/**
* Discard pages protected by the given lock. This function traverses radix
* tree to find all covering pages and discard them. If a page is being covered
* by other locks, it should remain in cache.
*
* If error happens on any step, the process continues anyway (the reasoning
* behind this being that lock cancellation cannot be delayed indefinitely).
*/
static int mdc_lock_discard_pages(const struct lu_env *env,
struct osc_object *osc,
pgoff_t start, pgoff_t end,
bool discard)
{
struct osc_thread_info *info = osc_env_info(env);
struct cl_io *io = &info->oti_io;
osc_page_gang_cbt cb;
int res;
int result;
ENTRY;
io->ci_obj = cl_object_top(osc2cl(osc));
io->ci_ignore_layout = 1;
result = cl_io_init(env, io, CIT_MISC, io->ci_obj);
if (result != 0)
GOTO(out, result);
cb = discard ? osc_discard_cb : mdc_check_and_discard_cb;
info->oti_fn_index = info->oti_next_index = start;
do {
res = osc_page_gang_lookup(env, io, osc, info->oti_next_index,
end, cb, (void *)osc);
if (info->oti_next_index > end)
break;
if (res == CLP_GANG_RESCHED)
cond_resched();
} while (res != CLP_GANG_OKAY);
out:
cl_io_fini(env, io);
RETURN(result);
}
static void osc_trunc_check(const struct lu_env *env, struct cl_io *io,
struct osc_io *oio, __u64 size)
{
struct cl_object *clob;
int partial;
pgoff_t start;
clob = oio->oi_cl.cis_obj;
start = cl_index(clob, size);
partial = cl_offset(clob, start) < size;
/*
* Complain if there are pages in the truncated region.
*/
osc_page_gang_lookup(env, io, cl2osc(clob),
start + partial, CL_PAGE_EOF,
trunc_check_cb, (void *)&size);
}
