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authorDavid Howells <dhowells@redhat.com>2021-10-21 08:50:10 +0100
committerDavid Howells <dhowells@redhat.com>2022-01-07 13:42:50 +0000
commit7623ed6772de31cadcc474b87bcbc1db84cc1e8e (patch)
tree4e2223ef6977324805b51b98e23fdbf64f04aa60 /fs/cachefiles
parent287fd611238dd4b7e32fd3a8985aa387d26c4f29 (diff)
cachefiles: Implement cookie resize for truncate
Implement resizing an object, using truncate and/or fallocate to adjust the object. Signed-off-by: David Howells <dhowells@redhat.com> Reviewed-by: Jeff Layton <jlayton@kernel.org> cc: linux-cachefs@redhat.com Link: https://lore.kernel.org/r/163819646631.215744.13819016478175576761.stgit@warthog.procyon.org.uk/ # v1 Link: https://lore.kernel.org/r/163906952877.143852.4140962906331914859.stgit@warthog.procyon.org.uk/ # v2 Link: https://lore.kernel.org/r/163967162168.1823006.5941985259926902274.stgit@warthog.procyon.org.uk/ # v3 Link: https://lore.kernel.org/r/164021560394.640689.9972155785508094960.stgit@warthog.procyon.org.uk/ # v4
Diffstat (limited to 'fs/cachefiles')
-rw-r--r--fs/cachefiles/interface.c78
1 files changed, 78 insertions, 0 deletions
diff --git a/fs/cachefiles/interface.c b/fs/cachefiles/interface.c
index ad9d311413ff..51c968cd00a6 100644
--- a/fs/cachefiles/interface.c
+++ b/fs/cachefiles/interface.c
@@ -221,6 +221,83 @@ fail:
}
/*
+ * Shorten the backing object to discard any dirty data and free up
+ * any unused granules.
+ */
+static bool cachefiles_shorten_object(struct cachefiles_object *object,
+ struct file *file, loff_t new_size)
+{
+ struct cachefiles_cache *cache = object->volume->cache;
+ struct inode *inode = file_inode(file);
+ loff_t i_size, dio_size;
+ int ret;
+
+ dio_size = round_up(new_size, CACHEFILES_DIO_BLOCK_SIZE);
+ i_size = i_size_read(inode);
+
+ trace_cachefiles_trunc(object, inode, i_size, dio_size,
+ cachefiles_trunc_shrink);
+ ret = cachefiles_inject_remove_error();
+ if (ret == 0)
+ ret = vfs_truncate(&file->f_path, dio_size);
+ if (ret < 0) {
+ trace_cachefiles_io_error(object, file_inode(file), ret,
+ cachefiles_trace_trunc_error);
+ cachefiles_io_error_obj(object, "Trunc-to-size failed %d", ret);
+ cachefiles_remove_object_xattr(cache, object, file->f_path.dentry);
+ return false;
+ }
+
+ if (new_size < dio_size) {
+ trace_cachefiles_trunc(object, inode, dio_size, new_size,
+ cachefiles_trunc_dio_adjust);
+ ret = cachefiles_inject_write_error();
+ if (ret == 0)
+ ret = vfs_fallocate(file, FALLOC_FL_ZERO_RANGE,
+ new_size, dio_size);
+ if (ret < 0) {
+ trace_cachefiles_io_error(object, file_inode(file), ret,
+ cachefiles_trace_fallocate_error);
+ cachefiles_io_error_obj(object, "Trunc-to-dio-size failed %d", ret);
+ cachefiles_remove_object_xattr(cache, object, file->f_path.dentry);
+ return false;
+ }
+ }
+
+ return true;
+}
+
+/*
+ * Resize the backing object.
+ */
+static void cachefiles_resize_cookie(struct netfs_cache_resources *cres,
+ loff_t new_size)
+{
+ struct cachefiles_object *object = cachefiles_cres_object(cres);
+ struct cachefiles_cache *cache = object->volume->cache;
+ struct fscache_cookie *cookie = object->cookie;
+ const struct cred *saved_cred;
+ struct file *file = cachefiles_cres_file(cres);
+ loff_t old_size = cookie->object_size;
+
+ _enter("%llu->%llu", old_size, new_size);
+
+ if (new_size < old_size) {
+ cachefiles_begin_secure(cache, &saved_cred);
+ cachefiles_shorten_object(object, file, new_size);
+ cachefiles_end_secure(cache, saved_cred);
+ object->cookie->object_size = new_size;
+ return;
+ }
+
+ /* The file is being expanded. We don't need to do anything
+ * particularly. cookie->initial_size doesn't change and so the point
+ * at which we have to download before doesn't change.
+ */
+ cookie->object_size = new_size;
+}
+
+/*
* Commit changes to the object as we drop it.
*/
static void cachefiles_commit_object(struct cachefiles_object *object,
@@ -363,5 +440,6 @@ const struct fscache_cache_ops cachefiles_cache_ops = {
.withdraw_cookie = cachefiles_withdraw_cookie,
.invalidate_cookie = cachefiles_invalidate_cookie,
.begin_operation = cachefiles_begin_operation,
+ .resize_cookie = cachefiles_resize_cookie,
.prepare_to_write = cachefiles_prepare_to_write,
};