fs/jfs/jfs_discard.c

   1 /*
   2  *   Copyright (C) Tino Reichardt, 2012
   3  *
   4  *   This program is free software;  you can redistribute it and/or modify
   5  *   it under the terms of the GNU General Public License as published by
   6  *   the Free Software Foundation; either version 2 of the License, or
   7  *   (at your option) any later version.
   8  *
   9  *   This program is distributed in the hope that it will be useful,
  10  *   but WITHOUT ANY WARRANTY;  without even the implied warranty of
  11  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See
  12  *   the GNU General Public License for more details.
  13  *
  14  *   You should have received a copy of the GNU General Public License
  15  *   along with this program;  if not, write to the Free Software
  16  *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  17  */
  18
  19 #include <linux/fs.h>
  20 #include <linux/slab.h>
  21 #include <linux/blkdev.h>
  22
  23 #include "jfs_incore.h"
  24 #include "jfs_superblock.h"
  25 #include "jfs_discard.h"
  26 #include "jfs_dmap.h"
  27 #include "jfs_debug.h"
  28
  29
  30 /*
  31  * NAME:        jfs_issue_discard()
  32  *
  33  * FUNCTION:    TRIM the specified block range on device, if supported
  34  *
  35  * PARAMETERS:
  36  *      ip      - pointer to in-core inode
  37  *      blkno   - starting block number to be trimmed (0..N)
  38  *      nblocks - number of blocks to be trimmed
  39  *
  40  * RETURN VALUES:
  41  *      none
  42  *
  43  * serialization: IREAD_LOCK(ipbmap) held on entry/exit;
  44  */
  45 void jfs_issue_discard(struct inode *ip, u64 blkno, u64 nblocks)
  46 {
  47         struct super_block *sb = ip->i_sb;
  48         int r = 0;
  49
  50         r = sb_issue_discard(sb, blkno, nblocks, GFP_NOFS, 0);
  51         if (unlikely(r != 0)) {
  52                 jfs_err("JFS: sb_issue_discard(%p, %llu, %llu, GFP_NOFS, 0) = %d => failed!",
  53                         sb, (unsigned long long)blkno,
  54                         (unsigned long long)nblocks, r);
  55         }
  56
  57         jfs_info("JFS: sb_issue_discard(%p, %llu, %llu, GFP_NOFS, 0) = %d",
  58                 sb, (unsigned long long)blkno,
  59                 (unsigned long long)nblocks, r);
  60
  61         return;
  62 }
  63
  64 /*
  65  * NAME:        jfs_ioc_trim()
  66  *
  67  * FUNCTION:    attempt to discard (TRIM) all free blocks from the
  68  *              filesystem.
  69  *
  70  * PARAMETERS:
  71  *      ip      - pointer to in-core inode;
  72  *      range   - the range, given by user space
  73  *
  74  * RETURN VALUES:
  75  *      0       - success
  76  *      -EIO    - i/o error
  77  */
  78 int jfs_ioc_trim(struct inode *ip, struct fstrim_range *range)
  79 {
  80         struct inode *ipbmap = JFS_SBI(ip->i_sb)->ipbmap;
  81         struct bmap *bmp = JFS_SBI(ip->i_sb)->bmap;
  82         struct super_block *sb = ipbmap->i_sb;
  83         int agno, agno_end;
  84         u64 start, end, minlen;
  85         u64 trimmed = 0;
  86
  87         /**
  88          * convert byte values to block size of filesystem:
  89          * start:       First Byte to trim
  90          * len:         number of Bytes to trim from start
  91          * minlen:      minimum extent length in Bytes
  92          */
  93         start = range->start >> sb->s_blocksize_bits;
  94         end = start + (range->len >> sb->s_blocksize_bits) - 1;
  95         minlen = range->minlen >> sb->s_blocksize_bits;
  96         if (minlen == 0)
  97                 minlen = 1;
  98
  99         if (minlen > bmp->db_agsize ||
 100             start >= bmp->db_mapsize ||
 101             range->len < sb->s_blocksize)
 102                 return -EINVAL;
 103
 104         if (end >= bmp->db_mapsize)
 105                 end = bmp->db_mapsize - 1;
 106
 107         /**
 108          * we trim all ag's within the range
 109          */
 110         agno = BLKTOAG(start, JFS_SBI(ip->i_sb));
 111         agno_end = BLKTOAG(end, JFS_SBI(ip->i_sb));
 112         while (agno <= agno_end) {
 113                 trimmed += dbDiscardAG(ip, agno, minlen);
 114                 agno++;
 115         }
 116         range->len = trimmed << sb->s_blocksize_bits;
 117
 118         return 0;
 119 }