fat: make discard a mount option

Currently shipping discard capable SSDs and arrays have rather sub-optimal
implementations of the command and can the use of it can cause massive
slowdowns.  Make issueing these commands option as it's already in btrfs
and gfs2.

Signed-off-by: Christoph Hellwig <hch@lst.de>
[hirofumi@mail.parknet.co.jp: tweaks, and add "discard" to fat_show_options]
Signed-off-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
This commit is contained in:
Christoph Hellwig 2009-11-21 20:28:52 +09:00 committed by OGAWA Hirofumi
parent a8a8a669ea
commit 681142f921
3 changed files with 23 additions and 11 deletions

View file

@ -44,7 +44,8 @@ struct fat_mount_options {
nocase:1, /* Does this need case conversion? 0=need case conversion*/
usefree:1, /* Use free_clusters for FAT32 */
tz_utc:1, /* Filesystem timestamps are in UTC */
rodir:1; /* allow ATTR_RO for directory */
rodir:1, /* allow ATTR_RO for directory */
discard:1; /* Issue discard requests on deletions */
};
#define FAT_HASH_BITS 8

View file

@ -566,16 +566,21 @@ int fat_free_clusters(struct inode *inode, int cluster)
goto error;
}
/*
* Issue discard for the sectors we no longer care about,
* batching contiguous clusters into one request
*/
if (cluster != fatent.entry + 1) {
int nr_clus = fatent.entry - first_cl + 1;
if (sbi->options.discard) {
/*
* Issue discard for the sectors we no longer
* care about, batching contiguous clusters
* into one request
*/
if (cluster != fatent.entry + 1) {
int nr_clus = fatent.entry - first_cl + 1;
sb_issue_discard(sb, fat_clus_to_blknr(sbi, first_cl),
nr_clus * sbi->sec_per_clus);
first_cl = cluster;
sb_issue_discard(sb,
fat_clus_to_blknr(sbi, first_cl),
nr_clus * sbi->sec_per_clus);
first_cl = cluster;
}
}
ops->ent_put(&fatent, FAT_ENT_FREE);

View file

@ -858,6 +858,8 @@ static int fat_show_options(struct seq_file *m, struct vfsmount *mnt)
seq_puts(m, ",errors=panic");
else
seq_puts(m, ",errors=remount-ro");
if (opts->discard)
seq_puts(m, ",discard");
return 0;
}
@ -871,7 +873,7 @@ enum {
Opt_shortname_winnt, Opt_shortname_mixed, Opt_utf8_no, Opt_utf8_yes,
Opt_uni_xl_no, Opt_uni_xl_yes, Opt_nonumtail_no, Opt_nonumtail_yes,
Opt_obsolate, Opt_flush, Opt_tz_utc, Opt_rodir, Opt_err_cont,
Opt_err_panic, Opt_err_ro, Opt_err,
Opt_err_panic, Opt_err_ro, Opt_discard, Opt_err,
};
static const match_table_t fat_tokens = {
@ -899,6 +901,7 @@ static const match_table_t fat_tokens = {
{Opt_err_cont, "errors=continue"},
{Opt_err_panic, "errors=panic"},
{Opt_err_ro, "errors=remount-ro"},
{Opt_discard, "discard"},
{Opt_obsolate, "conv=binary"},
{Opt_obsolate, "conv=text"},
{Opt_obsolate, "conv=auto"},
@ -1136,6 +1139,9 @@ static int parse_options(char *options, int is_vfat, int silent, int *debug,
case Opt_rodir:
opts->rodir = 1;
break;
case Opt_discard:
opts->discard = 1;
break;
/* obsolete mount options */
case Opt_obsolate: