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-rw-r--r--fs/locks.c99
1 files changed, 67 insertions, 32 deletions
diff --git a/fs/locks.c b/fs/locks.c
index 528fedfda15e..653faabb07f4 100644
--- a/fs/locks.c
+++ b/fs/locks.c
@@ -203,11 +203,11 @@ static struct kmem_cache *flctx_cache __read_mostly;
static struct kmem_cache *filelock_cache __read_mostly;
static struct file_lock_context *
-locks_get_lock_context(struct inode *inode)
+locks_get_lock_context(struct inode *inode, int type)
{
struct file_lock_context *new;
- if (likely(inode->i_flctx))
+ if (likely(inode->i_flctx) || type == F_UNLCK)
goto out;
new = kmem_cache_alloc(flctx_cache, GFP_KERNEL);
@@ -223,14 +223,7 @@ locks_get_lock_context(struct inode *inode)
* Assign the pointer if it's not already assigned. If it is, then
* free the context we just allocated.
*/
- spin_lock(&inode->i_lock);
- if (likely(!inode->i_flctx)) {
- inode->i_flctx = new;
- new = NULL;
- }
- spin_unlock(&inode->i_lock);
-
- if (new)
+ if (cmpxchg(&inode->i_flctx, NULL, new))
kmem_cache_free(flctx_cache, new);
out:
return inode->i_flctx;
@@ -276,8 +269,10 @@ void locks_release_private(struct file_lock *fl)
}
if (fl->fl_lmops) {
- if (fl->fl_lmops->lm_put_owner)
- fl->fl_lmops->lm_put_owner(fl);
+ if (fl->fl_lmops->lm_put_owner) {
+ fl->fl_lmops->lm_put_owner(fl->fl_owner);
+ fl->fl_owner = NULL;
+ }
fl->fl_lmops = NULL;
}
}
@@ -333,7 +328,7 @@ void locks_copy_conflock(struct file_lock *new, struct file_lock *fl)
if (fl->fl_lmops) {
if (fl->fl_lmops->lm_get_owner)
- fl->fl_lmops->lm_get_owner(new, fl);
+ fl->fl_lmops->lm_get_owner(fl->fl_owner);
}
}
EXPORT_SYMBOL(locks_copy_conflock);
@@ -592,11 +587,15 @@ posix_owner_key(struct file_lock *fl)
static void locks_insert_global_blocked(struct file_lock *waiter)
{
+ lockdep_assert_held(&blocked_lock_lock);
+
hash_add(blocked_hash, &waiter->fl_link, posix_owner_key(waiter));
}
static void locks_delete_global_blocked(struct file_lock *waiter)
{
+ lockdep_assert_held(&blocked_lock_lock);
+
hash_del(&waiter->fl_link);
}
@@ -730,7 +729,7 @@ static int posix_locks_conflict(struct file_lock *caller_fl, struct file_lock *s
/* POSIX locks owned by the same process do not conflict with
* each other.
*/
- if (!IS_POSIX(sys_fl) || posix_same_owner(caller_fl, sys_fl))
+ if (posix_same_owner(caller_fl, sys_fl))
return (0);
/* Check whether they overlap */
@@ -748,7 +747,7 @@ static int flock_locks_conflict(struct file_lock *caller_fl, struct file_lock *s
/* FLOCK locks referring to the same filp do not conflict with
* each other.
*/
- if (!IS_FLOCK(sys_fl) || (caller_fl->fl_file == sys_fl->fl_file))
+ if (caller_fl->fl_file == sys_fl->fl_file)
return (0);
if ((caller_fl->fl_type & LOCK_MAND) || (sys_fl->fl_type & LOCK_MAND))
return 0;
@@ -838,6 +837,8 @@ static int posix_locks_deadlock(struct file_lock *caller_fl,
{
int i = 0;
+ lockdep_assert_held(&blocked_lock_lock);
+
/*
* This deadlock detector can't reasonably detect deadlocks with
* FL_OFDLCK locks, since they aren't owned by a process, per-se.
@@ -871,9 +872,12 @@ static int flock_lock_file(struct file *filp, struct file_lock *request)
bool found = false;
LIST_HEAD(dispose);
- ctx = locks_get_lock_context(inode);
- if (!ctx)
- return -ENOMEM;
+ ctx = locks_get_lock_context(inode, request->fl_type);
+ if (!ctx) {
+ if (request->fl_type != F_UNLCK)
+ return -ENOMEM;
+ return (request->fl_flags & FL_EXISTS) ? -ENOENT : 0;
+ }
if (!(request->fl_flags & FL_ACCESS) && (request->fl_type != F_UNLCK)) {
new_fl = locks_alloc_lock();
@@ -939,9 +943,9 @@ static int __posix_lock_file(struct inode *inode, struct file_lock *request, str
bool added = false;
LIST_HEAD(dispose);
- ctx = locks_get_lock_context(inode);
+ ctx = locks_get_lock_context(inode, request->fl_type);
if (!ctx)
- return -ENOMEM;
+ return (request->fl_type == F_UNLCK) ? 0 : -ENOMEM;
/*
* We may need two file_lock structures for this operation,
@@ -964,8 +968,6 @@ static int __posix_lock_file(struct inode *inode, struct file_lock *request, str
*/
if (request->fl_type != F_UNLCK) {
list_for_each_entry(fl, &ctx->flc_posix, fl_list) {
- if (!IS_POSIX(fl))
- continue;
if (!posix_locks_conflict(request, fl))
continue;
if (conflock)
@@ -1388,9 +1390,8 @@ any_leases_conflict(struct inode *inode, struct file_lock *breaker)
int __break_lease(struct inode *inode, unsigned int mode, unsigned int type)
{
int error = 0;
- struct file_lock *new_fl;
struct file_lock_context *ctx = inode->i_flctx;
- struct file_lock *fl;
+ struct file_lock *new_fl, *fl, *tmp;
unsigned long break_time;
int want_write = (mode & O_ACCMODE) != O_RDONLY;
LIST_HEAD(dispose);
@@ -1420,7 +1421,7 @@ int __break_lease(struct inode *inode, unsigned int mode, unsigned int type)
break_time++; /* so that 0 means no break time */
}
- list_for_each_entry(fl, &ctx->flc_lease, fl_list) {
+ list_for_each_entry_safe(fl, tmp, &ctx->flc_lease, fl_list) {
if (!leases_conflict(fl, new_fl))
continue;
if (want_write) {
@@ -1606,7 +1607,8 @@ generic_add_lease(struct file *filp, long arg, struct file_lock **flp, void **pr
lease = *flp;
trace_generic_add_lease(inode, lease);
- ctx = locks_get_lock_context(inode);
+ /* Note that arg is never F_UNLCK here */
+ ctx = locks_get_lock_context(inode, arg);
if (!ctx)
return -ENOMEM;
@@ -2556,15 +2558,10 @@ static void lock_get_status(struct seq_file *f, struct file_lock *fl,
: (fl->fl_type == F_WRLCK) ? "WRITE" : "READ ");
}
if (inode) {
-#ifdef WE_CAN_BREAK_LSLK_NOW
- seq_printf(f, "%d %s:%ld ", fl_pid,
- inode->i_sb->s_id, inode->i_ino);
-#else
- /* userspace relies on this representation of dev_t ;-( */
+ /* userspace relies on this representation of dev_t */
seq_printf(f, "%d %02x:%02x:%ld ", fl_pid,
MAJOR(inode->i_sb->s_dev),
MINOR(inode->i_sb->s_dev), inode->i_ino);
-#endif
} else {
seq_printf(f, "%d <none>:0 ", fl_pid);
}
@@ -2593,6 +2590,44 @@ static int locks_show(struct seq_file *f, void *v)
return 0;
}
+static void __show_fd_locks(struct seq_file *f,
+ struct list_head *head, int *id,
+ struct file *filp, struct files_struct *files)
+{
+ struct file_lock *fl;
+
+ list_for_each_entry(fl, head, fl_list) {
+
+ if (filp != fl->fl_file)
+ continue;
+ if (fl->fl_owner != files &&
+ fl->fl_owner != filp)
+ continue;
+
+ (*id)++;
+ seq_puts(f, "lock:\t");
+ lock_get_status(f, fl, *id, "");
+ }
+}
+
+void show_fd_locks(struct seq_file *f,
+ struct file *filp, struct files_struct *files)
+{
+ struct inode *inode = file_inode(filp);
+ struct file_lock_context *ctx;
+ int id = 0;
+
+ ctx = inode->i_flctx;
+ if (!ctx)
+ return;
+
+ spin_lock(&ctx->flc_lock);
+ __show_fd_locks(f, &ctx->flc_flock, &id, filp, files);
+ __show_fd_locks(f, &ctx->flc_posix, &id, filp, files);
+ __show_fd_locks(f, &ctx->flc_lease, &id, filp, files);
+ spin_unlock(&ctx->flc_lock);
+}
+
static void *locks_start(struct seq_file *f, loff_t *pos)
__acquires(&blocked_lock_lock)
{
Copyright © 1996 – 2023 Jason A. Donenfeld. All Rights Reverse Engineered.