diff options
| -rw-r--r-- | fs/locks.c | 62 | ||||
| -rw-r--r-- | include/linux/fs.h | 4 | ||||
| -rw-r--r-- | include/trace/events/filelock.h | 35 |
3 files changed, 79 insertions, 22 deletions
diff --git a/fs/locks.c b/fs/locks.c index ec1e4a5df629..de87a3231789 100644 --- a/fs/locks.c +++ b/fs/locks.c @@ -1534,11 +1534,21 @@ static void time_out_leases(struct inode *inode, struct list_head *dispose) static bool leases_conflict(struct file_lock *lease, struct file_lock *breaker) { - if ((breaker->fl_flags & FL_LAYOUT) != (lease->fl_flags & FL_LAYOUT)) - return false; - if ((breaker->fl_flags & FL_DELEG) && (lease->fl_flags & FL_LEASE)) - return false; - return locks_conflict(breaker, lease); + bool rc; + + if ((breaker->fl_flags & FL_LAYOUT) != (lease->fl_flags & FL_LAYOUT)) { + rc = false; + goto trace; + } + if ((breaker->fl_flags & FL_DELEG) && (lease->fl_flags & FL_LEASE)) { + rc = false; + goto trace; + } + + rc = locks_conflict(breaker, lease); +trace: + trace_leases_conflict(rc, lease, breaker); + return rc; } static bool @@ -1753,10 +1763,10 @@ int fcntl_getlease(struct file *filp) } /** - * check_conflicting_open - see if the given dentry points to a file that has + * check_conflicting_open - see if the given file points to an inode that has * an existing open that would conflict with the * desired lease. - * @dentry: dentry to check + * @filp: file to check * @arg: type of lease that we're trying to acquire * @flags: current lock flags * @@ -1764,30 +1774,42 @@ int fcntl_getlease(struct file *filp) * conflict with the lease we're trying to set. */ static int -check_conflicting_open(const struct dentry *dentry, const long arg, int flags) +check_conflicting_open(struct file *filp, const long arg, int flags) { - int ret = 0; - struct inode *inode = dentry->d_inode; + struct inode *inode = locks_inode(filp); + int self_wcount = 0, self_rcount = 0; if (flags & FL_LAYOUT) return 0; - if ((arg == F_RDLCK) && inode_is_open_for_write(inode)) - return -EAGAIN; + if (arg == F_RDLCK) + return inode_is_open_for_write(inode) ? -EAGAIN : 0; + else if (arg != F_WRLCK) + return 0; - if ((arg == F_WRLCK) && ((d_count(dentry) > 1) || - (atomic_read(&inode->i_count) > 1))) - ret = -EAGAIN; + /* + * Make sure that only read/write count is from lease requestor. + * Note that this will result in denying write leases when i_writecount + * is negative, which is what we want. (We shouldn't grant write leases + * on files open for execution.) + */ + if (filp->f_mode & FMODE_WRITE) + self_wcount = 1; + else if (filp->f_mode & FMODE_READ) + self_rcount = 1; - return ret; + if (atomic_read(&inode->i_writecount) != self_wcount || + atomic_read(&inode->i_readcount) != self_rcount) + return -EAGAIN; + + return 0; } static int generic_add_lease(struct file *filp, long arg, struct file_lock **flp, void **priv) { struct file_lock *fl, *my_fl = NULL, *lease; - struct dentry *dentry = filp->f_path.dentry; - struct inode *inode = dentry->d_inode; + struct inode *inode = locks_inode(filp); struct file_lock_context *ctx; bool is_deleg = (*flp)->fl_flags & FL_DELEG; int error; @@ -1822,7 +1844,7 @@ generic_add_lease(struct file *filp, long arg, struct file_lock **flp, void **pr percpu_down_read(&file_rwsem); spin_lock(&ctx->flc_lock); time_out_leases(inode, &dispose); - error = check_conflicting_open(dentry, arg, lease->fl_flags); + error = check_conflicting_open(filp, arg, lease->fl_flags); if (error) goto out; @@ -1879,7 +1901,7 @@ generic_add_lease(struct file *filp, long arg, struct file_lock **flp, void **pr * precedes these checks. */ smp_mb(); - error = check_conflicting_open(dentry, arg, lease->fl_flags); + error = check_conflicting_open(filp, arg, lease->fl_flags); if (error) { locks_unlink_lock_ctx(lease); goto out; diff --git a/include/linux/fs.h b/include/linux/fs.h index c564cf3f48d9..4fb399b77327 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -694,7 +694,7 @@ struct inode { atomic_t i_count; atomic_t i_dio_count; atomic_t i_writecount; -#ifdef CONFIG_IMA +#if defined(CONFIG_IMA) || defined(CONFIG_FILE_LOCKING) atomic_t i_readcount; /* struct files open RO */ #endif union { @@ -2890,7 +2890,7 @@ static inline bool inode_is_open_for_write(const struct inode *inode) return atomic_read(&inode->i_writecount) > 0; } -#ifdef CONFIG_IMA +#if defined(CONFIG_IMA) || defined(CONFIG_FILE_LOCKING) static inline void i_readcount_dec(struct inode *inode) { BUG_ON(!atomic_read(&inode->i_readcount)); diff --git a/include/trace/events/filelock.h b/include/trace/events/filelock.h index fad7befa612d..4b735923f2ff 100644 --- a/include/trace/events/filelock.h +++ b/include/trace/events/filelock.h @@ -203,6 +203,41 @@ TRACE_EVENT(generic_add_lease, show_fl_type(__entry->fl_type)) ); +TRACE_EVENT(leases_conflict, + TP_PROTO(bool conflict, struct file_lock *lease, struct file_lock *breaker), + + TP_ARGS(conflict, lease, breaker), + + TP_STRUCT__entry( + __field(void *, lease) + __field(void *, breaker) + __field(unsigned int, l_fl_flags) + __field(unsigned int, b_fl_flags) + __field(unsigned char, l_fl_type) + __field(unsigned char, b_fl_type) + __field(bool, conflict) + ), + + TP_fast_assign( + __entry->lease = lease; + __entry->l_fl_flags = lease->fl_flags; + __entry->l_fl_type = lease->fl_type; + __entry->breaker = breaker; + __entry->b_fl_flags = breaker->fl_flags; + __entry->b_fl_type = breaker->fl_type; + __entry->conflict = conflict; + ), + + TP_printk("conflict %d: lease=0x%p fl_flags=%s fl_type=%s; breaker=0x%p fl_flags=%s fl_type=%s", + __entry->conflict, + __entry->lease, + show_fl_flags(__entry->l_fl_flags), + show_fl_type(__entry->l_fl_type), + __entry->breaker, + show_fl_flags(__entry->b_fl_flags), + show_fl_type(__entry->b_fl_type)) +); + #endif /* _TRACE_FILELOCK_H */ /* This part must be outside protection */ |