xref: /minix/minix/fs/mfs/stadir.c (revision 9f988b79)
1 #include "fs.h"
2 #include <string.h>
3 #include <assert.h>
4 #include <sys/stat.h>
5 #include <sys/statvfs.h>
6 #include "inode.h"
7 #include "super.h"
8 
9 /*===========================================================================*
10  *				estimate_blocks				     *
11  *===========================================================================*/
12 static blkcnt_t estimate_blocks(struct inode *rip)
13 {
14 /* Return the number of 512-byte blocks used by this file. This includes space
15  * used by data zones and indirect blocks (actually also zones). Reading in all
16  * indirect blocks is too costly for a stat call, so we disregard holes and
17  * return a conservative estimation.
18  */
19   blkcnt_t zones, sindirs, dindirs, nr_indirs, sq_indirs;
20   unsigned int zone_size;
21 
22   /* Compute the number of zones used by the file. */
23   zone_size = rip->i_sp->s_block_size << rip->i_sp->s_log_zone_size;
24 
25   zones = (blkcnt_t) ((rip->i_size + zone_size - 1) / zone_size);
26 
27   /* Compute the number of indirect blocks needed for that zone count. */
28   nr_indirs = (blkcnt_t) rip->i_nindirs;
29   sq_indirs = nr_indirs * nr_indirs;
30 
31   sindirs = (zones - (blkcnt_t) rip->i_ndzones + nr_indirs - 1) / nr_indirs;
32   dindirs = (sindirs - 1 + sq_indirs - 1) / sq_indirs;
33 
34   /* Return the number of 512-byte blocks corresponding to the number of data
35    * zones and indirect blocks.
36    */
37   return (zones + sindirs + dindirs) * (blkcnt_t) (zone_size / 512);
38 }
39 
40 
41 /*===========================================================================*
42  *                             fs_stat					     *
43  *===========================================================================*/
44 int fs_stat(ino_t ino_nr, struct stat *statbuf)
45 {
46   struct inode *rip;
47   mode_t mo;
48   int s;
49 
50   if ((rip = get_inode(fs_dev, ino_nr)) == NULL)
51 	return(EINVAL);
52 
53   /* Update the atime, ctime, and mtime fields in the inode, if need be. */
54   if (rip->i_update) update_times(rip);
55 
56   /* Fill in the statbuf struct. */
57   mo = rip->i_mode & I_TYPE;
58 
59   /* true iff special */
60   s = (mo == I_CHAR_SPECIAL || mo == I_BLOCK_SPECIAL);
61 
62   statbuf->st_mode = (mode_t) rip->i_mode;
63   statbuf->st_nlink = (nlink_t) rip->i_nlinks;
64   statbuf->st_uid = rip->i_uid;
65   statbuf->st_gid = rip->i_gid;
66   statbuf->st_rdev = (s ? (dev_t)rip->i_zone[0] : NO_DEV);
67   statbuf->st_size = rip->i_size;
68   statbuf->st_atime = rip->i_atime;
69   statbuf->st_mtime = rip->i_mtime;
70   statbuf->st_ctime = rip->i_ctime;
71   statbuf->st_blksize = lmfs_fs_block_size();
72   statbuf->st_blocks = estimate_blocks(rip);
73 
74   put_inode(rip);		/* release the inode */
75 
76   return(OK);
77 }
78 
79 
80 /*===========================================================================*
81  *				fs_statvfs				     *
82  *===========================================================================*/
83 int fs_statvfs(struct statvfs *st)
84 {
85   struct super_block *sp;
86   int scale;
87 
88   sp = &superblock;
89 
90   scale = sp->s_log_zone_size;
91 
92   st->f_blocks = sp->s_zones;
93   st->f_bfree = sp->s_zones - used_zones;
94   st->f_bavail = st->f_bfree;
95 
96   st->f_bsize = sp->s_block_size << scale;
97   st->f_frsize = sp->s_block_size;
98   st->f_iosize = st->f_frsize;
99   st->f_files = sp->s_ninodes;
100   st->f_ffree = count_free_bits(sp, IMAP);
101   st->f_favail = st->f_ffree;
102   st->f_namemax = MFS_DIRSIZ;
103 
104   return(OK);
105 }
106