netfs: Refactor arguments for netfs_alloc_read_request

Pass start and len to the rreq allocator. This should ensure that the
fields are set so that ->init_request() can use them.

Also add a parameter to indicates the origin of the request.  Ceph can use
this to tell whether to get caps.

Changes
=======
ver #3)
 - Change the author to me as Jeff feels that most of the patch is my
   changes now.

ver #2)
 - Show the request origin in the netfs_rreq tracepoint.

Signed-off-by: Jeff Layton <jlayton@kernel.org>
Co-developed-by: David Howells <dhowells@redhat.com>
Signed-off-by: David Howells <dhowells@redhat.com>
cc: linux-cachefs@redhat.com

Link: https://lore.kernel.org/r/164622989020.3564931.17517006047854958747.stgit@warthog.procyon.org.uk/
Link: https://lore.kernel.org/r/164678208569.1200972.12153682697842916557.stgit@warthog.procyon.org.uk/
Link: https://lore.kernel.org/r/164692904155.2099075.14717645623034355995.stgit@warthog.procyon.org.uk/

diff --git a/fs/netfs/internal.h b/fs/netfs/internal.h
index a0b7d1b..89837e9 100644 (file)
--- a/fs/netfs/internal.h
+++ b/fs/netfs/internal.h
@@ -17,9 +17,12 @@
 /*
  * objects.c
  */
-struct netfs_io_request *netfs_alloc_request(const struct netfs_request_ops *ops,
+struct netfs_io_request *netfs_alloc_request(struct address_space *mapping,
+                                            struct file *file,
+                                            const struct netfs_request_ops *ops,
                                             void *netfs_priv,
-                                            struct file *file);
+                                            loff_t start, size_t len,
+                                            enum netfs_io_origin origin);
 void netfs_get_request(struct netfs_io_request *rreq, enum netfs_rreq_ref_trace what);
 void netfs_clear_subrequests(struct netfs_io_request *rreq, bool was_async);
 void netfs_put_request(struct netfs_io_request *rreq, bool was_async,

diff --git a/fs/netfs/objects.c b/fs/netfs/objects.c
index 3909789..986d7a9 100644 (file)
--- a/fs/netfs/objects.c
+++ b/fs/netfs/objects.c
@@ -11,17 +11,24 @@
 /*
  * Allocate an I/O request and initialise it.
  */
-struct netfs_io_request *netfs_alloc_request(
-       const struct netfs_request_ops *ops, void *netfs_priv,
-       struct file *file)
+struct netfs_io_request *netfs_alloc_request(struct address_space *mapping,
+                                            struct file *file,
+                                            const struct netfs_request_ops *ops,
+                                            void *netfs_priv,
+                                            loff_t start, size_t len,
+                                            enum netfs_io_origin origin)
 {
        static atomic_t debug_ids;
        struct netfs_io_request *rreq;
 
        rreq = kzalloc(sizeof(struct netfs_io_request), GFP_KERNEL);
        if (rreq) {
+               rreq->start     = start;
+               rreq->len       = len;
+               rreq->origin    = origin;
                rreq->netfs_ops = ops;
                rreq->netfs_priv = netfs_priv;
+               rreq->mapping   = mapping;
                rreq->inode     = file_inode(file);
                rreq->i_size    = i_size_read(rreq->inode);
                rreq->debug_id  = atomic_inc_return(&debug_ids);

diff --git a/fs/netfs/read_helper.c b/fs/netfs/read_helper.c
index 8f277da..dea0857 100644 (file)
--- a/fs/netfs/read_helper.c
+++ b/fs/netfs/read_helper.c
@@ -763,12 +763,13 @@ void netfs_readahead(struct readahead_control *ractl,
        if (readahead_count(ractl) == 0)
                goto cleanup;
 
-       rreq = netfs_alloc_request(ops, netfs_priv, ractl->file);
+       rreq = netfs_alloc_request(ractl->mapping, ractl->file,
+                                  ops, netfs_priv,
+                                  readahead_pos(ractl),
+                                  readahead_length(ractl),
+                                  NETFS_READAHEAD);
        if (!rreq)
                goto cleanup;
-       rreq->mapping   = ractl->mapping;
-       rreq->start     = readahead_pos(ractl);
-       rreq->len       = readahead_length(ractl);
 
        if (ops->begin_cache_operation) {
                ret = ops->begin_cache_operation(rreq);
@@ -838,16 +839,15 @@ int netfs_readpage(struct file *file,
 
        _enter("%lx", folio_index(folio));
 
-       rreq = netfs_alloc_request(ops, netfs_priv, file);
+       rreq = netfs_alloc_request(folio->mapping, file, ops, netfs_priv,
+                                  folio_file_pos(folio), folio_size(folio),
+                                  NETFS_READPAGE);
        if (!rreq) {
                if (netfs_priv)
                        ops->cleanup(folio_file_mapping(folio), netfs_priv);
                folio_unlock(folio);
                return -ENOMEM;
        }
-       rreq->mapping   = folio_file_mapping(folio);
-       rreq->start     = folio_file_pos(folio);
-       rreq->len       = folio_size(folio);
 
        if (ops->begin_cache_operation) {
                ret = ops->begin_cache_operation(rreq);
@@ -1008,12 +1008,11 @@ retry:
        }
 
        ret = -ENOMEM;
-       rreq = netfs_alloc_request(ops, netfs_priv, file);
+       rreq = netfs_alloc_request(mapping, file, ops, netfs_priv,
+                                  folio_file_pos(folio), folio_size(folio),
+                                  NETFS_READ_FOR_WRITE);
        if (!rreq)
                goto error;
-       rreq->mapping           = folio_file_mapping(folio);
-       rreq->start             = folio_file_pos(folio);
-       rreq->len               = folio_size(folio);
        rreq->no_unlock_folio   = folio_index(folio);
        __set_bit(NETFS_RREQ_NO_UNLOCK_FOLIO, &rreq->flags);
        netfs_priv = NULL;

diff --git a/include/linux/netfs.h b/include/linux/netfs.h
index c702bd8..7dc741d 100644 (file)
--- a/include/linux/netfs.h
+++ b/include/linux/netfs.h
@@ -150,6 +150,12 @@ struct netfs_io_subrequest {
 #define NETFS_SREQ_NO_PROGRESS         4       /* Set if we didn't manage to read any data */
 };
 
+enum netfs_io_origin {
+       NETFS_READAHEAD,                /* This read was triggered by readahead */
+       NETFS_READPAGE,                 /* This read is a synchronous read */
+       NETFS_READ_FOR_WRITE,           /* This read is to prepare a write */
+} __mode(byte);
+
 /*
  * Descriptor for an I/O helper request.  This is used to make multiple I/O
  * operations to a variety of data stores and then stitch the result together.
@@ -167,6 +173,7 @@ struct netfs_io_request {
        size_t                  submitted;      /* Amount submitted for I/O so far */
        size_t                  len;            /* Length of the request */
        short                   error;          /* 0 or error that occurred */
+       enum netfs_io_origin    origin;         /* Origin of the request */
        loff_t                  i_size;         /* Size of the file */
        loff_t                  start;          /* Start position */
        pgoff_t                 no_unlock_folio; /* Don't unlock this folio after read */

diff --git a/include/trace/events/netfs.h b/include/trace/events/netfs.h
index 556859b..f00e3e1 100644 (file)
--- a/include/trace/events/netfs.h
+++ b/include/trace/events/netfs.h
@@ -21,6 +21,11 @@
        EM(netfs_read_trace_readpage,           "READPAGE ")    \
        E_(netfs_read_trace_write_begin,        "WRITEBEGN")
 
+#define netfs_rreq_origins                                     \
+       EM(NETFS_READAHEAD,                     "RA")           \
+       EM(NETFS_READPAGE,                      "RP")           \
+       E_(NETFS_READ_FOR_WRITE,                "RW")
+
 #define netfs_rreq_traces                                      \
        EM(netfs_rreq_trace_assess,             "ASSESS ")      \
        EM(netfs_rreq_trace_copy,               "COPY   ")      \
@@ -101,6 +106,7 @@ enum netfs_sreq_ref_trace { netfs_sreq_ref_traces } __mode(byte);
 #define E_(a, b) TRACE_DEFINE_ENUM(a);
 
 netfs_read_traces;
+netfs_rreq_origins;
 netfs_rreq_traces;
 netfs_sreq_sources;
 netfs_sreq_traces;
@@ -159,17 +165,20 @@ TRACE_EVENT(netfs_rreq,
            TP_STRUCT__entry(
                    __field(unsigned int,               rreq            )
                    __field(unsigned int,               flags           )
+                   __field(enum netfs_io_origin,       origin          )
                    __field(enum netfs_rreq_trace,      what            )
                             ),
 
            TP_fast_assign(
                    __entry->rreq       = rreq->debug_id;
                    __entry->flags      = rreq->flags;
+                   __entry->origin     = rreq->origin;
                    __entry->what       = what;
                           ),
 
-           TP_printk("R=%08x %s f=%02x",
+           TP_printk("R=%08x %s %s f=%02x",
                      __entry->rreq,
+                     __print_symbolic(__entry->origin, netfs_rreq_origins),
                      __print_symbolic(__entry->what, netfs_rreq_traces),
                      __entry->flags)
            );