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Diffstat (limited to 'fs/ocfs2/dlmglue.c')
-rw-r--r--fs/ocfs2/dlmglue.c546
1 files changed, 403 insertions, 143 deletions
diff --git a/fs/ocfs2/dlmglue.c b/fs/ocfs2/dlmglue.c
index 4e97dcceaf8..3867244fb14 100644
--- a/fs/ocfs2/dlmglue.c
+++ b/fs/ocfs2/dlmglue.c
@@ -55,7 +55,6 @@
#include "slot_map.h"
#include "super.h"
#include "uptodate.h"
-#include "vote.h"
#include "buffer_head_io.h"
@@ -69,6 +68,7 @@ struct ocfs2_mask_waiter {
static struct ocfs2_super *ocfs2_get_dentry_osb(struct ocfs2_lock_res *lockres);
static struct ocfs2_super *ocfs2_get_inode_osb(struct ocfs2_lock_res *lockres);
+static struct ocfs2_super *ocfs2_get_file_osb(struct ocfs2_lock_res *lockres);
/*
* Return value from ->downconvert_worker functions.
@@ -153,10 +153,10 @@ struct ocfs2_lock_res_ops {
struct ocfs2_super * (*get_osb)(struct ocfs2_lock_res *);
/*
- * Optionally called in the downconvert (or "vote") thread
- * after a successful downconvert. The lockres will not be
- * referenced after this callback is called, so it is safe to
- * free memory, etc.
+ * Optionally called in the downconvert thread after a
+ * successful downconvert. The lockres will not be referenced
+ * after this callback is called, so it is safe to free
+ * memory, etc.
*
* The exact semantics of when this is called are controlled
* by ->downconvert_worker()
@@ -225,17 +225,12 @@ static struct ocfs2_lock_res_ops ocfs2_inode_rw_lops = {
.flags = 0,
};
-static struct ocfs2_lock_res_ops ocfs2_inode_meta_lops = {
+static struct ocfs2_lock_res_ops ocfs2_inode_inode_lops = {
.get_osb = ocfs2_get_inode_osb,
.check_downconvert = ocfs2_check_meta_downconvert,
.set_lvb = ocfs2_set_meta_lvb,
- .flags = LOCK_TYPE_REQUIRES_REFRESH|LOCK_TYPE_USES_LVB,
-};
-
-static struct ocfs2_lock_res_ops ocfs2_inode_data_lops = {
- .get_osb = ocfs2_get_inode_osb,
.downconvert_worker = ocfs2_data_convert_worker,
- .flags = 0,
+ .flags = LOCK_TYPE_REQUIRES_REFRESH|LOCK_TYPE_USES_LVB,
};
static struct ocfs2_lock_res_ops ocfs2_super_lops = {
@@ -258,10 +253,14 @@ static struct ocfs2_lock_res_ops ocfs2_inode_open_lops = {
.flags = 0,
};
+static struct ocfs2_lock_res_ops ocfs2_flock_lops = {
+ .get_osb = ocfs2_get_file_osb,
+ .flags = 0,
+};
+
static inline int ocfs2_is_inode_lock(struct ocfs2_lock_res *lockres)
{
return lockres->l_type == OCFS2_LOCK_TYPE_META ||
- lockres->l_type == OCFS2_LOCK_TYPE_DATA ||
lockres->l_type == OCFS2_LOCK_TYPE_RW ||
lockres->l_type == OCFS2_LOCK_TYPE_OPEN;
}
@@ -310,12 +309,24 @@ static inline void ocfs2_recover_from_dlm_error(struct ocfs2_lock_res *lockres,
"resource %s: %s\n", dlm_errname(_stat), _func, \
_lockres->l_name, dlm_errmsg(_stat)); \
} while (0)
-static void ocfs2_vote_on_unlock(struct ocfs2_super *osb,
- struct ocfs2_lock_res *lockres);
-static int ocfs2_meta_lock_update(struct inode *inode,
+static int ocfs2_downconvert_thread(void *arg);
+static void ocfs2_downconvert_on_unlock(struct ocfs2_super *osb,
+ struct ocfs2_lock_res *lockres);
+static int ocfs2_inode_lock_update(struct inode *inode,
struct buffer_head **bh);
static void ocfs2_drop_osb_locks(struct ocfs2_super *osb);
static inline int ocfs2_highest_compat_lock_level(int level);
+static void ocfs2_prepare_downconvert(struct ocfs2_lock_res *lockres,
+ int new_level);
+static int ocfs2_downconvert_lock(struct ocfs2_super *osb,
+ struct ocfs2_lock_res *lockres,
+ int new_level,
+ int lvb);
+static int ocfs2_prepare_cancel_convert(struct ocfs2_super *osb,
+ struct ocfs2_lock_res *lockres);
+static int ocfs2_cancel_convert(struct ocfs2_super *osb,
+ struct ocfs2_lock_res *lockres);
+
static void ocfs2_build_lock_name(enum ocfs2_lock_type type,
u64 blkno,
@@ -402,10 +413,7 @@ void ocfs2_inode_lock_res_init(struct ocfs2_lock_res *res,
ops = &ocfs2_inode_rw_lops;
break;
case OCFS2_LOCK_TYPE_META:
- ops = &ocfs2_inode_meta_lops;
- break;
- case OCFS2_LOCK_TYPE_DATA:
- ops = &ocfs2_inode_data_lops;
+ ops = &ocfs2_inode_inode_lops;
break;
case OCFS2_LOCK_TYPE_OPEN:
ops = &ocfs2_inode_open_lops;
@@ -428,6 +436,13 @@ static struct ocfs2_super *ocfs2_get_inode_osb(struct ocfs2_lock_res *lockres)
return OCFS2_SB(inode->i_sb);
}
+static struct ocfs2_super *ocfs2_get_file_osb(struct ocfs2_lock_res *lockres)
+{
+ struct ocfs2_file_private *fp = lockres->l_priv;
+
+ return OCFS2_SB(fp->fp_file->f_mapping->host->i_sb);
+}
+
static __u64 ocfs2_get_dentry_lock_ino(struct ocfs2_lock_res *lockres)
{
__be64 inode_blkno_be;
@@ -508,6 +523,21 @@ static void ocfs2_rename_lock_res_init(struct ocfs2_lock_res *res,
&ocfs2_rename_lops, osb);
}
+void ocfs2_file_lock_res_init(struct ocfs2_lock_res *lockres,
+ struct ocfs2_file_private *fp)
+{
+ struct inode *inode = fp->fp_file->f_mapping->host;
+ struct ocfs2_inode_info *oi = OCFS2_I(inode);
+
+ ocfs2_lock_res_init_once(lockres);
+ ocfs2_build_lock_name(OCFS2_LOCK_TYPE_FLOCK, oi->ip_blkno,
+ inode->i_generation, lockres->l_name);
+ ocfs2_lock_res_init_common(OCFS2_SB(inode->i_sb), lockres,
+ OCFS2_LOCK_TYPE_FLOCK, &ocfs2_flock_lops,
+ fp);
+ lockres->l_flags |= OCFS2_LOCK_NOCACHE;
+}
+
void ocfs2_lock_res_free(struct ocfs2_lock_res *res)
{
mlog_entry_void();
@@ -724,6 +754,13 @@ static void ocfs2_blocking_ast(void *opaque, int level)
lockres->l_name, level, lockres->l_level,
ocfs2_lock_type_string(lockres->l_type));
+ /*
+ * We can skip the bast for locks which don't enable caching -
+ * they'll be dropped at the earliest possible time anyway.
+ */
+ if (lockres->l_flags & OCFS2_LOCK_NOCACHE)
+ return;
+
spin_lock_irqsave(&lockres->l_lock, flags);
needs_downconvert = ocfs2_generic_handle_bast(lockres, level);
if (needs_downconvert)
@@ -732,7 +769,7 @@ static void ocfs2_blocking_ast(void *opaque, int level)
wake_up(&lockres->l_event);
- ocfs2_kick_vote_thread(osb);
+ ocfs2_wake_downconvert_thread(osb);
}
static void ocfs2_locking_ast(void *opaque)
@@ -935,6 +972,21 @@ static int lockres_remove_mask_waiter(struct ocfs2_lock_res *lockres,
}
+static int ocfs2_wait_for_mask_interruptible(struct ocfs2_mask_waiter *mw,
+ struct ocfs2_lock_res *lockres)
+{
+ int ret;
+
+ ret = wait_for_completion_interruptible(&mw->mw_complete);
+ if (ret)
+ lockres_remove_mask_waiter(lockres, mw);
+ else
+ ret = mw->mw_status;
+ /* Re-arm the completion in case we want to wait on it again */
+ INIT_COMPLETION(mw->mw_complete);
+ return ret;
+}
+
static int ocfs2_cluster_lock(struct ocfs2_super *osb,
struct ocfs2_lock_res *lockres,
int level,
@@ -1089,7 +1141,7 @@ static void ocfs2_cluster_unlock(struct ocfs2_super *osb,
mlog_entry_void();
spin_lock_irqsave(&lockres->l_lock, flags);
ocfs2_dec_holders(lockres, level);
- ocfs2_vote_on_unlock(osb, lockres);
+ ocfs2_downconvert_on_unlock(osb, lockres);
spin_unlock_irqrestore(&lockres->l_lock, flags);
mlog_exit_void();
}
@@ -1147,13 +1199,7 @@ int ocfs2_create_new_inode_locks(struct inode *inode)
* We don't want to use LKM_LOCAL on a meta data lock as they
* don't use a generation in their lock names.
*/
- ret = ocfs2_create_new_lock(osb, &OCFS2_I(inode)->ip_meta_lockres, 1, 0);
- if (ret) {
- mlog_errno(ret);
- goto bail;
- }
-
- ret = ocfs2_create_new_lock(osb, &OCFS2_I(inode)->ip_data_lockres, 1, 1);
+ ret = ocfs2_create_new_lock(osb, &OCFS2_I(inode)->ip_inode_lockres, 1, 0);
if (ret) {
mlog_errno(ret);
goto bail;
@@ -1311,76 +1357,221 @@ out:
mlog_exit_void();
}
-int ocfs2_data_lock_full(struct inode *inode,
- int write,
- int arg_flags)
+static int ocfs2_flock_handle_signal(struct ocfs2_lock_res *lockres,
+ int level)
{
- int status = 0, level;
- struct ocfs2_lock_res *lockres;
- struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
+ int ret;
+ struct ocfs2_super *osb = ocfs2_get_lockres_osb(lockres);
+ unsigned long flags;
+ struct ocfs2_mask_waiter mw;
- BUG_ON(!inode);
+ ocfs2_init_mask_waiter(&mw);
- mlog_entry_void();
+retry_cancel:
+ spin_lock_irqsave(&lockres->l_lock, flags);
+ if (lockres->l_flags & OCFS2_LOCK_BUSY) {
+ ret = ocfs2_prepare_cancel_convert(osb, lockres);
+ if (ret) {
+ spin_unlock_irqrestore(&lockres->l_lock, flags);
+ ret = ocfs2_cancel_convert(osb, lockres);
+ if (ret < 0) {
+ mlog_errno(ret);
+ goto out;
+ }
+ goto retry_cancel;
+ }
+ lockres_add_mask_waiter(lockres, &mw, OCFS2_LOCK_BUSY, 0);
+ spin_unlock_irqrestore(&lockres->l_lock, flags);
- mlog(0, "inode %llu take %s DATA lock\n",
- (unsigned long long)OCFS2_I(inode)->ip_blkno,
- write ? "EXMODE" : "PRMODE");
+ ocfs2_wait_for_mask(&mw);
+ goto retry_cancel;
+ }
- /* We'll allow faking a readonly data lock for
- * rodevices. */
- if (ocfs2_is_hard_readonly(OCFS2_SB(inode->i_sb))) {
- if (write) {
- status = -EROFS;
- mlog_errno(status);
+ ret = -ERESTARTSYS;
+ /*
+ * We may still have gotten the lock, in which case there's no
+ * point to restarting the syscall.
+ */
+ if (lockres->l_level == level)
+ ret = 0;
+
+ mlog(0, "Cancel returning %d. flags: 0x%lx, level: %d, act: %d\n", ret,
+ lockres->l_flags, lockres->l_level, lockres->l_action);
+
+ spin_unlock_irqrestore(&lockres->l_lock, flags);
+
+out:
+ return ret;
+}
+
+/*
+ * ocfs2_file_lock() and ocfs2_file_unlock() map to a single pair of
+ * flock() calls. The locking approach this requires is sufficiently
+ * different from all other cluster lock types that we implement a
+ * seperate path to the "low-level" dlm calls. In particular:
+ *
+ * - No optimization of lock levels is done - we take at exactly
+ * what's been requested.
+ *
+ * - No lock caching is employed. We immediately downconvert to
+ * no-lock at unlock time. This also means flock locks never go on
+ * the blocking list).
+ *
+ * - Since userspace can trivially deadlock itself with flock, we make
+ * sure to allow cancellation of a misbehaving applications flock()
+ * request.
+ *
+ * - Access to any flock lockres doesn't require concurrency, so we
+ * can simplify the code by requiring the caller to guarantee
+ * serialization of dlmglue flock calls.
+ */
+int ocfs2_file_lock(struct file *file, int ex, int trylock)
+{
+ int ret, level = ex ? LKM_EXMODE : LKM_PRMODE;
+ unsigned int lkm_flags = trylock ? LKM_NOQUEUE : 0;
+ unsigned long flags;
+ struct ocfs2_file_private *fp = file->private_data;
+ struct ocfs2_lock_res *lockres = &fp->fp_flock;
+ struct ocfs2_super *osb = OCFS2_SB(file->f_mapping->host->i_sb);
+ struct ocfs2_mask_waiter mw;
+
+ ocfs2_init_mask_waiter(&mw);
+
+ if ((lockres->l_flags & OCFS2_LOCK_BUSY) ||
+ (lockres->l_level > LKM_NLMODE)) {
+ mlog(ML_ERROR,
+ "File lock \"%s\" has busy or locked state: flags: 0x%lx, "
+ "level: %u\n", lockres->l_name, lockres->l_flags,
+ lockres->l_level);
+ return -EINVAL;
+ }
+
+ spin_lock_irqsave(&lockres->l_lock, flags);
+ if (!(lockres->l_flags & OCFS2_LOCK_ATTACHED)) {
+ lockres_add_mask_waiter(lockres, &mw, OCFS2_LOCK_BUSY, 0);
+ spin_unlock_irqrestore(&lockres->l_lock, flags);
+
+ /*
+ * Get the lock at NLMODE to start - that way we
+ * can cancel the upconvert request if need be.
+ */
+ ret = ocfs2_lock_create(osb, lockres, LKM_NLMODE, 0);
+ if (ret < 0) {
+ mlog_errno(ret);
+ goto out;
}
- goto out;
+
+ ret = ocfs2_wait_for_mask(&mw);
+ if (ret) {
+ mlog_errno(ret);
+ goto out;
+ }
+ spin_lock_irqsave(&lockres->l_lock, flags);
}
- if (ocfs2_mount_local(osb))
- goto out;
+ lockres->l_action = OCFS2_AST_CONVERT;
+ lkm_flags |= LKM_CONVERT;
+ lockres->l_requested = level;
+ lockres_or_flags(lockres, OCFS2_LOCK_BUSY);
- lockres = &OCFS2_I(inode)->ip_data_lockres;
+ lockres_add_mask_waiter(lockres, &mw, OCFS2_LOCK_BUSY, 0);
+ spin_unlock_irqrestore(&lockres->l_lock, flags);
- level = write ? LKM_EXMODE : LKM_PRMODE;
+ ret = dlmlock(osb->dlm, level, &lockres->l_lksb, lkm_flags,
+ lockres->l_name, OCFS2_LOCK_ID_MAX_LEN - 1,
+ ocfs2_locking_ast, lockres, ocfs2_blocking_ast);
+ if (ret != DLM_NORMAL) {
+ if (trylock && ret == DLM_NOTQUEUED)
+ ret = -EAGAIN;
+ else {
+ ocfs2_log_dlm_error("dlmlock", ret, lockres);
+ ret = -EINVAL;
+ }
- status = ocfs2_cluster_lock(OCFS2_SB(inode->i_sb), lockres, level,
- 0, arg_flags);
- if (status < 0 && status != -EAGAIN)
- mlog_errno(status);
+ ocfs2_recover_from_dlm_error(lockres, 1);
+ lockres_remove_mask_waiter(lockres, &mw);
+ goto out;
+ }
+
+ ret = ocfs2_wait_for_mask_interruptible(&mw, lockres);
+ if (ret == -ERESTARTSYS) {
+ /*
+ * Userspace can cause deadlock itself with
+ * flock(). Current behavior locally is to allow the
+ * deadlock, but abort the system call if a signal is
+ * received. We follow this example, otherwise a
+ * poorly written program could sit in kernel until
+ * reboot.
+ *
+ * Handling this is a bit more complicated for Ocfs2
+ * though. We can't exit this function with an
+ * outstanding lock request, so a cancel convert is
+ * required. We intentionally overwrite 'ret' - if the
+ * cancel fails and the lock was granted, it's easier
+ * to just bubble sucess back up to the user.
+ */
+ ret = ocfs2_flock_handle_signal(lockres, level);
+ }
out:
- mlog_exit(status);
- return status;
+
+ mlog(0, "Lock: \"%s\" ex: %d, trylock: %d, returns: %d\n",
+ lockres->l_name, ex, trylock, ret);
+ return ret;
}
-/* see ocfs2_meta_lock_with_page() */
-int ocfs2_data_lock_with_page(struct inode *inode,
- int write,
- struct page *page)
+void ocfs2_file_unlock(struct file *file)
{
int ret;
+ unsigned long flags;
+ struct ocfs2_file_private *fp = file->private_data;
+ struct ocfs2_lock_res *lockres = &fp->fp_flock;
+ struct ocfs2_super *osb = OCFS2_SB(file->f_mapping->host->i_sb);
+ struct ocfs2_mask_waiter mw;
- ret = ocfs2_data_lock_full(inode, write, OCFS2_LOCK_NONBLOCK);
- if (ret == -EAGAIN) {
- unlock_page(page);
- if (ocfs2_data_lock(inode, write) == 0)
- ocfs2_data_unlock(inode, write);
- ret = AOP_TRUNCATED_PAGE;
+ ocfs2_init_mask_waiter(&mw);
+
+ if (!(lockres->l_flags & OCFS2_LOCK_ATTACHED))
+ return;
+
+ if (lockres->l_level == LKM_NLMODE)
+ return;
+
+ mlog(0, "Unlock: \"%s\" flags: 0x%lx, level: %d, act: %d\n",
+ lockres->l_name, lockres->l_flags, lockres->l_level,
+ lockres->l_action);
+
+ spin_lock_irqsave(&lockres->l_lock, flags);
+ /*
+ * Fake a blocking ast for the downconvert code.
+ */
+ lockres_or_flags(lockres, OCFS2_LOCK_BLOCKED);
+ lockres->l_blocking = LKM_EXMODE;
+
+ ocfs2_prepare_downconvert(lockres, LKM_NLMODE);
+ lockres_add_mask_waiter(lockres, &mw, OCFS2_LOCK_BUSY, 0);
+ spin_unlock_irqrestore(&lockres->l_lock, flags);
+
+ ret = ocfs2_downconvert_lock(osb, lockres, LKM_NLMODE, 0);
+ if (ret) {
+ mlog_errno(ret);
+ return;
}
- return ret;
+ ret = ocfs2_wait_for_mask(&mw);
+ if (ret)
+ mlog_errno(ret);
}
-static void ocfs2_vote_on_unlock(struct ocfs2_super *osb,
- struct ocfs2_lock_res *lockres)
+static void ocfs2_downconvert_on_unlock(struct ocfs2_super *osb,
+ struct ocfs2_lock_res *lockres)
{
int kick = 0;
mlog_entry_void();
/* If we know that another node is waiting on our lock, kick
- * the vote thread * pre-emptively when we reach a release
+ * the downconvert thread * pre-emptively when we reach a release
* condition. */
if (lockres->l_flags & OCFS2_LOCK_BLOCKED) {
switch(lockres->l_blocking) {
@@ -1398,27 +1589,7 @@ static void ocfs2_vote_on_unlock(struct ocfs2_super *osb,
}
if (kick)
- ocfs2_kick_vote_thread(osb);
-
- mlog_exit_void();
-}
-
-void ocfs2_data_unlock(struct inode *inode,
- int write)
-{
- int level = write ? LKM_EXMODE : LKM_PRMODE;
- struct ocfs2_lock_res *lockres = &OCFS2_I(inode)->ip_data_lockres;
- struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
-
- mlog_entry_void();
-
- mlog(0, "inode %llu drop %s DATA lock\n",
- (unsigned long long)OCFS2_I(inode)->ip_blkno,
- write ? "EXMODE" : "PRMODE");
-
- if (!ocfs2_is_hard_readonly(OCFS2_SB(inode->i_sb)) &&
- !ocfs2_mount_local(osb))
- ocfs2_cluster_unlock(OCFS2_SB(inode->i_sb), lockres, level);
+ ocfs2_wake_downconvert_thread(osb);
mlog_exit_void();
}
@@ -1442,11 +1613,11 @@ static u64 ocfs2_pack_timespec(struct timespec *spec)
/* Call this with the lockres locked. I am reasonably sure we don't
* need ip_lock in this function as anyone who would be changing those
- * values is supposed to be blocked in ocfs2_meta_lock right now. */
+ * values is supposed to be blocked in ocfs2_inode_lock right now. */
static void __ocfs2_stuff_meta_lvb(struct inode *inode)
{
struct ocfs2_inode_info *oi = OCFS2_I(inode);
- struct ocfs2_lock_res *lockres = &oi->ip_meta_lockres;
+ struct ocfs2_lock_res *lockres = &oi->ip_inode_lockres;
struct ocfs2_meta_lvb *lvb;
mlog_entry_void();
@@ -1496,7 +1667,7 @@ static void ocfs2_unpack_timespec(struct timespec *spec,
static void ocfs2_refresh_inode_from_lvb(struct inode *inode)
{
struct ocfs2_inode_info *oi = OCFS2_I(inode);
- struct ocfs2_lock_res *lockres = &oi->ip_meta_lockres;
+ struct ocfs2_lock_res *lockres = &oi->ip_inode_lockres;
struct ocfs2_meta_lvb *lvb;
mlog_entry_void();
@@ -1604,12 +1775,12 @@ static inline void ocfs2_complete_lock_res_refresh(struct ocfs2_lock_res *lockre
}
/* may or may not return a bh if it went to disk. */
-static int ocfs2_meta_lock_update(struct inode *inode,
+static int ocfs2_inode_lock_update(struct inode *inode,
struct buffer_head **bh)
{
int status = 0;
struct ocfs2_inode_info *oi = OCFS2_I(inode);
- struct ocfs2_lock_res *lockres = &oi->ip_meta_lockres;
+ struct ocfs2_lock_res *lockres = &oi->ip_inode_lockres;
struct ocfs2_dinode *fe;
struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
@@ -1721,7 +1892,7 @@ static int ocfs2_assign_bh(struct inode *inode,
* returns < 0 error if the callback will never be called, otherwise
* the result of the lock will be communicated via the callback.
*/
-int ocfs2_meta_lock_full(struct inode *inode,
+int ocfs2_inode_lock_full(struct inode *inode,
struct buffer_head **ret_bh,
int ex,
int arg_flags)
@@ -1756,7 +1927,7 @@ int ocfs2_meta_lock_full(struct inode *inode,
wait_event(osb->recovery_event,
ocfs2_node_map_is_empty(osb, &osb->recovery_map));
- lockres = &OCFS2_I(inode)->ip_meta_lockres;
+ lockres = &OCFS2_I(inode)->ip_inode_lockres;
level = ex ? LKM_EXMODE : LKM_PRMODE;
dlm_flags = 0;
if (arg_flags & OCFS2_META_LOCK_NOQUEUE)
@@ -1795,11 +1966,11 @@ local:
}
/* This is fun. The caller may want a bh back, or it may
- * not. ocfs2_meta_lock_update definitely wants one in, but
+ * not. ocfs2_inode_lock_update definitely wants one in, but
* may or may not read one, depending on what's in the
* LVB. The result of all of this is that we've *only* gone to
* disk if we have to, so the complexity is worthwhile. */
- status = ocfs2_meta_lock_update(inode, &local_bh);
+ status = ocfs2_inode_lock_update(inode, &local_bh);
if (status < 0) {
if (status != -ENOENT)
mlog_errno(status);
@@ -1821,7 +1992,7 @@ bail:
*ret_bh = NULL;
}
if (acquired)
- ocfs2_meta_unlock(inode, ex);
+ ocfs2_inode_unlock(inode, ex);
}
if (local_bh)
@@ -1832,19 +2003,20 @@ bail:
}
/*
- * This is working around a lock inversion between tasks acquiring DLM locks
- * while holding a page lock and the vote thread which blocks dlm lock acquiry
- * while acquiring page locks.
+ * This is working around a lock inversion between tasks acquiring DLM
+ * locks while holding a page lock and the downconvert thread which
+ * blocks dlm lock acquiry while acquiring page locks.
*
* ** These _with_page variantes are only intended to be called from aop
* methods that hold page locks and return a very specific *positive* error
* code that aop methods pass up to the VFS -- test for errors with != 0. **
*
- * The DLM is called such that it returns -EAGAIN if it would have blocked
- * waiting for the vote thread. In that case we unlock our page so the vote
- * thread can make progress. Once we've done this we have to return
- * AOP_TRUNCATED_PAGE so the aop method that called us can bubble that back up
- * into the VFS who will then immediately retry the aop call.
+ * The DLM is called such that it returns -EAGAIN if it would have
+ * blocked waiting for the downconvert thread. In that case we unlock
+ * our page so the downconvert thread can make progress. Once we've
+ * done this we have to return AOP_TRUNCATED_PAGE so the aop method
+ * that called us can bubble that back up into the VFS who will then
+ * immediately retry the aop call.
*
* We do a blocking lock and immediate unlock before returning, though, so that
* the lock has a great chance of being cached on this node by the time the VFS
@@ -1852,32 +2024,32 @@ bail:
* ping locks back and forth, but that's a risk we're willing to take to avoid
* the lock inversion simply.
*/
-int ocfs2_meta_lock_with_page(struct inode *inode,
+int ocfs2_inode_lock_with_page(struct inode *inode,
struct buffer_head **ret_bh,
int ex,
struct page *page)
{
int ret;
- ret = ocfs2_meta_lock_full(inode, ret_bh, ex, OCFS2_LOCK_NONBLOCK);
+ ret = ocfs2_inode_lock_full(inode, ret_bh, ex, OCFS2_LOCK_NONBLOCK);
if (ret == -EAGAIN) {
unlock_page(page);
- if (ocfs2_meta_lock(inode, ret_bh, ex) == 0)
- ocfs2_meta_unlock(inode, ex);
+ if (ocfs2_inode_lock(inode, ret_bh, ex) == 0)
+ ocfs2_inode_unlock(inode, ex);
ret = AOP_TRUNCATED_PAGE;
}
return ret;
}
-int ocfs2_meta_lock_atime(struct inode *inode,
+int ocfs2_inode_lock_atime(struct inode *inode,
struct vfsmount *vfsmnt,
int *level)
{
int ret;
mlog_entry_void();
- ret = ocfs2_meta_lock(inode, NULL, 0);
+ ret = ocfs2_inode_lock(inode, NULL, 0);
if (ret < 0) {
mlog_errno(ret);
return ret;
@@ -1890,8 +2062,8 @@ int ocfs2_meta_lock_atime(struct inode *inode,
if (ocfs2_should_update_atime(inode, vfsmnt)) {
struct buffer_head *bh = NULL;
- ocfs2_meta_unlock(inode, 0);
- ret = ocfs2_meta_lock(inode, &bh, 1);
+ ocfs2_inode_unlock(inode, 0);
+ ret = ocfs2_inode_lock(inode, &bh, 1);
if (ret < 0) {
mlog_errno(ret);
return ret;
@@ -1908,11 +2080,11 @@ int ocfs2_meta_lock_atime(struct inode *inode,
return ret;
}
-void ocfs2_meta_unlock(struct inode *inode,
+void ocfs2_inode_unlock(struct inode *inode,
int ex)
{
int level = ex ? LKM_EXMODE : LKM_PRMODE;
- struct ocfs2_lock_res *lockres = &OCFS2_I(inode)->ip_meta_lockres;
+ struct ocfs2_lock_res *lockres = &OCFS2_I(inode)->ip_inode_lockres;
struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
mlog_entry_void();
@@ -2320,11 +2492,11 @@ int ocfs2_dlm_init(struct ocfs2_super *osb)
goto bail;
}
- /* launch vote thread */
- osb->vote_task = kthread_run(ocfs2_vote_thread, osb, "ocfs2vote");
- if (IS_ERR(osb->vote_task)) {
- status = PTR_ERR(osb->vote_task);
- osb->vote_task = NULL;
+ /* launch downconvert thread */
+ osb->dc_task = kthread_run(ocfs2_downconvert_thread, osb, "ocfs2dc");
+ if (IS_ERR(osb->dc_task)) {
+ status = PTR_ERR(osb->dc_task);
+ osb->dc_task = NULL;
mlog_errno(status);
goto bail;
}
@@ -2353,8 +2525,8 @@ local:
bail:
if (status < 0) {
ocfs2_dlm_shutdown_debug(osb);
- if (osb->vote_task)
- kthread_stop(osb->vote_task);
+ if (osb->dc_task)
+ kthread_stop(osb->dc_task);
}
mlog_exit(status);
@@ -2369,9 +2541,9 @@ void ocfs2_dlm_shutdown(struct ocfs2_super *osb)
ocfs2_drop_osb_locks(osb);
- if (osb->vote_task) {
- kthread_stop(osb->vote_task);
- osb->vote_task = NULL;
+ if (osb->dc_task) {
+ kthread_stop(osb->dc_task);
+ osb->dc_task = NULL;
}
ocfs2_lock_res_free(&osb->osb_super_lockres);
@@ -2527,7 +2699,7 @@ out:
/* Mark the lockres as being dropped. It will no longer be
* queued if blocking, but we still may have to wait on it
- * being dequeued from the vote thread before we can consider
+ * being dequeued from the downconvert thread before we can consider
* it safe to drop.
*
* You can *not* attempt to call cluster_lock on this lockres anymore. */
@@ -2590,14 +2762,7 @@ int ocfs2_drop_inode_locks(struct inode *inode)
status = err;
err = ocfs2_drop_lock(OCFS2_SB(inode->i_sb),
- &OCFS2_I(inode)->ip_data_lockres);
- if (err < 0)
- mlog_errno(err);
- if (err < 0 && !status)
- status = err;
-
- err = ocfs2_drop_lock(OCFS2_SB(inode->i_sb),
- &OCFS2_I(inode)->ip_meta_lockres);
+ &OCFS2_I(inode)->ip_inode_lockres);
if (err < 0)
mlog_errno(err);
if (err < 0 && !status)
@@ -2850,6 +3015,9 @@ static int ocfs2_data_convert_worker(struct ocfs2_lock_res *lockres,
inode = ocfs2_lock_res_inode(lockres);
mapping = inode->i_mapping;
+ if (S_ISREG(inode->i_mode))
+ goto out;
+
/*
* We need this before the filemap_fdatawrite() so that it can
* transfer the dirty bit from the PTE to the
@@ -2875,6 +3043,7 @@ static int ocfs2_data_convert_worker(struct ocfs2_lock_res *lockres,
filemap_fdatawait(mapping);
}
+out:
return UNBLOCK_CONTINUE;
}
@@ -2903,7 +3072,7 @@ static void ocfs2_set_meta_lvb(struct ocfs2_lock_res *lockres)
/*
* Does the final reference drop on our dentry lock. Right now this
- * happens in the vote thread, but we could choose to simplify the
+ * happens in the downconvert thread, but we could choose to simplify the
* dlmglue API and push these off to the ocfs2_wq in the future.
*/
static void ocfs2_dentry_post_unlock(struct ocfs2_super *osb,
@@ -3042,7 +3211,7 @@ void ocfs2_process_blocked_lock(struct ocfs2_super *osb,
mlog(0, "lockres %s blocked.\n", lockres->l_name);
/* Detect whether a lock has been marked as going away while
- * the vote thread was processing other things. A lock can
+ * the downconvert thread was processing other things. A lock can
* still be marked with OCFS2_LOCK_FREEING after this check,
* but short circuiting here will still save us some
* performance. */
@@ -3091,13 +3260,104 @@ static void ocfs2_schedule_blocked_lock(struct ocfs2_super *osb,
lockres_or_flags(lockres, OCFS2_LOCK_QUEUED);
- spin_lock(&osb->vote_task_lock);
+ spin_lock(&osb->dc_task_lock);
if (list_empty(&lockres->l_blocked_list)) {
list_add_tail(&lockres->l_blocked_list,
&osb->blocked_lock_list);
osb->blocked_lock_count++;
}
- spin_unlock(&osb->vote_task_lock);
+ spin_unlock(&osb->dc_task_lock);
+
+ mlog_exit_void();
+}
+
+static void ocfs2_downconvert_thread_do_work(struct ocfs2_super *osb)
+{
+ unsigned long processed;
+ struct ocfs2_lock_res *lockres;
+
+ mlog_entry_void();
+
+ spin_lock(&osb->dc_task_lock);
+ /* grab this early so we know to try again if a state change and
+ * wake happens part-way through our work */
+ osb->dc_work_sequence = osb->dc_wake_sequence;
+
+ processed = osb->blocked_lock_count;
+ while (processed) {
+ BUG_ON(list_empty(&osb->blocked_lock_list));
+
+ lockres = list_entry(osb->blocked_lock_list.next,
+ struct ocfs2_lock_res, l_blocked_list);
+ list_del_init(&lockres->l_blocked_list);
+ osb->blocked_lock_count--;
+ spin_unlock(&osb->dc_task_lock);
+
+ BUG_ON(!processed);
+ processed--;
+
+ ocfs2_process_blocked_lock(osb, lockres);
+
+ spin_lock(&osb->dc_task_lock);
+ }
+ spin_unlock(&osb->dc_task_lock);
mlog_exit_void();
}
+
+static int ocfs2_downconvert_thread_lists_empty(struct ocfs2_super *osb)
+{
+ int empty = 0;
+
+ spin_lock(&osb->dc_task_lock);
+ if (list_empty(&osb->blocked_lock_list))
+ empty = 1;
+
+ spin_unlock(&osb->dc_task_lock);
+ return empty;
+}
+
+static int ocfs2_downconvert_thread_should_wake(struct ocfs2_super *osb)
+{
+ int should_wake = 0;
+
+ spin_lock(&osb->dc_task_lock);
+ if (osb->dc_work_sequence != osb->dc_wake_sequence)
+ should_wake = 1;
+ spin_unlock(&osb->dc_task_lock);
+
+ return should_wake;
+}
+
+int ocfs2_downconvert_thread(void *arg)
+{
+ int status = 0;
+ struct ocfs2_super *osb = arg;
+
+ /* only quit once we've been asked to stop and there is no more
+ * work available */
+ while (!(kthread_should_stop() &&
+ ocfs2_downconvert_thread_lists_empty(osb))) {
+
+ wait_event_interruptible(osb->dc_event,
+ ocfs2_downconvert_thread_should_wake(osb) ||
+ kthread_should_stop());
+
+ mlog(0, "downconvert_thread: awoken\n");
+
+ ocfs2_downconvert_thread_do_work(osb);
+ }
+
+ osb->dc_task = NULL;
+ return status;
+}
+
+void ocfs2_wake_downconvert_thread(struct ocfs2_super *osb)
+{
+ spin_lock(&osb->dc_task_lock);
+ /* make sure the voting thread gets a swipe at whatever changes
+ * the caller may have made to the voting state */
+ osb->dc_wake_sequence++;
+ spin_unlock(&osb->dc_task_lock);
+ wake_up(&osb->dc_event);
+}