LU-12142 clio: fix hang on urgent cached pages

[fs/lustre-release.git] / lustre / llite / file.c

diff --git a/lustre/llite/file.c b/lustre/llite/file.c
index 76350c0..e0a902a 100644 (file)
--- a/lustre/llite/file.c
+++ b/lustre/llite/file.c
@@ -1542,6 +1542,7 @@ ll_file_io_generic(const struct lu_env *env, struct vvp_io_args *args,
        struct vvp_io *vio = vvp_env_io(env);
        struct inode *inode = file_inode(file);
        struct ll_inode_info *lli = ll_i2info(inode);
+       struct ll_sb_info *sbi = ll_i2sbi(inode);
        struct ll_file_data *fd  = file->private_data;
        struct range_lock range;
        struct cl_io *io;
@@ -1550,6 +1551,9 @@ ll_file_io_generic(const struct lu_env *env, struct vvp_io_args *args,
        unsigned int retried = 0, dio_lock = 0;
        bool is_aio = false;
        struct cl_dio_aio *ci_aio = NULL;
+       size_t per_bytes;
+       bool partial_io = false;
+       size_t max_io_pages, max_cached_pages;
 
        ENTRY;
 
@@ -1557,6 +1561,11 @@ ll_file_io_generic(const struct lu_env *env, struct vvp_io_args *args,
                file_dentry(file)->d_name.name,
                iot == CIT_READ ? "read" : "write", *ppos, count);
 
+       max_io_pages = PTLRPC_MAX_BRW_PAGES * OBD_MAX_RIF_DEFAULT;
+       max_cached_pages = sbi->ll_cache->ccc_lru_max;
+       if (max_io_pages > (max_cached_pages >> 2))
+               max_io_pages = max_cached_pages >> 2;
+
        io = vvp_env_thread_io(env);
        if (file->f_flags & O_DIRECT) {
                if (!is_sync_kiocb(args->u.normal.via_iocb))
@@ -1567,19 +1576,29 @@ ll_file_io_generic(const struct lu_env *env, struct vvp_io_args *args,
        }
 
 restart:
+       /**
+        * IO block size need be aware of cached page limit, otherwise
+        * if we have small max_cached_mb but large block IO issued, io
+        * could not be finished and blocked whole client.
+        */
+       if (file->f_flags & O_DIRECT)
+               per_bytes = count;
+       else
+               per_bytes = min(max_io_pages << PAGE_SHIFT, count);
+       partial_io = per_bytes < count;
        io = vvp_env_thread_io(env);
        ll_io_init(io, file, iot, args);
        io->ci_aio = ci_aio;
        io->ci_dio_lock = dio_lock;
        io->ci_ndelay_tried = retried;
 
-       if (cl_io_rw_init(env, io, iot, *ppos, count) == 0) {
+       if (cl_io_rw_init(env, io, iot, *ppos, per_bytes) == 0) {
                bool range_locked = false;
 
                if (file->f_flags & O_APPEND)
                        range_lock_init(&range, 0, LUSTRE_EOF);
                else
-                       range_lock_init(&range, *ppos, *ppos + count - 1);
+                       range_lock_init(&range, *ppos, *ppos + per_bytes - 1);
 
                vio->vui_fd  = file->private_data;
                vio->vui_iter = args->u.normal.via_iter;
@@ -1631,6 +1650,16 @@ restart:
                /* prepare IO restart */
                if (count > 0)
                        args->u.normal.via_iter = vio->vui_iter;
+
+               if (partial_io) {
+                       /**
+                        * Reexpand iov count because it was zero
+                        * after IO finish.
+                        */
+                       iov_iter_reexpand(vio->vui_iter, count);
+                       if (per_bytes == io->ci_nob)
+                               io->ci_need_restart = 1;
+               }
        }
 out:
        cl_io_fini(env, io);