UBIFS: pre-allocate bulk-read buffer
To avoid memory allocation failure during bulk-read, pre-allocate
a bulk-read buffer, so that if there is only one bulk-reader at
a time, it would just use the pre-allocated buffer and would not
do any memory allocation. However, if there are more than 1 bulk-
reader, then only one reader would use the pre-allocated buffer,
while the other reader would allocate the buffer for itself.
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
diff --git a/fs/ubifs/super.c b/fs/ubifs/super.c
index 1d51156..d80b2aef 100644
--- a/fs/ubifs/super.c
+++ b/fs/ubifs/super.c
@@ -572,14 +572,6 @@
c->max_bu_buf_len = UBIFS_MAX_BULK_READ * UBIFS_MAX_DATA_NODE_SZ;
if (c->max_bu_buf_len > c->leb_size)
c->max_bu_buf_len = c->leb_size;
- if (c->max_bu_buf_len > UBIFS_KMALLOC_OK) {
- /* Check if we can kmalloc that much */
- void *try = kmalloc(c->max_bu_buf_len,
- GFP_KERNEL | __GFP_NOWARN);
- kfree(try);
- if (!try)
- c->max_bu_buf_len = UBIFS_KMALLOC_OK;
- }
return 0;
}
@@ -999,6 +991,34 @@
}
/**
+ * bu_init - initialize bulk-read information.
+ * @c: UBIFS file-system description object
+ */
+static void bu_init(struct ubifs_info *c)
+{
+ ubifs_assert(c->bulk_read == 1);
+
+ if (c->bu.buf)
+ return; /* Already initialized */
+
+again:
+ c->bu.buf = kmalloc(c->max_bu_buf_len, GFP_KERNEL | __GFP_NOWARN);
+ if (!c->bu.buf) {
+ if (c->max_bu_buf_len > UBIFS_KMALLOC_OK) {
+ c->max_bu_buf_len = UBIFS_KMALLOC_OK;
+ goto again;
+ }
+
+ /* Just disable bulk-read */
+ ubifs_warn("Cannot allocate %d bytes of memory for bulk-read, "
+ "disabling it", c->max_bu_buf_len);
+ c->mount_opts.bulk_read = 1;
+ c->bulk_read = 0;
+ return;
+ }
+}
+
+/**
* mount_ubifs - mount UBIFS file-system.
* @c: UBIFS file-system description object
*
@@ -1066,6 +1086,13 @@
goto out_free;
}
+ if (c->bulk_read == 1)
+ bu_init(c);
+
+ /*
+ * We have to check all CRCs, even for data nodes, when we mount the FS
+ * (specifically, when we are replaying).
+ */
c->always_chk_crc = 1;
err = ubifs_read_superblock(c);
@@ -1296,6 +1323,7 @@
out_dereg:
dbg_failure_mode_deregistration(c);
out_free:
+ kfree(c->bu.buf);
vfree(c->ileb_buf);
vfree(c->sbuf);
kfree(c->bottom_up_buf);
@@ -1332,10 +1360,11 @@
kfree(c->cbuf);
kfree(c->rcvrd_mst_node);
kfree(c->mst_node);
+ kfree(c->bu.buf);
+ vfree(c->ileb_buf);
vfree(c->sbuf);
kfree(c->bottom_up_buf);
UBIFS_DBG(vfree(c->dbg_buf));
- vfree(c->ileb_buf);
dbg_failure_mode_deregistration(c);
}
@@ -1633,6 +1662,7 @@
ubifs_err("invalid or unknown remount parameter");
return err;
}
+
if ((sb->s_flags & MS_RDONLY) && !(*flags & MS_RDONLY)) {
err = ubifs_remount_rw(c);
if (err)
@@ -1640,6 +1670,14 @@
} else if (!(sb->s_flags & MS_RDONLY) && (*flags & MS_RDONLY))
ubifs_remount_ro(c);
+ if (c->bulk_read == 1)
+ bu_init(c);
+ else {
+ dbg_gen("disable bulk-read");
+ kfree(c->bu.buf);
+ c->bu.buf = NULL;
+ }
+
return 0;
}
@@ -1730,6 +1768,7 @@
mutex_init(&c->log_mutex);
mutex_init(&c->mst_mutex);
mutex_init(&c->umount_mutex);
+ mutex_init(&c->bu_mutex);
init_waitqueue_head(&c->cmt_wq);
c->buds = RB_ROOT;
c->old_idx = RB_ROOT;