From c45198eda2794bb72601c9f96266d8b95db66dd5 Mon Sep 17 00:00:00 2001 From: Jeff Layton Date: Mon, 1 Sep 2014 07:12:07 -0400 Subject: locks: move freeing of leases outside of i_lock There was only one place where we still could free a file_lock while holding the i_lock -- lease_modify. Add a new list_head argument to the lm_change operation, pass in a private list when calling it, and fix those callers to dispose of the list once the lock has been dropped. Signed-off-by: Jeff Layton Reviewed-by: Christoph Hellwig --- fs/locks.c | 34 ++++++++++++++++++++++------------ 1 file changed, 22 insertions(+), 12 deletions(-) (limited to 'fs/locks.c') diff --git a/fs/locks.c b/fs/locks.c index eb463257f867..c0f789dfa655 100644 --- a/fs/locks.c +++ b/fs/locks.c @@ -1292,7 +1292,7 @@ static void lease_clear_pending(struct file_lock *fl, int arg) } /* We already had a lease on this file; just change its type */ -int lease_modify(struct file_lock **before, int arg) +int lease_modify(struct file_lock **before, int arg, struct list_head *dispose) { struct file_lock *fl = *before; int error = assign_type(fl, arg); @@ -1311,7 +1311,7 @@ int lease_modify(struct file_lock **before, int arg) printk(KERN_ERR "locks_delete_lock: fasync == %p\n", fl->fl_fasync); fl->fl_fasync = NULL; } - locks_delete_lock(before, NULL); + locks_delete_lock(before, dispose); } return 0; } @@ -1325,7 +1325,7 @@ static bool past_time(unsigned long then) return time_after(jiffies, then); } -static void time_out_leases(struct inode *inode) +static void time_out_leases(struct inode *inode, struct list_head *dispose) { struct file_lock **before; struct file_lock *fl; @@ -1336,9 +1336,9 @@ static void time_out_leases(struct inode *inode) while ((fl = *before) && IS_LEASE(fl) && lease_breaking(fl)) { trace_time_out_leases(inode, fl); if (past_time(fl->fl_downgrade_time)) - lease_modify(before, F_RDLCK); + lease_modify(before, F_RDLCK, dispose); if (past_time(fl->fl_break_time)) - lease_modify(before, F_UNLCK); + lease_modify(before, F_UNLCK, dispose); if (fl == *before) /* lease_modify may have freed fl */ before = &fl->fl_next; } @@ -1373,6 +1373,7 @@ int __break_lease(struct inode *inode, unsigned int mode, unsigned int type) int i_have_this_lease = 0; bool lease_conflict = false; int want_write = (mode & O_ACCMODE) != O_RDONLY; + LIST_HEAD(dispose); new_fl = lease_alloc(NULL, want_write ? F_WRLCK : F_RDLCK); if (IS_ERR(new_fl)) @@ -1381,7 +1382,7 @@ int __break_lease(struct inode *inode, unsigned int mode, unsigned int type) spin_lock(&inode->i_lock); - time_out_leases(inode); + time_out_leases(inode, &dispose); flock = inode->i_flock; if ((flock == NULL) || !IS_LEASE(flock)) @@ -1436,6 +1437,7 @@ restart: locks_insert_block(flock, new_fl); trace_break_lease_block(inode, new_fl); spin_unlock(&inode->i_lock); + locks_dispose_list(&dispose); error = wait_event_interruptible_timeout(new_fl->fl_wait, !new_fl->fl_next, break_time); spin_lock(&inode->i_lock); @@ -1443,7 +1445,7 @@ restart: locks_delete_block(new_fl); if (error >= 0) { if (error == 0) - time_out_leases(inode); + time_out_leases(inode, &dispose); /* * Wait for the next conflicting lease that has not been * broken yet @@ -1458,6 +1460,7 @@ restart: out: spin_unlock(&inode->i_lock); + locks_dispose_list(&dispose); locks_free_lock(new_fl); return error; } @@ -1522,9 +1525,10 @@ int fcntl_getlease(struct file *filp) struct file_lock *fl; struct inode *inode = file_inode(filp); int type = F_UNLCK; + LIST_HEAD(dispose); spin_lock(&inode->i_lock); - time_out_leases(file_inode(filp)); + time_out_leases(file_inode(filp), &dispose); for (fl = file_inode(filp)->i_flock; fl && IS_LEASE(fl); fl = fl->fl_next) { if (fl->fl_file == filp) { @@ -1533,6 +1537,7 @@ int fcntl_getlease(struct file *filp) } } spin_unlock(&inode->i_lock); + locks_dispose_list(&dispose); return type; } @@ -1570,6 +1575,7 @@ generic_add_lease(struct file *filp, long arg, struct file_lock **flp, void **pr struct inode *inode = dentry->d_inode; bool is_deleg = (*flp)->fl_flags & FL_DELEG; int error; + LIST_HEAD(dispose); lease = *flp; trace_generic_add_lease(inode, lease); @@ -1593,7 +1599,7 @@ generic_add_lease(struct file *filp, long arg, struct file_lock **flp, void **pr } spin_lock(&inode->i_lock); - time_out_leases(inode); + time_out_leases(inode, &dispose); error = check_conflicting_open(dentry, arg); if (error) goto out; @@ -1630,7 +1636,7 @@ generic_add_lease(struct file *filp, long arg, struct file_lock **flp, void **pr if (my_before != NULL) { lease = *my_before; - error = lease->fl_lmops->lm_change(my_before, arg); + error = lease->fl_lmops->lm_change(my_before, arg, &dispose); if (error) goto out; goto out_setup; @@ -1660,6 +1666,7 @@ out_setup: lease->fl_lmops->lm_setup(lease, priv); out: spin_unlock(&inode->i_lock); + locks_dispose_list(&dispose); if (is_deleg) mutex_unlock(&inode->i_mutex); if (!error && !my_before) @@ -1676,8 +1683,10 @@ static int generic_delete_lease(struct file *filp) struct file_lock *fl, **before; struct dentry *dentry = filp->f_path.dentry; struct inode *inode = dentry->d_inode; + LIST_HEAD(dispose); spin_lock(&inode->i_lock); + time_out_leases(inode, &dispose); for (before = &inode->i_flock; ((fl = *before) != NULL) && IS_LEASE(fl); before = &fl->fl_next) { @@ -1686,8 +1695,9 @@ static int generic_delete_lease(struct file *filp) } trace_generic_delete_lease(inode, fl); if (fl) - error = fl->fl_lmops->lm_change(before, F_UNLCK); + error = fl->fl_lmops->lm_change(before, F_UNLCK, &dispose); spin_unlock(&inode->i_lock); + locks_dispose_list(&dispose); return error; } @@ -2372,7 +2382,7 @@ void locks_remove_file(struct file *filp) while ((fl = *before) != NULL) { if (fl->fl_file == filp) { if (IS_LEASE(fl)) { - lease_modify(before, F_UNLCK); + lease_modify(before, F_UNLCK, &dispose); continue; } -- cgit