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-rw-r--r--fs/ubifs/tnc_commit.c145
1 files changed, 63 insertions, 82 deletions
diff --git a/fs/ubifs/tnc_commit.c b/fs/ubifs/tnc_commit.c
index 41920f3..4c15f07 100644
--- a/fs/ubifs/tnc_commit.c
+++ b/fs/ubifs/tnc_commit.c
@@ -22,6 +22,7 @@
/* This file implements TNC functions for committing */
+#include <linux/random.h>
#include "ubifs.h"
/**
@@ -87,8 +88,12 @@ static int make_idx_node(struct ubifs_info *c, struct ubifs_idx_node *idx,
atomic_long_dec(&c->dirty_zn_cnt);
ubifs_assert(ubifs_zn_dirty(znode));
- ubifs_assert(test_bit(COW_ZNODE, &znode->flags));
+ ubifs_assert(ubifs_zn_cow(znode));
+ /*
+ * Note, unlike 'write_index()' we do not add memory barriers here
+ * because this function is called with @c->tnc_mutex locked.
+ */
__clear_bit(DIRTY_ZNODE, &znode->flags);
__clear_bit(COW_ZNODE, &znode->flags);
@@ -377,7 +382,7 @@ static int layout_in_gaps(struct ubifs_info *c, int cnt)
c->gap_lebs = NULL;
return err;
}
- if (dbg_force_in_the_gaps_enabled()) {
+ if (!dbg_is_chk_index(c)) {
/*
* Do not print scary warnings if the debugging
* option which forces in-the-gaps is enabled.
@@ -491,25 +496,6 @@ static int layout_in_empty_space(struct ubifs_info *c)
else
next_len = ubifs_idx_node_sz(c, cnext->child_cnt);
- if (c->min_io_size == 1) {
- buf_offs += ALIGN(len, 8);
- if (next_len) {
- if (buf_offs + next_len <= c->leb_size)
- continue;
- err = ubifs_update_one_lp(c, lnum, 0,
- c->leb_size - buf_offs, 0, 0);
- if (err)
- return err;
- lnum = -1;
- continue;
- }
- err = ubifs_update_one_lp(c, lnum,
- c->leb_size - buf_offs, 0, 0, 0);
- if (err)
- return err;
- break;
- }
-
/* Update buffer positions */
wlen = used + len;
used += ALIGN(len, 8);
@@ -658,7 +644,7 @@ static int get_znodes_to_commit(struct ubifs_info *c)
}
cnt += 1;
while (1) {
- ubifs_assert(!test_bit(COW_ZNODE, &znode->flags));
+ ubifs_assert(!ubifs_zn_cow(znode));
__set_bit(COW_ZNODE, &znode->flags);
znode->alt = 0;
cnext = find_next_dirty(znode);
@@ -704,7 +690,7 @@ static int alloc_idx_lebs(struct ubifs_info *c, int cnt)
c->ilebs[c->ileb_cnt++] = lnum;
dbg_cmt("LEB %d", lnum);
}
- if (dbg_force_in_the_gaps())
+ if (dbg_is_chk_index(c) && !(random32() & 7))
return -ENOSPC;
return 0;
}
@@ -830,7 +816,7 @@ static int write_index(struct ubifs_info *c)
struct ubifs_idx_node *idx;
struct ubifs_znode *znode, *cnext;
int i, lnum, offs, len, next_len, buf_len, buf_offs, used;
- int avail, wlen, err, lnum_pos = 0;
+ int avail, wlen, err, lnum_pos = 0, blen, nxt_offs;
cnext = c->enext;
if (!cnext)
@@ -907,7 +893,7 @@ static int write_index(struct ubifs_info *c)
cnext = znode->cnext;
ubifs_assert(ubifs_zn_dirty(znode));
- ubifs_assert(test_bit(COW_ZNODE, &znode->flags));
+ ubifs_assert(ubifs_zn_cow(znode));
/*
* It is important that other threads should see %DIRTY_ZNODE
@@ -922,6 +908,28 @@ static int write_index(struct ubifs_info *c)
clear_bit(COW_ZNODE, &znode->flags);
smp_mb__after_clear_bit();
+ /*
+ * We have marked the znode as clean but have not updated the
+ * @c->clean_zn_cnt counter. If this znode becomes dirty again
+ * before 'free_obsolete_znodes()' is called, then
+ * @c->clean_zn_cnt will be decremented before it gets
+ * incremented (resulting in 2 decrements for the same znode).
+ * This means that @c->clean_zn_cnt may become negative for a
+ * while.
+ *
+ * Q: why we cannot increment @c->clean_zn_cnt?
+ * A: because we do not have the @c->tnc_mutex locked, and the
+ * following code would be racy and buggy:
+ *
+ * if (!ubifs_zn_obsolete(znode)) {
+ * atomic_long_inc(&c->clean_zn_cnt);
+ * atomic_long_inc(&ubifs_clean_zn_cnt);
+ * }
+ *
+ * Thus, we just delay the @c->clean_zn_cnt update until we
+ * have the mutex locked.
+ */
+
/* Do not access znode from this point on */
/* Update buffer positions */
@@ -938,65 +946,38 @@ static int write_index(struct ubifs_info *c)
else
next_len = ubifs_idx_node_sz(c, cnext->child_cnt);
- if (c->min_io_size == 1) {
- /*
- * Write the prepared index node immediately if there is
- * no minimum IO size
- */
- err = ubifs_leb_write(c, lnum, c->cbuf, buf_offs,
- wlen, UBI_SHORTTERM);
- if (err)
- return err;
- buf_offs += ALIGN(wlen, 8);
- if (next_len) {
- used = 0;
- avail = buf_len;
- if (buf_offs + next_len > c->leb_size) {
- err = ubifs_update_one_lp(c, lnum,
- LPROPS_NC, 0, 0, LPROPS_TAKEN);
- if (err)
- return err;
- lnum = -1;
- }
+ nxt_offs = buf_offs + used + next_len;
+ if (next_len && nxt_offs <= c->leb_size) {
+ if (avail > 0)
continue;
- }
+ else
+ blen = buf_len;
} else {
- int blen, nxt_offs = buf_offs + used + next_len;
-
- if (next_len && nxt_offs <= c->leb_size) {
- if (avail > 0)
- continue;
- else
- blen = buf_len;
- } else {
- wlen = ALIGN(wlen, 8);
- blen = ALIGN(wlen, c->min_io_size);
- ubifs_pad(c, c->cbuf + wlen, blen - wlen);
- }
- /*
- * The buffer is full or there are no more znodes
- * to do
- */
- err = ubifs_leb_write(c, lnum, c->cbuf, buf_offs,
- blen, UBI_SHORTTERM);
- if (err)
- return err;
- buf_offs += blen;
- if (next_len) {
- if (nxt_offs > c->leb_size) {
- err = ubifs_update_one_lp(c, lnum,
- LPROPS_NC, 0, 0, LPROPS_TAKEN);
- if (err)
- return err;
- lnum = -1;
- }
- used -= blen;
- if (used < 0)
- used = 0;
- avail = buf_len - used;
- memmove(c->cbuf, c->cbuf + blen, used);
- continue;
+ wlen = ALIGN(wlen, 8);
+ blen = ALIGN(wlen, c->min_io_size);
+ ubifs_pad(c, c->cbuf + wlen, blen - wlen);
+ }
+
+ /* The buffer is full or there are no more znodes to do */
+ err = ubifs_leb_write(c, lnum, c->cbuf, buf_offs, blen,
+ UBI_SHORTTERM);
+ if (err)
+ return err;
+ buf_offs += blen;
+ if (next_len) {
+ if (nxt_offs > c->leb_size) {
+ err = ubifs_update_one_lp(c, lnum, LPROPS_NC, 0,
+ 0, LPROPS_TAKEN);
+ if (err)
+ return err;
+ lnum = -1;
}
+ used -= blen;
+ if (used < 0)
+ used = 0;
+ avail = buf_len - used;
+ memmove(c->cbuf, c->cbuf + blen, used);
+ continue;
}
break;
}
@@ -1029,7 +1010,7 @@ static void free_obsolete_znodes(struct ubifs_info *c)
do {
znode = cnext;
cnext = znode->cnext;
- if (test_bit(OBSOLETE_ZNODE, &znode->flags))
+ if (ubifs_zn_obsolete(znode))
kfree(znode);
else {
znode->cnext = NULL;
generated by cgit v1.1 at 2024-04-19 10:41:28 +0000