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| author | Joern Engel <joern@logfs.org> | 2010-04-13 17:46:37 +0200 |
|---|---|---|
| committer | Joern Engel <joern@logfs.org> | 2010-04-13 17:46:37 +0200 |
| commit | 032d8f7268444a0f5d4ee02d9513d682d5b8edfc (patch) | |
| tree | 57cd841514abb9ffe7df7d2569513663f551f960 /fs/logfs/logfs.h | |
| parent | e05c378f4973674a16d5b9636f2310cf88aca5f2 (diff) | |
| download | linux-032d8f7268444a0f5d4ee02d9513d682d5b8edfc.tar.gz linux-032d8f7268444a0f5d4ee02d9513d682d5b8edfc.tar.bz2 linux-032d8f7268444a0f5d4ee02d9513d682d5b8edfc.zip | |
[LogFS] Prevent memory corruption on large deletes
Removing sufficiently large files would create aliases for a large
number of segments. This in turn results in a large number of journal
entries and an overflow of s_je_array.
Cheap fix is to add a BUG_ON, turning memory corruption into something
annoying, but less dangerous. Real fix is to count the number of
affected segments and prevent the problem completely.
Signed-off-by: Joern Engel <joern@logfs.org>
Diffstat (limited to 'fs/logfs/logfs.h')
| -rw-r--r-- | fs/logfs/logfs.h | 8 |
1 files changed, 7 insertions, 1 deletions
diff --git a/fs/logfs/logfs.h b/fs/logfs/logfs.h index 97195b9e93a5..c9929eed80b1 100644 --- a/fs/logfs/logfs.h +++ b/fs/logfs/logfs.h @@ -257,10 +257,14 @@ struct logfs_shadow { * struct shadow_tree * @new: shadows where old_ofs==0, indexed by new_ofs * @old: shadows where old_ofs!=0, indexed by old_ofs + * @segment_map: bitfield of segments containing shadows + * @no_shadowed_segment: number of segments containing shadows */ struct shadow_tree { struct btree_head64 new; struct btree_head64 old; + struct btree_head32 segment_map; + int no_shadowed_segments; }; struct object_alias_item { @@ -311,6 +315,8 @@ struct logfs_block_ops { write_alias_t *write_one_alias); }; +#define MAX_JOURNAL_ENTRIES 256 + struct logfs_super { struct mtd_info *s_mtd; /* underlying device */ struct block_device *s_bdev; /* underlying device */ @@ -377,7 +383,7 @@ struct logfs_super { u32 s_journal_ec[LOGFS_JOURNAL_SEGS]; /* journal erasecounts */ u64 s_last_version; struct logfs_area *s_journal_area; /* open journal segment */ - __be64 s_je_array[64]; + __be64 s_je_array[MAX_JOURNAL_ENTRIES]; int s_no_je; int s_sum_index; /* for the 12 summaries */ |