exofs: Fix groups code when num_devices is not divisible by group_width

[sfrench/cifs-2.6.git] / fs / exofs / ios.c

diff --git a/fs/exofs/ios.c b/fs/exofs/ios.c
index 4337cad7777b13f98c1d428942387d61a8503c4e..5a1960500c8ad16f40d89841448fbf9f593871b0 100644 (file)
--- a/fs/exofs/ios.c
+++ b/fs/exofs/ios.c
@@ -305,8 +305,6 @@ int exofs_check_io(struct exofs_io_state *ios, u64 *resid)
 struct _striping_info {
        u64 obj_offset;
        u64 group_length;
-       u64 total_group_length;
-       u64 Major;
        unsigned dev;
        unsigned unit_off;
 };
@@ -343,8 +341,6 @@ static void _calc_stripe_info(struct exofs_io_state *ios, u64 file_offset,
                                  (M * group_depth * stripe_unit);
 
        si->group_length = T - H;
-       si->total_group_length = T;
-       si->Major = M;
 }
 
 static int _add_stripe_unit(struct exofs_io_state *ios,  unsigned *cur_pg,
@@ -392,20 +388,19 @@ static int _add_stripe_unit(struct exofs_io_state *ios,  unsigned *cur_pg,
 }
 
 static int _prepare_one_group(struct exofs_io_state *ios, u64 length,
-                             struct _striping_info *si, unsigned first_comp)
+                             struct _striping_info *si)
 {
        unsigned stripe_unit = ios->layout->stripe_unit;
        unsigned mirrors_p1 = ios->layout->mirrors_p1;
        unsigned devs_in_group = ios->layout->group_width * mirrors_p1;
        unsigned dev = si->dev;
        unsigned first_dev = dev - (dev % devs_in_group);
-       unsigned comp = first_comp + (dev - first_dev);
        unsigned max_comp = ios->numdevs ? ios->numdevs - mirrors_p1 : 0;
        unsigned cur_pg = ios->pages_consumed;
        int ret = 0;
 
        while (length) {
-               struct exofs_per_dev_state *per_dev = &ios->per_dev[comp];
+               struct exofs_per_dev_state *per_dev = &ios->per_dev[dev];
                unsigned cur_len, page_off = 0;
 
                if (!per_dev->length) {
@@ -424,11 +419,8 @@ static int _prepare_one_group(struct exofs_io_state *ios, u64 length,
                                cur_len = stripe_unit;
                        }
 
-                       if (max_comp < comp)
-                               max_comp = comp;
-
-                       dev += mirrors_p1;
-                       dev = (dev % devs_in_group) + first_dev;
+                       if (max_comp < dev)
+                               max_comp = dev;
                } else {
                        cur_len = stripe_unit;
                }
@@ -440,8 +432,8 @@ static int _prepare_one_group(struct exofs_io_state *ios, u64 length,
                if (unlikely(ret))
                        goto out;
 
-               comp += mirrors_p1;
-               comp = (comp % devs_in_group) + first_comp;
+               dev += mirrors_p1;
+               dev = (dev % devs_in_group) + first_dev;
 
                length -= cur_len;
        }
@@ -454,18 +446,15 @@ out:
 static int _prepare_for_striping(struct exofs_io_state *ios)
 {
        u64 length = ios->length;
+       u64 offset = ios->offset;
        struct _striping_info si;
-       unsigned devs_in_group = ios->layout->group_width *
-                                ios->layout->mirrors_p1;
-       unsigned first_comp = 0;
        int ret = 0;
 
-       _calc_stripe_info(ios, ios->offset, &si);
-
        if (!ios->pages) {
                if (ios->kern_buff) {
                        struct exofs_per_dev_state *per_dev = &ios->per_dev[0];
 
+                       _calc_stripe_info(ios, ios->offset, &si);
                        per_dev->offset = si.obj_offset;
                        per_dev->dev = si.dev;
 
@@ -479,26 +468,17 @@ static int _prepare_for_striping(struct exofs_io_state *ios)
        }
 
        while (length) {
+               _calc_stripe_info(ios, offset, &si);
+
                if (length < si.group_length)
                        si.group_length = length;
 
-               ret = _prepare_one_group(ios, si.group_length, &si, first_comp);
+               ret = _prepare_one_group(ios, si.group_length, &si);
                if (unlikely(ret))
                        goto out;
 
+               offset += si.group_length;
                length -= si.group_length;
-
-               si.group_length = si.total_group_length;
-               si.unit_off = 0;
-               ++si.Major;
-               si.obj_offset = si.Major * ios->layout->stripe_unit *
-                                               ios->layout->group_depth;
-
-               si.dev = (si.dev - (si.dev % devs_in_group)) + devs_in_group;
-               si.dev %= ios->layout->s_numdevs;
-
-               first_comp += devs_in_group;
-               first_comp %= ios->layout->s_numdevs;
        }
 
 out: