diff options
| author | NeilBrown <neilb@suse.de> | 2010-01-29 06:20:08 +0100 |
|---|---|---|
| committer | NeilBrown <neilb@suse.de> | 2010-01-29 06:20:08 +0100 |
| commit | fc7e81e54ec37ece4f1a8ec1729933fc22ec25ff (patch) | |
| tree | 43c375e4db15bf5f18c49afbcafc473792c89cdb /mapfile.c | |
| parent | Detail: Report state of FAILED when an array has too few devices to work. (diff) | |
| download | mdadm-fc7e81e54ec37ece4f1a8ec1729933fc22ec25ff.tar.xz mdadm-fc7e81e54ec37ece4f1a8ec1729933fc22ec25ff.zip | |
mapfile: fix locking.
The current locking uses lockf, and is completely broken.
When you hold a lockf lock, any close of any fd on that file will
release the lock. So map_read() call which is made as soon as we get
the lock, will immediately drop the lock.
So change to flock locking which isn't so badly designed.
Signed-off-by: NeilBrown <neilb@suse.de>
Diffstat (limited to 'mapfile.c')
| -rw-r--r-- | mapfile.c | 7 |
1 files changed, 5 insertions, 2 deletions
@@ -48,6 +48,7 @@ * one that we can. */ #include "mdadm.h" +#include <sys/file.h> #include <ctype.h> #define mapnames(base) { #base, #base ".new", #base ".lock"} @@ -115,7 +116,7 @@ int map_lock(struct map_ent **melp) lf = open_map(2, &lwhich); if (lf == NULL) return -1; - if (lockf(fileno(lf), F_LOCK, 0) != 0) { + if (flock(fileno(lf), LOCK_EX) != 0) { fclose(lf); lf = NULL; return -1; @@ -129,8 +130,10 @@ int map_lock(struct map_ent **melp) void map_unlock(struct map_ent **melp) { - if (lf) + if (lf) { + flock(fileno(lf), LOCK_UN); fclose(lf); + } unlink(mapname[lwhich][2]); lf = NULL; } |