From 681142f9211b23e6aa2984259d38b76d7bdc05a8 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Sat, 21 Nov 2009 20:28:52 +0900 Subject: 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 [hirofumi@mail.parknet.co.jp: tweaks, and add "discard" to fat_show_options] Signed-off-by: OGAWA Hirofumi --- fs/fat/fat.h | 3 ++- fs/fat/fatent.c | 25 +++++++++++++++---------- fs/fat/inode.c | 8 +++++++- 3 files changed, 24 insertions(+), 12 deletions(-) diff --git a/fs/fat/fat.h b/fs/fat/fat.h index 7db0979..e6efdfa 100644 --- a/fs/fat/fat.h +++ b/fs/fat/fat.h @@ -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 diff --git a/fs/fat/fatent.c b/fs/fat/fatent.c index a810377..81184d3 100644 --- a/fs/fat/fatent.c +++ b/fs/fat/fatent.c @@ -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; - - sb_issue_discard(sb, fat_clus_to_blknr(sbi, first_cl), - nr_clus * sbi->sec_per_clus); - first_cl = cluster; + 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; + } } ops->ent_put(&fatent, FAT_ENT_FREE); diff --git a/fs/fat/inode.c b/fs/fat/inode.c index 76b7961..14da530 100644 --- a/fs/fat/inode.c +++ b/fs/fat/inode.c @@ -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: -- cgit v1.1