xref: /minix3/minix/fs/mfs/stadir.c (revision 03ac74ede908465cc64c671bbd209e761dc765dc)
1 #include "fs.h"
2 #include <string.h>
3 #include <sys/stat.h>
4 #include <sys/statvfs.h>
5 #include "inode.h"
6 #include "super.h"
7 
8 /*===========================================================================*
9  *				estimate_blocks				     *
10  *===========================================================================*/
11 static blkcnt_t estimate_blocks(struct inode *rip)
12 {
13 /* Return the number of 512-byte blocks used by this file. This includes space
14  * used by data zones and indirect blocks (actually also zones). Reading in all
15  * indirect blocks is too costly for a stat call, so we disregard holes and
16  * return a conservative estimation.
17  */
18   blkcnt_t zones, sindirs, dindirs, nr_indirs, sq_indirs;
19   unsigned int zone_size;
20 
21   /* Compute the number of zones used by the file. */
22   zone_size = rip->i_sp->s_block_size << rip->i_sp->s_log_zone_size;
23 
24   zones = (blkcnt_t) ((rip->i_size + zone_size - 1) / zone_size);
25 
26   /* Compute the number of indirect blocks needed for that zone count. */
27   nr_indirs = (blkcnt_t) rip->i_nindirs;
28   sq_indirs = nr_indirs * nr_indirs;
29 
30   sindirs = (zones - (blkcnt_t) rip->i_ndzones + nr_indirs - 1) / nr_indirs;
31   dindirs = (sindirs - 1 + sq_indirs - 1) / sq_indirs;
32 
33   /* Return the number of 512-byte blocks corresponding to the number of data
34    * zones and indirect blocks.
35    */
36   return (zones + sindirs + dindirs) * (blkcnt_t) (zone_size / 512);
37 }
38 
39 
40 /*===========================================================================*
41  *                             fs_stat					     *
42  *===========================================================================*/
43 int fs_stat(ino_t ino_nr, struct stat *statbuf)
44 {
45   struct inode *rip;
46   mode_t mo;
47   int s;
48 
49   if ((rip = get_inode(fs_dev, ino_nr)) == NULL)
50 	return(EINVAL);
51 
52   /* Update the atime, ctime, and mtime fields in the inode, if need be. */
53   if (rip->i_update) update_times(rip);
54 
55   /* Fill in the statbuf struct. */
56   mo = rip->i_mode & I_TYPE;
57 
58   /* true iff special */
59   s = (mo == I_CHAR_SPECIAL || mo == I_BLOCK_SPECIAL);
60 
61   statbuf->st_mode = (mode_t) rip->i_mode;
62   statbuf->st_nlink = (nlink_t) rip->i_nlinks;
63   statbuf->st_uid = rip->i_uid;
64   statbuf->st_gid = rip->i_gid;
65   statbuf->st_rdev = (s ? (dev_t)rip->i_zone[0] : NO_DEV);
66   statbuf->st_size = rip->i_size;
67   statbuf->st_atime = rip->i_atime;
68   statbuf->st_mtime = rip->i_mtime;
69   statbuf->st_ctime = rip->i_ctime;
70   statbuf->st_blksize = lmfs_fs_block_size();
71   statbuf->st_blocks = estimate_blocks(rip);
72 
73   put_inode(rip);		/* release the inode */
74 
75   return(OK);
76 }
77 
78 
79 /*===========================================================================*
80  *				fs_statvfs				     *
81  *===========================================================================*/
82 int fs_statvfs(struct statvfs *st)
83 {
84   struct super_block *sp;
85   int scale;
86 
87   sp = &superblock;
88 
89   scale = sp->s_log_zone_size;
90 
91   st->f_blocks = sp->s_zones;
92   st->f_bfree = sp->s_zones - used_zones;
93   st->f_bavail = st->f_bfree;
94 
95   st->f_bsize = sp->s_block_size << scale;
96   st->f_frsize = sp->s_block_size;
97   st->f_iosize = st->f_frsize;
98   st->f_files = sp->s_ninodes;
99   st->f_ffree = count_free_bits(sp, IMAP);
100   st->f_favail = st->f_ffree;
101   st->f_namemax = MFS_DIRSIZ;
102 
103   return(OK);
104 }
105