From 402cb8dda949d9b8c0df20ad2527d139faad7ca1 Mon Sep 17 00:00:00 2001 From: David Howells Date: Wed, 4 Apr 2018 13:41:28 +0100 Subject: fscache: Attach the index key and aux data to the cookie Attach copies of the index key and auxiliary data to the fscache cookie so that: (1) The callbacks to the netfs for this stuff can be eliminated. This can simplify things in the cache as the information is still available, even after the cache has relinquished the cookie. (2) Simplifies the locking requirements of accessing the information as we don't have to worry about the netfs object going away on us. (3) The cache can do lazy updating of the coherency information on disk. As long as the cache is flushed before reboot/poweroff, there's no need to update the coherency info on disk every time it changes. (4) Cookies can be hashed or put in a tree as the index key is easily available. This allows: (a) Checks for duplicate cookies can be made at the top fscache layer rather than down in the bowels of the cache backend. (b) Caching can be added to a netfs object that has a cookie if the cache is brought online after the netfs object is allocated. A certain amount of space is made in the cookie for inline copies of the data, but if it won't fit there, extra memory will be allocated for it. The downside of this is that live cache operation requires more memory. Signed-off-by: David Howells Acked-by: Anna Schumaker Tested-by: Steve Dickson --- fs/fscache/object-list.c | 28 +++++++++++++--------------- 1 file changed, 13 insertions(+), 15 deletions(-) (limited to 'fs/fscache/object-list.c') diff --git a/fs/fscache/object-list.c b/fs/fscache/object-list.c index 0438d4cd91ef..43e6e28c164f 100644 --- a/fs/fscache/object-list.c +++ b/fs/fscache/object-list.c @@ -36,8 +36,6 @@ struct fscache_objlist_data { #define FSCACHE_OBJLIST_CONFIG_NOEVENTS 0x00000800 /* show objects without no events */ #define FSCACHE_OBJLIST_CONFIG_WORK 0x00001000 /* show objects with work */ #define FSCACHE_OBJLIST_CONFIG_NOWORK 0x00002000 /* show objects without work */ - - u8 buf[512]; /* key and aux data buffer */ }; /* @@ -170,7 +168,7 @@ static int fscache_objlist_show(struct seq_file *m, void *v) struct fscache_cookie *cookie; unsigned long config = data->config; char _type[3], *type; - u8 *buf = data->buf, *p; + u8 *p; if ((unsigned long) v == 1) { seq_puts(m, "OBJECT PARENT STAT CHLDN OPS OOP IPR EX READS" @@ -254,7 +252,7 @@ static int fscache_objlist_show(struct seq_file *m, void *v) if (fscache_use_cookie(obj)) { uint16_t keylen = 0, auxlen = 0; - switch (cookie->def->type) { + switch (cookie->type) { case 0: type = "IX"; break; @@ -263,7 +261,7 @@ static int fscache_objlist_show(struct seq_file *m, void *v) break; default: snprintf(_type, sizeof(_type), "%02u", - cookie->def->type); + cookie->type); type = _type; break; } @@ -274,30 +272,30 @@ static int fscache_objlist_show(struct seq_file *m, void *v) cookie->flags, cookie->netfs_data); - if (cookie->def->get_key && - config & FSCACHE_OBJLIST_CONFIG_KEY) - keylen = cookie->def->get_key(cookie->netfs_data, - buf, 400); + if (config & FSCACHE_OBJLIST_CONFIG_KEY) + keylen = cookie->key_len; - if (cookie->def->get_aux && - config & FSCACHE_OBJLIST_CONFIG_AUX) - auxlen = cookie->def->get_aux(cookie->netfs_data, - buf + keylen, 512 - keylen); - fscache_unuse_cookie(obj); + if (config & FSCACHE_OBJLIST_CONFIG_AUX) + auxlen = cookie->aux_len; if (keylen > 0 || auxlen > 0) { seq_puts(m, " "); - for (p = buf; keylen > 0; keylen--) + p = keylen <= sizeof(cookie->inline_key) ? + cookie->inline_key : cookie->key; + for (; keylen > 0; keylen--) seq_printf(m, "%02x", *p++); if (auxlen > 0) { if (config & FSCACHE_OBJLIST_CONFIG_KEY) seq_puts(m, ", "); + p = auxlen <= sizeof(cookie->inline_aux) ? + cookie->inline_aux : cookie->aux; for (; auxlen > 0; auxlen--) seq_printf(m, "%02x", *p++); } } seq_puts(m, "\n"); + fscache_unuse_cookie(obj); } else { seq_puts(m, "\n"); } -- cgit v1.2.3