From 8669247524c73e16e4d3384c4ff882e5c5d06194 Mon Sep 17 00:00:00 2001 From: Jingbo Xu Date: Thu, 24 Nov 2022 11:42:11 +0800 Subject: fscache,cachefiles: add prepare_ondemand_read() callback Add prepare_ondemand_read() callback dedicated for the on-demand read scenario, so that callers from this scenario can be decoupled from netfs_io_subrequest. The original cachefiles_prepare_read() is now refactored to a generic routine accepting a parameter list instead of netfs_io_subrequest. There's no logic change, except that the debug id of subrequest and request is removed from trace_cachefiles_prep_read(). Reviewed-by: Jeff Layton Signed-off-by: Jingbo Xu Acked-by: David Howells Link: https://lore.kernel.org/r/20221124034212.81892-2-jefflexu@linux.alibaba.com Signed-off-by: Gao Xiang --- fs/cachefiles/io.c | 77 +++++++++++++++++++++++++++++++++++------------------- 1 file changed, 50 insertions(+), 27 deletions(-) (limited to 'fs/cachefiles/io.c') diff --git a/fs/cachefiles/io.c b/fs/cachefiles/io.c index 000a28f46e59..175a25fcade8 100644 --- a/fs/cachefiles/io.c +++ b/fs/cachefiles/io.c @@ -385,38 +385,35 @@ static int cachefiles_write(struct netfs_cache_resources *cres, term_func, term_func_priv); } -/* - * Prepare a read operation, shortening it to a cached/uncached - * boundary as appropriate. - */ -static enum netfs_io_source cachefiles_prepare_read(struct netfs_io_subrequest *subreq, - loff_t i_size) +static inline enum netfs_io_source +cachefiles_do_prepare_read(struct netfs_cache_resources *cres, + loff_t start, size_t *_len, loff_t i_size, + unsigned long *_flags, ino_t netfs_ino) { enum cachefiles_prepare_read_trace why; - struct netfs_io_request *rreq = subreq->rreq; - struct netfs_cache_resources *cres = &rreq->cache_resources; - struct cachefiles_object *object; + struct cachefiles_object *object = NULL; struct cachefiles_cache *cache; struct fscache_cookie *cookie = fscache_cres_cookie(cres); const struct cred *saved_cred; struct file *file = cachefiles_cres_file(cres); enum netfs_io_source ret = NETFS_DOWNLOAD_FROM_SERVER; + size_t len = *_len; loff_t off, to; ino_t ino = file ? file_inode(file)->i_ino : 0; int rc; - _enter("%zx @%llx/%llx", subreq->len, subreq->start, i_size); + _enter("%zx @%llx/%llx", len, start, i_size); - if (subreq->start >= i_size) { + if (start >= i_size) { ret = NETFS_FILL_WITH_ZEROES; why = cachefiles_trace_read_after_eof; goto out_no_object; } if (test_bit(FSCACHE_COOKIE_NO_DATA_TO_READ, &cookie->flags)) { - __set_bit(NETFS_SREQ_COPY_TO_CACHE, &subreq->flags); + __set_bit(NETFS_SREQ_COPY_TO_CACHE, _flags); why = cachefiles_trace_read_no_data; - if (!test_bit(NETFS_SREQ_ONDEMAND, &subreq->flags)) + if (!test_bit(NETFS_SREQ_ONDEMAND, _flags)) goto out_no_object; } @@ -437,7 +434,7 @@ static enum netfs_io_source cachefiles_prepare_read(struct netfs_io_subrequest * retry: off = cachefiles_inject_read_error(); if (off == 0) - off = vfs_llseek(file, subreq->start, SEEK_DATA); + off = vfs_llseek(file, start, SEEK_DATA); if (off < 0 && off >= (loff_t)-MAX_ERRNO) { if (off == (loff_t)-ENXIO) { why = cachefiles_trace_read_seek_nxio; @@ -449,21 +446,22 @@ retry: goto out; } - if (off >= subreq->start + subreq->len) { + if (off >= start + len) { why = cachefiles_trace_read_found_hole; goto download_and_store; } - if (off > subreq->start) { + if (off > start) { off = round_up(off, cache->bsize); - subreq->len = off - subreq->start; + len = off - start; + *_len = len; why = cachefiles_trace_read_found_part; goto download_and_store; } to = cachefiles_inject_read_error(); if (to == 0) - to = vfs_llseek(file, subreq->start, SEEK_HOLE); + to = vfs_llseek(file, start, SEEK_HOLE); if (to < 0 && to >= (loff_t)-MAX_ERRNO) { trace_cachefiles_io_error(object, file_inode(file), to, cachefiles_trace_seek_error); @@ -471,12 +469,13 @@ retry: goto out; } - if (to < subreq->start + subreq->len) { - if (subreq->start + subreq->len >= i_size) + if (to < start + len) { + if (start + len >= i_size) to = round_up(to, cache->bsize); else to = round_down(to, cache->bsize); - subreq->len = to - subreq->start; + len = to - start; + *_len = len; } why = cachefiles_trace_read_have_data; @@ -484,12 +483,11 @@ retry: goto out; download_and_store: - __set_bit(NETFS_SREQ_COPY_TO_CACHE, &subreq->flags); - if (test_bit(NETFS_SREQ_ONDEMAND, &subreq->flags)) { - rc = cachefiles_ondemand_read(object, subreq->start, - subreq->len); + __set_bit(NETFS_SREQ_COPY_TO_CACHE, _flags); + if (test_bit(NETFS_SREQ_ONDEMAND, _flags)) { + rc = cachefiles_ondemand_read(object, start, len); if (!rc) { - __clear_bit(NETFS_SREQ_ONDEMAND, &subreq->flags); + __clear_bit(NETFS_SREQ_ONDEMAND, _flags); goto retry; } ret = NETFS_INVALID_READ; @@ -497,10 +495,34 @@ download_and_store: out: cachefiles_end_secure(cache, saved_cred); out_no_object: - trace_cachefiles_prep_read(subreq, ret, why, ino); + trace_cachefiles_prep_read(object, start, len, *_flags, ret, why, ino, netfs_ino); return ret; } +/* + * Prepare a read operation, shortening it to a cached/uncached + * boundary as appropriate. + */ +static enum netfs_io_source cachefiles_prepare_read(struct netfs_io_subrequest *subreq, + loff_t i_size) +{ + return cachefiles_do_prepare_read(&subreq->rreq->cache_resources, + subreq->start, &subreq->len, i_size, + &subreq->flags, subreq->rreq->inode->i_ino); +} + +/* + * Prepare an on-demand read operation, shortening it to a cached/uncached + * boundary as appropriate. + */ +static enum netfs_io_source +cachefiles_prepare_ondemand_read(struct netfs_cache_resources *cres, + loff_t start, size_t *_len, loff_t i_size, + unsigned long *_flags, ino_t ino) +{ + return cachefiles_do_prepare_read(cres, start, _len, i_size, _flags, ino); +} + /* * Prepare for a write to occur. */ @@ -621,6 +643,7 @@ static const struct netfs_cache_ops cachefiles_netfs_cache_ops = { .write = cachefiles_write, .prepare_read = cachefiles_prepare_read, .prepare_write = cachefiles_prepare_write, + .prepare_ondemand_read = cachefiles_prepare_ondemand_read, .query_occupancy = cachefiles_query_occupancy, }; -- cgit v1.2.3-70-g09d2