Change the request initialisation function to return an error code so that
the network filesystem can return a failure (ENOMEM, for example).
This will also allow ceph to abort a ->readahead() op if the server refuses
to give it a cap allowing local caching from within the netfslib framework
(errors aren't passed back through ->readahead(), so returning, say,
-ENOBUFS will cause the op to be aborted).
Signed-off-by: David Howells <dhowells@xxxxxxxxxx>
cc: linux-cachefs@xxxxxxxxxx
---
fs/9p/vfs_addr.c | 3 ++-
fs/afs/file.c | 3 ++-
fs/netfs/objects.c | 41 ++++++++++++++++++++++++-----------------
fs/netfs/read_helper.c | 20 ++++++++++++--------
include/linux/netfs.h | 2 +-
5 files changed, 41 insertions(+), 28 deletions(-)
diff --git a/fs/9p/vfs_addr.c b/fs/9p/vfs_addr.c
index fdc1033a1546..91d3926c9559 100644
--- a/fs/9p/vfs_addr.c
+++ b/fs/9p/vfs_addr.c
@@ -56,12 +56,13 @@ static void v9fs_issue_read(struct netfs_io_subrequest *subreq)
* @rreq: The read request
* @file: The file being read from
*/
-static void v9fs_init_request(struct netfs_io_request *rreq, struct file *file)
+static int v9fs_init_request(struct netfs_io_request *rreq, struct file *file)
{
struct p9_fid *fid = file->private_data;
refcount_inc(&fid->count);
rreq->netfs_priv = fid;
+ return 0;
}
/**
diff --git a/fs/afs/file.c b/fs/afs/file.c
index b19d635eed12..6469d7f98ef5 100644
--- a/fs/afs/file.c
+++ b/fs/afs/file.c
@@ -359,9 +359,10 @@ static int afs_symlink_readpage(struct file *file, struct page *page)
return ret;
}
-static void afs_init_request(struct netfs_io_request *rreq, struct file *file)
+static int afs_init_request(struct netfs_io_request *rreq, struct file *file)
{
rreq->netfs_priv = key_get(afs_file_key(file));
+ return 0;
}
static bool afs_is_cache_enabled(struct inode *inode)
diff --git a/fs/netfs/objects.c b/fs/netfs/objects.c
index 986d7a9d25dd..ae18827e156b 100644
--- a/fs/netfs/objects.c
+++ b/fs/netfs/objects.c
@@ -20,27 +20,34 @@ struct netfs_io_request *netfs_alloc_request(struct address_space *mapping,
{
static atomic_t debug_ids;
struct netfs_io_request *rreq;
+ int ret;
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);
- INIT_LIST_HEAD(&rreq->subrequests);
- INIT_WORK(&rreq->work, netfs_rreq_work);
- refcount_set(&rreq->ref, 1);
- __set_bit(NETFS_RREQ_IN_PROGRESS, &rreq->flags);
- if (ops->init_request)
- ops->init_request(rreq, file);
- netfs_stat(&netfs_n_rh_rreq);
+ if (!rreq)
+ return ERR_PTR(-ENOMEM);
+
+ 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);
+ INIT_LIST_HEAD(&rreq->subrequests);
+ INIT_WORK(&rreq->work, netfs_rreq_work);
+ refcount_set(&rreq->ref, 1);
+ __set_bit(NETFS_RREQ_IN_PROGRESS, &rreq->flags);
+ if (rreq->netfs_ops->init_request) {
+ ret = rreq->netfs_ops->init_request(rreq, file);
+ if (ret < 0) {
+ kfree(rreq);
+ return ERR_PTR(ret);
+ }
}
+ netfs_stat(&netfs_n_rh_rreq);
return rreq;
}
diff --git a/fs/netfs/read_helper.c b/fs/netfs/read_helper.c
index dea085715286..b5176f4320f4 100644
--- a/fs/netfs/read_helper.c
+++ b/fs/netfs/read_helper.c
@@ -768,7 +768,7 @@ void netfs_readahead(struct readahead_control *ractl,
readahead_pos(ractl),
readahead_length(ractl),
NETFS_READAHEAD);
- if (!rreq)
+ if (IS_ERR(rreq))
goto cleanup;
if (ops->begin_cache_operation) {
@@ -842,11 +842,9 @@ int netfs_readpage(struct file *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;
+ if (IS_ERR(rreq)) {
+ ret = PTR_ERR(rreq);
+ goto alloc_error;
}
if (ops->begin_cache_operation) {
@@ -887,6 +885,11 @@ int netfs_readpage(struct file *file,
out:
netfs_put_request(rreq, false, netfs_rreq_trace_put_hold);
return ret;
+alloc_error:
+ if (netfs_priv)
+ ops->cleanup(folio_file_mapping(folio), netfs_priv);
+ folio_unlock(folio);
+ return ret;
}
EXPORT_SYMBOL(netfs_readpage);
@@ -1007,12 +1010,13 @@ int netfs_write_begin(struct file *file, struct address_space *mapping,
goto have_folio_no_wait;
}
- ret = -ENOMEM;
rreq = netfs_alloc_request(mapping, file, ops, netfs_priv,
folio_file_pos(folio), folio_size(folio),
NETFS_READ_FOR_WRITE);
- if (!rreq)
+ if (IS_ERR(rreq)) {
+ ret = PTR_ERR(rreq);
goto error;
+ }
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 7dc741d9b21b..4b99e38f73d9 100644
--- a/include/linux/netfs.h
+++ b/include/linux/netfs.h
@@ -193,7 +193,7 @@ struct netfs_io_request {
*/
struct netfs_request_ops {
bool (*is_cache_enabled)(struct inode *inode);
- void (*init_request)(struct netfs_io_request *rreq, struct file *file);
+ int (*init_request)(struct netfs_io_request *rreq, struct file *file);
int (*begin_cache_operation)(struct netfs_io_request *rreq);
void (*expand_readahead)(struct netfs_io_request *rreq);
bool (*clamp_length)(struct netfs_io_subrequest *subreq);
--
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