesystem? */
33 if (r != OK) {
34 superblock.s_dev = NO_DEV;
35 bdev_close(fs_dev);
36 return(r);
37 }
38
39 /* clean check: if rw and not clean, switch to readonly */
40 if(!(superblock.s_flags & MFSFLAG_CLEAN) && !readonly) {
41 if(bdev_close(fs_dev) != OK)
42 panic("couldn't bdev_close after found unclean FS");
43 readonly = 1;
44
45 if (bdev_open(fs_dev, BDEV_R_BIT) != OK) {
46 panic("couldn't bdev_open after found unclean FS");
47 return(EINVAL);
48 }
49 printf("MFS: WARNING: FS 0x%llx unclean, mounting readonly\n", fs_dev);
50 }
51
52 lmfs_set_blocksize(superblock.s_block_size);
53
54 /* Compute the current number of used zones, and report it to libminixfs.
55 * Note that libminixfs really wants numbers of *blocks*, but this MFS
56 * implementation dropped support for differing zone/block sizes a while ago.
57 */
58 used_zones = superblock.s_zones - count_free_bits(&superblock, ZMAP);
59
60 lmfs_set_blockusage(superblock.s_zones, used_zones);
61
62 /* Get the root inode of the mounted file system. */
63 if( (root_ip = get_inode(fs_dev, ROOT_INODE)) == NULL) {
64 printf("MFS: couldn't get root inode\n");
65 superblock.s_dev = NO_DEV;
66 bdev_close(fs_dev);
67 return(EINVAL);
68 }
69
70 if(root_ip->i_mode == 0) {
71 printf("%s:%d zero mode for root inode?\n", __FILE__, __LINE__);
72 put_inode(root_ip);
73 superblock.s_dev = NO_DEV;
74 bdev_close(fs_dev);
75 return(EINVAL);
76 }
77
78 superblock.s_rd_only = readonly;
79
80 /* Root inode properties */
81 root_node->fn_ino_nr = root_ip->i_num;
82 root_node->fn_mode = root_ip->i_mode;
83 root_node->fn_size = root_ip->i_size;
84 root_node->fn_uid = root_ip->i_uid;
85 root_node->fn_gid = root_ip->i_gid;
86 root_node->fn_dev = NO_DEV;
87
88 *res_flags = RES_NOFLAGS;
89
90 /* Mark it dirty */
91 if(!superblock.s_rd_only) {
92 superblock.s_flags &= ~MFSFLAG_CLEAN;
93 if(write_super(&superblock) != OK)
94 panic("mounting: couldn't write dirty superblock");
95 }
96
97 return(r);
98 }
99
100
101 /*===========================================================================*
102 * fs_mountpt *
103 *===========================================================================*/
fs_mountpt(ino_t ino_nr)104 int fs_mountpt(ino_t ino_nr)
105 {
106 /* This function looks up the mount point, it checks the condition whether
107 * the partition can be mounted on the inode or not.
108 */
109 register struct inode *rip;
110 int r = OK;
111 mode_t bits;
112
113 /* Temporarily open the file. */
114 if( (rip = get_inode(fs_dev, ino_nr)) == NULL)
115 return(EINVAL);
116
117 if(rip->i_mountpoint) r = EBUSY;
118
119 /* It may not be special. */
120 bits = rip->i_mode & I_TYPE;
121 if (bits == I_BLOCK_SPECIAL || bits == I_CHAR_SPECIAL) r = ENOTDIR;
122
123 put_inode(rip);
124
125 if(r == OK) rip->i_mountpoint = TRUE;
126
127 return(r);
128 }
129
130
131 /*===========================================================================*
132 * fs_unmount *
133 *===========================================================================*/
fs_unmount(void)134 void fs_unmount(void)
135 {
136 /* Unmount a file system. */
137 int count;
138 struct inode *rip, *root_ip;
139
140 /* See if the mounted device is busy. Only 1 inode using it should be
141 * open --the root inode-- and that inode only 1 time. This is an integrity
142 * check only: VFS expects the unmount to succeed either way.
143 */
144 count = 0;
145 for (rip = &inode[0]; rip < &inode[NR_INODES]; rip++)
146 if (rip->i_count > 0 && rip->i_dev == fs_dev) count += rip->i_count;
147 if (count != 1)
148 printf("MFS: file system has %d in-use inodes!\n", count);
149
150 if ((root_ip = find_inode(fs_dev, ROOT_INODE)) == NULL)
151 panic("MFS: couldn't find root inode\n");
152
153 put_inode(root_ip);
154
155 /* force any cached blocks out of memory */
156 fs_sync();
157
158 /* Mark it clean if we're allowed to write _and_ it was clean originally. */
159 if (!superblock.s_rd_only) {
160 superblock.s_flags |= MFSFLAG_CLEAN;
161 write_super(&superblock);
162 }
163
164 /* Close the device the file system lives on. */
165 bdev_close(fs_dev);
166
167 /* Throw out blocks out of the VM cache, to prevent corruption later. */
168 lmfs_invalidate(fs_dev);
169
170 /* Finish off the unmount. */
171 superblock.s_dev = NO_DEV;
172 }
173
174