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[PATCH] md: fix some locking and module refcounting issues with md's use of sysfs

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1/ I really should be using the __ATTR macros for defining attributes, so
   that the .owner field get set properly, otherwise modules can be removed
   while sysfs files are open.  This also involves some name changes of _show
   routines.

2/ Always lock the mddev (against reconfiguration) for all sysfs attribute
   access.  This easily avoid certain races and is completely consistant with
   other interfaces (ioctl and /proc/mdstat both always lock against
   reconfiguration).

3/ raid5 attributes must check that the 'conf' structure actually exists
   (the array could have been stopped while an attribute file was open).

4/ A missing 'kfree' from when the raid5_conf_t was converted to have a
   kobject embedded, and then converted back again.

Signed-off-by: Neil Brown <neilb@suse.de>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This commit is contained in:
NeilBrown
2005-11-08 21:39:39 -08:00
committed by Linus Torvalds
parent 3855ad9f39
commit 96de1e663c
2 changed files with 46 additions and 46 deletions
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62
drivers/md/md.c
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@ -1504,7 +1504,7 @@ struct rdev_sysfs_entry {
};
static ssize_t
rdev_show_state(mdk_rdev_t *rdev, char *page)
state_show(mdk_rdev_t *rdev, char *page)
{
char *sep = "";
int len=0;
@ -1525,13 +1525,11 @@ rdev_show_state(mdk_rdev_t *rdev, char *page)
return len+sprintf(page+len, "\n");
}
static struct rdev_sysfs_entry rdev_state = {
.attr = {.name = "state", .mode = S_IRUGO },
.show = rdev_show_state,
};
static struct rdev_sysfs_entry
rdev_state = __ATTR_RO(state);
static ssize_t
rdev_show_super(mdk_rdev_t *rdev, char *page)
super_show(mdk_rdev_t *rdev, char *page)
{
if (rdev->sb_loaded && rdev->sb_size) {
memcpy(page, page_address(rdev->sb_page), rdev->sb_size);
@ -1539,10 +1537,8 @@ rdev_show_super(mdk_rdev_t *rdev, char *page)
} else
return 0;
}
static struct rdev_sysfs_entry rdev_super = {
.attr = {.name = "super", .mode = S_IRUGO },
.show = rdev_show_super,
};
static struct rdev_sysfs_entry rdev_super = __ATTR_RO(super);
static struct attribute *rdev_default_attrs[] = {
&rdev_state.attr,
&rdev_super.attr,
@ -1728,7 +1724,7 @@ static void analyze_sbs(mddev_t * mddev)
}
static ssize_t
md_show_level(mddev_t *mddev, char *page)
level_show(mddev_t *mddev, char *page)
{
mdk_personality_t *p = mddev->pers;
if (p == NULL)
@ -1739,21 +1735,15 @@ md_show_level(mddev_t *mddev, char *page)
return sprintf(page, "%s\n", p->name);
}
static struct md_sysfs_entry md_level = {
.attr = {.name = "level", .mode = S_IRUGO },
.show = md_show_level,
};
static struct md_sysfs_entry md_level = __ATTR_RO(level);
static ssize_t
md_show_rdisks(mddev_t *mddev, char *page)
raid_disks_show(mddev_t *mddev, char *page)
{
return sprintf(page, "%d\n", mddev->raid_disks);
}
static struct md_sysfs_entry md_raid_disks = {
.attr = {.name = "raid_disks", .mode = S_IRUGO },
.show = md_show_rdisks,
};
static struct md_sysfs_entry md_raid_disks = __ATTR_RO(raid_disks);
static ssize_t
md_show_scan(mddev_t *mddev, char *page)
@ -1782,10 +1772,10 @@ md_store_scan(mddev_t *mddev, const char *page, size_t len)
if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery) ||
test_bit(MD_RECOVERY_NEEDED, &mddev->recovery))
return -EBUSY;
down(&mddev->reconfig_sem);
if (mddev->pers && mddev->pers->sync_request)
canscan=1;
up(&mddev->reconfig_sem);
if (!canscan)
return -EINVAL;
@ -1801,22 +1791,18 @@ md_store_scan(mddev_t *mddev, const char *page, size_t len)
}
static ssize_t
md_show_mismatch(mddev_t *mddev, char *page)
mismatch_cnt_show(mddev_t *mddev, char *page)
{
return sprintf(page, "%llu\n",
(unsigned long long) mddev->resync_mismatches);
}
static struct md_sysfs_entry md_scan_mode = {
.attr = {.name = "scan_mode", .mode = S_IRUGO|S_IWUSR },
.show = md_show_scan,
.store = md_store_scan,
};
static struct md_sysfs_entry
md_scan_mode = __ATTR(scan_mode, S_IRUGO|S_IWUSR, md_show_scan, md_store_scan);
static struct md_sysfs_entry md_mismatches = {
.attr = {.name = "mismatch_cnt", .mode = S_IRUGO },
.show = md_show_mismatch,
};
static struct md_sysfs_entry
md_mismatches = __ATTR_RO(mismatch_cnt);
static struct attribute *md_default_attrs[] = {
&md_level.attr,
@ -1831,10 +1817,14 @@ md_attr_show(struct kobject *kobj, struct attribute *attr, char *page)
{
struct md_sysfs_entry *entry = container_of(attr, struct md_sysfs_entry, attr);
mddev_t *mddev = container_of(kobj, struct mddev_s, kobj);
ssize_t rv;
if (!entry->show)
return -EIO;
return entry->show(mddev, page);
mddev_lock(mddev);
rv = entry->show(mddev, page);
mddev_unlock(mddev);
return rv;
}
static ssize_t
@ -1843,10 +1833,14 @@ md_attr_store(struct kobject *kobj, struct attribute *attr,
{
struct md_sysfs_entry *entry = container_of(attr, struct md_sysfs_entry, attr);
mddev_t *mddev = container_of(kobj, struct mddev_s, kobj);
ssize_t rv;
if (!entry->store)
return -EIO;
return entry->store(mddev, page, length);
mddev_lock(mddev);
rv = entry->store(mddev, page, length);
mddev_unlock(mddev);
return rv;
}
static void md_free(struct kobject *ko)