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authorPhilipp Stanner <pstanner@redhat.com>2023-08-21 10:21:29 +0200
committerMatthew Wilcox (Oracle) <willy@infradead.org>2023-09-05 19:01:38 -0400
commite7716c74e3882405f9eca16faa6cb1bf19995399 (patch)
tree13fcc03b9751bd875fb3c67ac1002118a27d1566 /lib/xarray.c
parentcbc02854331edc6dc22d8b77b6e22e38ebc7dd51 (diff)
downloadlwn-e7716c74e3882405f9eca16faa6cb1bf19995399.tar.gz
lwn-e7716c74e3882405f9eca16faa6cb1bf19995399.zip
xarray: Document necessary flag in alloc functions
Adds a new line to the docstrings of functions wrapping __xa_alloc() and __xa_alloc_cyclic(), informing about the necessity of flag XA_FLAGS_ALLOC being set previously. The documentation so far says that functions wrapping __xa_alloc() and __xa_alloc_cyclic() are supposed to return either -ENOMEM or -EBUSY in case of an error. If the xarray has been initialized without the flag XA_FLAGS_ALLOC, however, they fail with a different, undocumented error code. As hinted at in Documentation/core-api/xarray.rst, wrappers around these functions should only be invoked when the flag has been set. The functions' documentation should reflect that as well. Signed-off-by: Philipp Stanner <pstanner@redhat.com> Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Diffstat (limited to 'lib/xarray.c')
-rw-r--r--lib/xarray.c6
1 files changed, 6 insertions, 0 deletions
diff --git a/lib/xarray.c b/lib/xarray.c
index 142e36f9dfda..39f07bfc4dcc 100644
--- a/lib/xarray.c
+++ b/lib/xarray.c
@@ -1802,6 +1802,9 @@ EXPORT_SYMBOL(xa_get_order);
* stores the index into the @id pointer, then stores the entry at
* that index. A concurrent lookup will not see an uninitialised @id.
*
+ * Must only be operated on an xarray initialized with flag XA_FLAGS_ALLOC set
+ * in xa_init_flags().
+ *
* Context: Any context. Expects xa_lock to be held on entry. May
* release and reacquire xa_lock if @gfp flags permit.
* Return: 0 on success, -ENOMEM if memory could not be allocated or
@@ -1850,6 +1853,9 @@ EXPORT_SYMBOL(__xa_alloc);
* The search for an empty entry will start at @next and will wrap
* around if necessary.
*
+ * Must only be operated on an xarray initialized with flag XA_FLAGS_ALLOC set
+ * in xa_init_flags().
+ *
* Context: Any context. Expects xa_lock to be held on entry. May
* release and reacquire xa_lock if @gfp flags permit.
* Return: 0 if the allocation succeeded without wrapping. 1 if the