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| author | Josef Bacik <jwhiter@redhat.com> | 2007-05-16 15:56:13 -0400 |
|---|---|---|
| committer | Steven Whitehouse <swhiteho@redhat.com> | 2007-07-09 08:22:29 +0100 |
| commit | 916297aad5de2363dccd531873eda55d4d6afb57 (patch) | |
| tree | e8e5eabf529bd4a41d9ee225087e237581ce5ffd /fs/dlm/debug_fs.c | |
| parent | 2a87ab080607d009b8b2a8706f4e27d70402ca9c (diff) | |
| download | linux-3.10-916297aad5de2363dccd531873eda55d4d6afb57.tar.gz linux-3.10-916297aad5de2363dccd531873eda55d4d6afb57.tar.bz2 linux-3.10-916297aad5de2363dccd531873eda55d4d6afb57.zip | |
[DLM] keep dlm from panicing when traversing rsb list in debugfs
This problem was originally reported against GFS6.1, but the same issue exists
in upstream DLM. This patch keeps the rsb iterator assigning under the rsbtbl
list lock. Each time we process an rsb we grab a reference to it to make sure
it is not freed out from underneath us, and then put it when we get the next rsb
in the list or move onto another list.
Signed-off-by: Josef Bacik <jwhiter@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
Diffstat (limited to 'fs/dlm/debug_fs.c')
| -rw-r--r-- | fs/dlm/debug_fs.c | 9 |
1 files changed, 8 insertions, 1 deletions
diff --git a/fs/dlm/debug_fs.c b/fs/dlm/debug_fs.c index 61ba670b9e0..9e27a167579 100644 --- a/fs/dlm/debug_fs.c +++ b/fs/dlm/debug_fs.c @@ -17,6 +17,7 @@ #include <linux/debugfs.h> #include "dlm_internal.h" +#include "lock.h" #define DLM_DEBUG_BUF_LEN 4096 static char debug_buf[DLM_DEBUG_BUF_LEN]; @@ -166,6 +167,9 @@ static int rsb_iter_next(struct rsb_iter *ri) read_lock(&ls->ls_rsbtbl[i].lock); if (!list_empty(&ls->ls_rsbtbl[i].list)) { ri->next = ls->ls_rsbtbl[i].list.next; + ri->rsb = list_entry(ri->next, struct dlm_rsb, + res_hashchain); + dlm_hold_rsb(ri->rsb); read_unlock(&ls->ls_rsbtbl[i].lock); break; } @@ -176,6 +180,7 @@ static int rsb_iter_next(struct rsb_iter *ri) if (ri->entry >= ls->ls_rsbtbl_size) return 1; } else { + struct dlm_rsb *old = ri->rsb; i = ri->entry; read_lock(&ls->ls_rsbtbl[i].lock); ri->next = ri->next->next; @@ -184,11 +189,13 @@ static int rsb_iter_next(struct rsb_iter *ri) ri->next = NULL; ri->entry++; read_unlock(&ls->ls_rsbtbl[i].lock); + dlm_put_rsb(old); goto top; } + ri->rsb = list_entry(ri->next, struct dlm_rsb, res_hashchain); read_unlock(&ls->ls_rsbtbl[i].lock); + dlm_put_rsb(old); } - ri->rsb = list_entry(ri->next, struct dlm_rsb, res_hashchain); return 0; } |