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locks: convert lease handling to file_lock_context
Signed-off-by: Jeff Layton <jlayton@primarydata.com> Acked-by: Christoph Hellwig <hch@lst.de>
This commit is contained in:
Jeff Layton
Jeff Layton
parent
bd61e0a9c8
commit
8634b51f6c
256
fs/locks.c
256
fs/locks.c
@ -216,6 +216,7 @@ locks_get_lock_context(struct inode *inode)
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INIT_LIST_HEAD(&new->flc_flock);
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INIT_LIST_HEAD(&new->flc_posix);
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INIT_LIST_HEAD(&new->flc_lease);
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/*
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* Assign the pointer if it's not already assigned. If it is, then
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@ -240,6 +241,7 @@ locks_free_lock_context(struct file_lock_context *ctx)
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if (ctx) {
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WARN_ON_ONCE(!list_empty(&ctx->flc_flock));
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WARN_ON_ONCE(!list_empty(&ctx->flc_posix));
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WARN_ON_ONCE(!list_empty(&ctx->flc_lease));
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kmem_cache_free(flctx_cache, ctx);
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}
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}
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@ -677,22 +679,6 @@ static void locks_wake_up_blocks(struct file_lock *blocker)
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spin_unlock(&blocked_lock_lock);
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}
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/* Insert file lock fl into an inode's lock list at the position indicated
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* by pos. At the same time add the lock to the global file lock list.
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*
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* Must be called with the i_lock held!
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*/
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static void locks_insert_lock(struct file_lock **pos, struct file_lock *fl)
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{
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fl->fl_nspid = get_pid(task_tgid(current));
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/* insert into file's list */
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fl->fl_next = *pos;
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*pos = fl;
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locks_insert_global_locks(fl);
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}
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static void
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locks_insert_lock_ctx(struct file_lock *fl, struct list_head *before)
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{
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@ -701,61 +687,26 @@ locks_insert_lock_ctx(struct file_lock *fl, struct list_head *before)
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locks_insert_global_locks(fl);
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}
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/**
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* locks_delete_lock - Delete a lock and then free it.
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* @thisfl_p: pointer that points to the fl_next field of the previous
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* inode->i_flock list entry
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*
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* Unlink a lock from all lists and free the namespace reference, but don't
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* free it yet. Wake up processes that are blocked waiting for this lock and
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* notify the FS that the lock has been cleared.
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*
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* Must be called with the i_lock held!
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*/
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static void locks_unlink_lock(struct file_lock **thisfl_p)
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static void
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locks_unlink_lock_ctx(struct file_lock *fl)
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{
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struct file_lock *fl = *thisfl_p;
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locks_delete_global_locks(fl);
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*thisfl_p = fl->fl_next;
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fl->fl_next = NULL;
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list_del_init(&fl->fl_list);
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if (fl->fl_nspid) {
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put_pid(fl->fl_nspid);
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fl->fl_nspid = NULL;
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}
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locks_wake_up_blocks(fl);
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}
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/*
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* Unlink a lock from all lists and free it.
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*
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* Must be called with i_lock held!
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*/
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static void locks_delete_lock(struct file_lock **thisfl_p,
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struct list_head *dispose)
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{
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struct file_lock *fl = *thisfl_p;
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locks_unlink_lock(thisfl_p);
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if (dispose)
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list_add(&fl->fl_list, dispose);
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else
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locks_free_lock(fl);
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}
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static void
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locks_delete_lock_ctx(struct file_lock *fl, struct list_head *dispose)
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{
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locks_delete_global_locks(fl);
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if (fl->fl_nspid) {
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put_pid(fl->fl_nspid);
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fl->fl_nspid = NULL;
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}
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locks_wake_up_blocks(fl);
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list_move(&fl->fl_list, dispose);
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locks_unlink_lock_ctx(fl);
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if (dispose)
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list_add(&fl->fl_list, dispose);
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else
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locks_free_lock(fl);
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}
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/* Determine if lock sys_fl blocks lock caller_fl. Common functionality
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@ -1376,7 +1327,7 @@ int lease_modify(struct file_lock **before, int arg, struct list_head *dispose)
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printk(KERN_ERR "locks_delete_lock: fasync == %p\n", fl->fl_fasync);
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fl->fl_fasync = NULL;
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}
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locks_delete_lock(before, dispose);
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locks_delete_lock_ctx(fl, dispose);
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}
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return 0;
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}
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@ -1392,20 +1343,17 @@ static bool past_time(unsigned long then)
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static void time_out_leases(struct inode *inode, struct list_head *dispose)
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{
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struct file_lock **before;
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struct file_lock *fl;
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struct file_lock_context *ctx = inode->i_flctx;
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struct file_lock *fl, *tmp;
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lockdep_assert_held(&inode->i_lock);
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before = &inode->i_flock;
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while ((fl = *before) && IS_LEASE(fl) && lease_breaking(fl)) {
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list_for_each_entry_safe(fl, tmp, &ctx->flc_lease, fl_list) {
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trace_time_out_leases(inode, fl);
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if (past_time(fl->fl_downgrade_time))
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lease_modify(before, F_RDLCK, dispose);
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lease_modify(&fl, F_RDLCK, dispose);
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if (past_time(fl->fl_break_time))
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lease_modify(before, F_UNLCK, dispose);
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if (fl == *before) /* lease_modify may have freed fl */
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before = &fl->fl_next;
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lease_modify(&fl, F_UNLCK, dispose);
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}
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}
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@ -1419,11 +1367,12 @@ static bool leases_conflict(struct file_lock *lease, struct file_lock *breaker)
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static bool
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any_leases_conflict(struct inode *inode, struct file_lock *breaker)
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{
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struct file_lock_context *ctx = inode->i_flctx;
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struct file_lock *fl;
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lockdep_assert_held(&inode->i_lock);
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for (fl = inode->i_flock ; fl && IS_LEASE(fl); fl = fl->fl_next) {
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list_for_each_entry(fl, &ctx->flc_lease, fl_list) {
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if (leases_conflict(fl, breaker))
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return true;
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}
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@ -1447,7 +1396,8 @@ int __break_lease(struct inode *inode, unsigned int mode, unsigned int type)
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{
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int error = 0;
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struct file_lock *new_fl;
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struct file_lock *fl, **before;
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struct file_lock_context *ctx = inode->i_flctx;
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struct file_lock *fl;
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unsigned long break_time;
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int want_write = (mode & O_ACCMODE) != O_RDONLY;
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LIST_HEAD(dispose);
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@ -1457,6 +1407,12 @@ int __break_lease(struct inode *inode, unsigned int mode, unsigned int type)
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return PTR_ERR(new_fl);
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new_fl->fl_flags = type;
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/* typically we will check that ctx is non-NULL before calling */
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if (!ctx) {
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WARN_ON_ONCE(1);
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return error;
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}
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spin_lock(&inode->i_lock);
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time_out_leases(inode, &dispose);
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@ -1471,9 +1427,7 @@ int __break_lease(struct inode *inode, unsigned int mode, unsigned int type)
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break_time++; /* so that 0 means no break time */
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}
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for (before = &inode->i_flock;
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((fl = *before) != NULL) && IS_LEASE(fl);
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before = &fl->fl_next) {
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list_for_each_entry(fl, &ctx->flc_lease, fl_list) {
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if (!leases_conflict(fl, new_fl))
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continue;
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if (want_write) {
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@ -1482,17 +1436,16 @@ int __break_lease(struct inode *inode, unsigned int mode, unsigned int type)
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fl->fl_flags |= FL_UNLOCK_PENDING;
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fl->fl_break_time = break_time;
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} else {
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if (lease_breaking(inode->i_flock))
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if (lease_breaking(fl))
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continue;
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fl->fl_flags |= FL_DOWNGRADE_PENDING;
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fl->fl_downgrade_time = break_time;
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}
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if (fl->fl_lmops->lm_break(fl))
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locks_delete_lock(before, &dispose);
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locks_delete_lock_ctx(fl, &dispose);
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}
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fl = inode->i_flock;
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if (!fl || !IS_LEASE(fl))
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if (list_empty(&ctx->flc_lease))
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goto out;
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if (mode & O_NONBLOCK) {
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@ -1502,12 +1455,13 @@ int __break_lease(struct inode *inode, unsigned int mode, unsigned int type)
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}
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restart:
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break_time = inode->i_flock->fl_break_time;
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fl = list_first_entry(&ctx->flc_lease, struct file_lock, fl_list);
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break_time = fl->fl_break_time;
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if (break_time != 0)
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break_time -= jiffies;
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if (break_time == 0)
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break_time++;
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locks_insert_block(inode->i_flock, new_fl);
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locks_insert_block(fl, new_fl);
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trace_break_lease_block(inode, new_fl);
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spin_unlock(&inode->i_lock);
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locks_dispose_list(&dispose);
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@ -1525,10 +1479,8 @@ restart:
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time_out_leases(inode, &dispose);
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if (any_leases_conflict(inode, new_fl))
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goto restart;
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error = 0;
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}
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out:
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spin_unlock(&inode->i_lock);
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locks_dispose_list(&dispose);
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@ -1550,13 +1502,17 @@ EXPORT_SYMBOL(__break_lease);
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void lease_get_mtime(struct inode *inode, struct timespec *time)
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{
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bool has_lease = false;
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struct file_lock *flock;
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struct file_lock_context *ctx = inode->i_flctx;
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struct file_lock *fl;
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if (inode->i_flock) {
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if (ctx && !list_empty_careful(&ctx->flc_lease)) {
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spin_lock(&inode->i_lock);
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flock = inode->i_flock;
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if (flock && IS_LEASE(flock) && (flock->fl_type == F_WRLCK))
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has_lease = true;
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if (!list_empty(&ctx->flc_lease)) {
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fl = list_first_entry(&ctx->flc_lease,
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struct file_lock, fl_list);
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if (fl->fl_type == F_WRLCK)
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has_lease = true;
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}
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spin_unlock(&inode->i_lock);
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}
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@ -1595,20 +1551,22 @@ int fcntl_getlease(struct file *filp)
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{
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struct file_lock *fl;
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struct inode *inode = file_inode(filp);
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struct file_lock_context *ctx = inode->i_flctx;
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int type = F_UNLCK;
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LIST_HEAD(dispose);
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spin_lock(&inode->i_lock);
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time_out_leases(file_inode(filp), &dispose);
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for (fl = file_inode(filp)->i_flock; fl && IS_LEASE(fl);
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fl = fl->fl_next) {
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if (fl->fl_file == filp) {
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if (ctx && !list_empty_careful(&ctx->flc_lease)) {
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spin_lock(&inode->i_lock);
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time_out_leases(file_inode(filp), &dispose);
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list_for_each_entry(fl, &ctx->flc_lease, fl_list) {
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if (fl->fl_file != filp)
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continue;
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type = target_leasetype(fl);
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break;
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}
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spin_unlock(&inode->i_lock);
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locks_dispose_list(&dispose);
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}
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spin_unlock(&inode->i_lock);
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locks_dispose_list(&dispose);
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return type;
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}
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@ -1641,9 +1599,10 @@ check_conflicting_open(const struct dentry *dentry, const long arg)
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static int
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generic_add_lease(struct file *filp, long arg, struct file_lock **flp, void **priv)
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{
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struct file_lock *fl, **before, **my_before = NULL, *lease;
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struct file_lock *fl, *my_fl = NULL, *lease;
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struct dentry *dentry = filp->f_path.dentry;
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struct inode *inode = dentry->d_inode;
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struct file_lock_context *ctx;
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bool is_deleg = (*flp)->fl_flags & FL_DELEG;
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int error;
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LIST_HEAD(dispose);
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@ -1651,6 +1610,10 @@ generic_add_lease(struct file *filp, long arg, struct file_lock **flp, void **pr
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lease = *flp;
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trace_generic_add_lease(inode, lease);
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ctx = locks_get_lock_context(inode);
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if (!ctx)
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return -ENOMEM;
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/*
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* In the delegation case we need mutual exclusion with
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* a number of operations that take the i_mutex. We trylock
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@ -1684,13 +1647,12 @@ generic_add_lease(struct file *filp, long arg, struct file_lock **flp, void **pr
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* except for this filp.
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*/
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error = -EAGAIN;
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for (before = &inode->i_flock;
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((fl = *before) != NULL) && IS_LEASE(fl);
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before = &fl->fl_next) {
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list_for_each_entry(fl, &ctx->flc_lease, fl_list) {
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if (fl->fl_file == filp) {
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my_before = before;
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my_fl = fl;
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continue;
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}
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/*
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* No exclusive leases if someone else has a lease on
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* this file:
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@ -1705,9 +1667,8 @@ generic_add_lease(struct file *filp, long arg, struct file_lock **flp, void **pr
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goto out;
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}
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if (my_before != NULL) {
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lease = *my_before;
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error = lease->fl_lmops->lm_change(my_before, arg, &dispose);
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if (my_fl != NULL) {
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error = lease->fl_lmops->lm_change(&my_fl, arg, &dispose);
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if (error)
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goto out;
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goto out_setup;
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@ -1717,7 +1678,7 @@ generic_add_lease(struct file *filp, long arg, struct file_lock **flp, void **pr
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if (!leases_enable)
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goto out;
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locks_insert_lock(before, lease);
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locks_insert_lock_ctx(lease, &ctx->flc_lease);
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/*
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* The check in break_lease() is lockless. It's possible for another
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* open to race in after we did the earlier check for a conflicting
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@ -1729,8 +1690,10 @@ generic_add_lease(struct file *filp, long arg, struct file_lock **flp, void **pr
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*/
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smp_mb();
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error = check_conflicting_open(dentry, arg);
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if (error)
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goto out_unlink;
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if (error) {
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locks_unlink_lock_ctx(lease);
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goto out;
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}
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out_setup:
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if (lease->fl_lmops->lm_setup)
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@ -1740,33 +1703,35 @@ out:
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locks_dispose_list(&dispose);
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if (is_deleg)
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mutex_unlock(&inode->i_mutex);
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if (!error && !my_before)
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if (!error && !my_fl)
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*flp = NULL;
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return error;
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out_unlink:
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locks_unlink_lock(before);
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goto out;
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}
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static int generic_delete_lease(struct file *filp)
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{
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int error = -EAGAIN;
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struct file_lock *fl, **before;
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struct file_lock *fl, *victim = NULL;
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struct dentry *dentry = filp->f_path.dentry;
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struct inode *inode = dentry->d_inode;
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struct file_lock_context *ctx = inode->i_flctx;
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LIST_HEAD(dispose);
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if (!ctx) {
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trace_generic_delete_lease(inode, NULL);
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return error;
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}
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spin_lock(&inode->i_lock);
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time_out_leases(inode, &dispose);
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for (before = &inode->i_flock;
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((fl = *before) != NULL) && IS_LEASE(fl);
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before = &fl->fl_next) {
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if (fl->fl_file == filp)
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list_for_each_entry(fl, &ctx->flc_lease, fl_list) {
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if (fl->fl_file == filp) {
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victim = fl;
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break;
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}
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}
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trace_generic_delete_lease(inode, fl);
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if (fl && IS_LEASE(fl))
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error = fl->fl_lmops->lm_change(before, F_UNLCK, &dispose);
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if (victim)
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error = fl->fl_lmops->lm_change(&victim, F_UNLCK, &dispose);
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spin_unlock(&inode->i_lock);
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locks_dispose_list(&dispose);
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return error;
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@ -2447,56 +2412,37 @@ locks_remove_flock(struct file *filp)
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fl.fl_ops->fl_release_private(&fl);
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}
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static void
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locks_remove_lease(struct file *filp)
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{
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struct inode *inode = file_inode(filp);
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struct file_lock_context *ctx = inode->i_flctx;
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struct file_lock *fl, *tmp;
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LIST_HEAD(dispose);
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if (!ctx || list_empty(&ctx->flc_lease))
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return;
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spin_lock(&inode->i_lock);
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list_for_each_entry_safe(fl, tmp, &ctx->flc_lease, fl_list)
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lease_modify(&fl, F_UNLCK, &dispose);
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spin_unlock(&inode->i_lock);
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locks_dispose_list(&dispose);
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}
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/*
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* This function is called on the last close of an open file.
|
||||
*/
|
||||
void locks_remove_file(struct file *filp)
|
||||
{
|
||||
struct inode * inode = file_inode(filp);
|
||||
struct file_lock *fl;
|
||||
struct file_lock **before;
|
||||
LIST_HEAD(dispose);
|
||||
|
||||
/* remove any OFD locks */
|
||||
locks_remove_posix(filp, filp);
|
||||
|
||||
/* remove flock locks */
|
||||
locks_remove_flock(filp);
|
||||
|
||||
if (!inode->i_flock)
|
||||
return;
|
||||
|
||||
spin_lock(&inode->i_lock);
|
||||
before = &inode->i_flock;
|
||||
|
||||
while ((fl = *before) != NULL) {
|
||||
if (fl->fl_file == filp) {
|
||||
if (IS_LEASE(fl)) {
|
||||
lease_modify(before, F_UNLCK, &dispose);
|
||||
continue;
|
||||
}
|
||||
|
||||
/*
|
||||
* There's a leftover lock on the list of a type that
|
||||
* we didn't expect to see. Most likely a classic
|
||||
* POSIX lock that ended up not getting released
|
||||
* properly, or that raced onto the list somehow. Log
|
||||
* some info about it and then just remove it from
|
||||
* the list.
|
||||
*/
|
||||
WARN(1, "leftover lock: dev=%u:%u ino=%lu type=%hhd flags=0x%x start=%lld end=%lld\n",
|
||||
MAJOR(inode->i_sb->s_dev),
|
||||
MINOR(inode->i_sb->s_dev), inode->i_ino,
|
||||
fl->fl_type, fl->fl_flags,
|
||||
fl->fl_start, fl->fl_end);
|
||||
|
||||
locks_delete_lock(before, &dispose);
|
||||
continue;
|
||||
}
|
||||
before = &fl->fl_next;
|
||||
}
|
||||
spin_unlock(&inode->i_lock);
|
||||
locks_dispose_list(&dispose);
|
||||
/* remove any leases */
|
||||
locks_remove_lease(filp);
|
||||
}
|
||||
|
||||
/**
|
||||
|
||||
@ -969,6 +969,7 @@ struct file_lock {
|
||||
struct file_lock_context {
|
||||
struct list_head flc_flock;
|
||||
struct list_head flc_posix;
|
||||
struct list_head flc_lease;
|
||||
};
|
||||
|
||||
/* The following constant reflects the upper bound of the file/locking space */
|
||||
@ -1990,7 +1991,7 @@ static inline int break_lease(struct inode *inode, unsigned int mode)
|
||||
* end up racing with tasks trying to set a new lease on this file.
|
||||
*/
|
||||
smp_mb();
|
||||
if (inode->i_flock)
|
||||
if (inode->i_flctx && !list_empty_careful(&inode->i_flctx->flc_lease))
|
||||
return __break_lease(inode, mode, FL_LEASE);
|
||||
return 0;
|
||||
}
|
||||
@ -2003,7 +2004,7 @@ static inline int break_deleg(struct inode *inode, unsigned int mode)
|
||||
* end up racing with tasks trying to set a new lease on this file.
|
||||
*/
|
||||
smp_mb();
|
||||
if (inode->i_flock)
|
||||
if (inode->i_flctx && !list_empty_careful(&inode->i_flctx->flc_lease))
|
||||
return __break_lease(inode, mode, FL_DELEG);
|
||||
return 0;
|
||||
}
|
||||
|
||||
Loading…
Reference in New Issue
Block a user