diff options
author | Jens Axboe <axboe@kernel.dk> | 2021-01-19 15:41:52 -0700 |
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committer | Jens Axboe <axboe@kernel.dk> | 2021-02-01 10:02:42 -0700 |
commit | 53dec2ea74f2ef360e8455439be96a780baa6097 (patch) | |
tree | 1310979e2c4fa2b604ed81061fbee004ef1d9e7a /fs/file.c | |
parent | e342c807f556dbcee1370ab78af1d8faf497d771 (diff) |
fs: provide locked helper variant of close_fd_get_file()
Assumes current->files->file_lock is already held on invocation. Helps
the caller check the file before removing the fd, if it needs to.
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'fs/file.c')
-rw-r--r-- | fs/file.c | 36 |
1 files changed, 25 insertions, 11 deletions
diff --git a/fs/file.c b/fs/file.c index dab120b71e44..f3a4bac2cbe9 100644 --- a/fs/file.c +++ b/fs/file.c @@ -22,6 +22,8 @@ #include <linux/close_range.h> #include <net/sock.h> +#include "internal.h" + unsigned int sysctl_nr_open __read_mostly = 1024*1024; unsigned int sysctl_nr_open_min = BITS_PER_LONG; /* our min() is unusable in constant expressions ;-/ */ @@ -732,36 +734,48 @@ int __close_range(unsigned fd, unsigned max_fd, unsigned int flags) } /* - * variant of close_fd that gets a ref on the file for later fput. - * The caller must ensure that filp_close() called on the file, and then - * an fput(). + * See close_fd_get_file() below, this variant assumes current->files->file_lock + * is held. */ -int close_fd_get_file(unsigned int fd, struct file **res) +int __close_fd_get_file(unsigned int fd, struct file **res) { struct files_struct *files = current->files; struct file *file; struct fdtable *fdt; - spin_lock(&files->file_lock); fdt = files_fdtable(files); if (fd >= fdt->max_fds) - goto out_unlock; + goto out_err; file = fdt->fd[fd]; if (!file) - goto out_unlock; + goto out_err; rcu_assign_pointer(fdt->fd[fd], NULL); __put_unused_fd(files, fd); - spin_unlock(&files->file_lock); get_file(file); *res = file; return 0; - -out_unlock: - spin_unlock(&files->file_lock); +out_err: *res = NULL; return -ENOENT; } +/* + * variant of close_fd that gets a ref on the file for later fput. + * The caller must ensure that filp_close() called on the file, and then + * an fput(). + */ +int close_fd_get_file(unsigned int fd, struct file **res) +{ + struct files_struct *files = current->files; + int ret; + + spin_lock(&files->file_lock); + ret = __close_fd_get_file(fd, res); + spin_unlock(&files->file_lock); + + return ret; +} + void do_close_on_exec(struct files_struct *files) { unsigned i; |