bcachefs: Assorted fixes for running on very small devices

It's now possible to create and use a filesystem on a 512k device with
4k buckets (though at that size we still waste almost half to internal
reserves)

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

diff --git a/fs/bcachefs/alloc_background.c b/fs/bcachefs/alloc_background.c
index 1eb39283e7e2c08ac95734efd8731545e96db75a..a4c4a08aed5984c11bd3f7cb93eb35c03b568338 100644 (file)
--- a/fs/bcachefs/alloc_background.c
+++ b/fs/bcachefs/alloc_background.c
@@ -374,6 +374,11 @@ static void bch2_rescale_bucket_io_times(struct bch_fs *c, int rw)
        }
 }
 
+static inline u64 bucket_clock_freq(u64 capacity)
+{
+       return max(capacity >> 10, 2028ULL);
+}
+
 static void bch2_inc_clock_hand(struct io_timer *timer)
 {
        struct bucket_clock *clock = container_of(timer,
@@ -412,7 +417,7 @@ static void bch2_inc_clock_hand(struct io_timer *timer)
         * RW mode (that will be 0 when we're RO, yet we can still service
         * reads)
         */
-       timer->expire += capacity >> 10;
+       timer->expire += bucket_clock_freq(capacity);
 
        bch2_io_timer_add(&c->io_clock[clock->rw], timer);
 }
@@ -424,7 +429,7 @@ static void bch2_bucket_clock_init(struct bch_fs *c, int rw)
        clock->hand             = 1;
        clock->rw               = rw;
        clock->rescale.fn       = bch2_inc_clock_hand;
-       clock->rescale.expire   = c->capacity >> 10;
+       clock->rescale.expire   = bucket_clock_freq(c->capacity);
        mutex_init(&clock->lock);
 }
 
@@ -1011,8 +1016,6 @@ void bch2_recalc_capacity(struct bch_fs *c)
                for (j = 0; j < RESERVE_NONE; j++)
                        dev_reserve += ca->free[j].size;
 
-               dev_reserve += ca->free_inc.size;
-
                dev_reserve += 1;       /* btree write point */
                dev_reserve += 1;       /* copygc write point */
                dev_reserve += 1;       /* rebalance write point */

diff --git a/fs/bcachefs/alloc_background.h b/fs/bcachefs/alloc_background.h
index 245e037fbaea8e4f426c2ba2142410236284cd4b..33224070e8272234cd93fbb6f617f6b1213bd2ee 100644 (file)
--- a/fs/bcachefs/alloc_background.h
+++ b/fs/bcachefs/alloc_background.h
@@ -6,7 +6,7 @@
 #include "alloc_types.h"
 #include "debug.h"
 
-#define ALLOC_SCAN_BATCH(ca)           ((ca)->mi.nbuckets >> 9)
+#define ALLOC_SCAN_BATCH(ca)           max_t(size_t, 1, (ca)->mi.nbuckets >> 9)
 
 const char *bch2_alloc_invalid(const struct bch_fs *, struct bkey_s_c);
 int bch2_alloc_to_text(struct bch_fs *, char *, size_t, struct bkey_s_c);

diff --git a/fs/bcachefs/bcachefs.h b/fs/bcachefs/bcachefs.h
index 5665b93f200b75ef855ed62778ccb9305ca9f691..22df84b78f4bff7eb1e85efc07ba7a3bdc9b6c2d 100644 (file)
--- a/fs/bcachefs/bcachefs.h
+++ b/fs/bcachefs/bcachefs.h
@@ -325,7 +325,7 @@ enum bch_time_stats {
 #define BTREE_RESERVE_MAX      (BTREE_MAX_DEPTH + (BTREE_MAX_DEPTH - 1))
 
 /* Size of the freelist we allocate btree nodes from: */
-#define BTREE_NODE_RESERVE     (BTREE_RESERVE_MAX * 4)
+#define BTREE_NODE_RESERVE     BTREE_RESERVE_MAX
 
 struct btree;
 

diff --git a/fs/bcachefs/bcachefs_format.h b/fs/bcachefs/bcachefs_format.h
index 46355f006793a63f1e6dd65181b81f6803a762c8..d74f1e5c21e0e722b6dfa9e07c311fe11d59271e 100644 (file)
--- a/fs/bcachefs/bcachefs_format.h
+++ b/fs/bcachefs/bcachefs_format.h
@@ -909,6 +909,8 @@ struct bch_sb_field_journal {
 
 /* BCH_SB_FIELD_members: */
 
+#define BCH_MIN_NR_NBUCKETS    (1 << 6)
+
 struct bch_member {
        __uuid_t                uuid;
        __le64                  nbuckets;       /* device size */
@@ -1391,7 +1393,7 @@ struct jset {
 LE32_BITMASK(JSET_CSUM_TYPE,   struct jset, flags, 0, 4);
 LE32_BITMASK(JSET_BIG_ENDIAN,  struct jset, flags, 4, 5);
 
-#define BCH_JOURNAL_BUCKETS_MIN                20
+#define BCH_JOURNAL_BUCKETS_MIN                8
 
 /* Btree: */
 

diff --git a/fs/bcachefs/buckets.c b/fs/bcachefs/buckets.c
index cfbe3ed41d0e0da67f75366c23b5baed28e51ab0..28ec8a58319ca4f00b99523160132e5e1551dfce 100644 (file)
--- a/fs/bcachefs/buckets.c
+++ b/fs/bcachefs/buckets.c
@@ -887,9 +887,9 @@ int bch2_dev_buckets_resize(struct bch_fs *c, struct bch_dev *ca, u64 nbuckets)
        size_t btree_reserve    = DIV_ROUND_UP(BTREE_NODE_RESERVE,
                             ca->mi.bucket_size / c->opts.btree_node_size);
        /* XXX: these should be tunable */
-       size_t reserve_none     = max_t(size_t, 4, nbuckets >> 9);
-       size_t copygc_reserve   = max_t(size_t, 16, nbuckets >> 7);
-       size_t free_inc_nr      = max(max_t(size_t, 16, nbuckets >> 12),
+       size_t reserve_none     = max_t(size_t, 1, nbuckets >> 9);
+       size_t copygc_reserve   = max_t(size_t, 2, nbuckets >> 7);
+       size_t free_inc_nr      = max(max_t(size_t, 1, nbuckets >> 12),
                                      btree_reserve);
        bool resize = ca->buckets != NULL,
             start_copygc = ca->copygc_thread != NULL;

diff --git a/fs/bcachefs/recovery.c b/fs/bcachefs/recovery.c
index e21551e8d6cc5b04e066b42bef2b89738978b894..696e01f4962f63de541f22f56a030169c02a95e1 100644 (file)
--- a/fs/bcachefs/recovery.c
+++ b/fs/bcachefs/recovery.c
@@ -278,7 +278,7 @@ out:
        return ret;
 err:
 fsck_err:
-       BUG_ON(!ret);
+       pr_err("Error in recovery: %s (%i)", err, ret);
        goto out;
 }
 
@@ -381,6 +381,6 @@ int bch2_fs_initialize(struct bch_fs *c)
 
        return 0;
 err:
-       BUG_ON(!ret);
+       pr_err("Error initializing new filesystem: %s (%i)", err, ret);
        return ret;
 }

diff --git a/fs/bcachefs/super-io.c b/fs/bcachefs/super-io.c
index 64c2375302a054c5683a884f17cf0e331a76fd87..58c35d9665eb349e3f5be1a30b665378f5c739c8 100644 (file)
--- a/fs/bcachefs/super-io.c
+++ b/fs/bcachefs/super-io.c
@@ -811,7 +811,7 @@ static const char *bch2_sb_validate_members(struct bch_sb *sb,
                        return "Too many buckets";
 
                if (le64_to_cpu(m->nbuckets) -
-                   le16_to_cpu(m->first_bucket) < 1 << 10)
+                   le16_to_cpu(m->first_bucket) < BCH_MIN_NR_NBUCKETS)
                        return "Not enough buckets";
 
                if (le16_to_cpu(m->bucket_size) <