From 4e1e018ecc6f7bfd10fc75b3ff9715cc8164e0a2 Mon Sep 17 00:00:00 2001 From: Al Viro Date: Sat, 26 Jul 2008 16:01:20 -0400 Subject: [PATCH] fix RLIM_NOFILE handling * dup2() should return -EBADF on exceeded sysctl_nr_open * dup() should *not* return -EINVAL even if you have rlimit set to 0; it should get -EMFILE instead. Check for orig_start exceeding rlimit taken to sys_fcntl(). Failing expand_files() in dup{2,3}() now gets -EMFILE remapped to -EBADF. Consequently, remaining checks for rlimit are taken to expand_files(). Signed-off-by: Al Viro --- fs/file.c | 9 +++++++++ 1 file changed, 9 insertions(+) (limited to 'fs/file.c') diff --git a/fs/file.c b/fs/file.c index 7b3887e054d0..d8773b19fe47 100644 --- a/fs/file.c +++ b/fs/file.c @@ -250,9 +250,18 @@ int expand_files(struct files_struct *files, int nr) struct fdtable *fdt; fdt = files_fdtable(files); + + /* + * N.B. For clone tasks sharing a files structure, this test + * will limit the total number of files that can be opened. + */ + if (nr >= current->signal->rlim[RLIMIT_NOFILE].rlim_cur) + return -EMFILE; + /* Do we need to expand? */ if (nr < fdt->max_fds) return 0; + /* Can we expand? */ if (nr >= sysctl_nr_open) return -EMFILE; -- cgit v1.2.3 From 1027abe8827b47f7e9c4ed6514fde3d44f79963c Mon Sep 17 00:00:00 2001 From: Al Viro Date: Wed, 30 Jul 2008 04:13:04 -0400 Subject: [PATCH] merge locate_fd() and get_unused_fd() New primitive: alloc_fd(start, flags). get_unused_fd() and get_unused_fd_flags() become wrappers on top of it. Signed-off-by: Al Viro --- fs/file.c | 61 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 61 insertions(+) (limited to 'fs/file.c') diff --git a/fs/file.c b/fs/file.c index d8773b19fe47..f313314f996f 100644 --- a/fs/file.c +++ b/fs/file.c @@ -6,6 +6,7 @@ * Manage the dynamic fd arrays in the process files_struct. */ +#include #include #include #include @@ -432,3 +433,63 @@ struct files_struct init_files = { }, .file_lock = __SPIN_LOCK_UNLOCKED(init_task.file_lock), }; + +/* + * allocate a file descriptor, mark it busy. + */ +int alloc_fd(unsigned start, unsigned flags) +{ + struct files_struct *files = current->files; + unsigned int fd; + int error; + struct fdtable *fdt; + + spin_lock(&files->file_lock); +repeat: + fdt = files_fdtable(files); + fd = start; + if (fd < files->next_fd) + fd = files->next_fd; + + if (fd < fdt->max_fds) + fd = find_next_zero_bit(fdt->open_fds->fds_bits, + fdt->max_fds, fd); + + error = expand_files(files, fd); + if (error < 0) + goto out; + + /* + * If we needed to expand the fs array we + * might have blocked - try again. + */ + if (error) + goto repeat; + + if (start <= files->next_fd) + files->next_fd = fd + 1; + + FD_SET(fd, fdt->open_fds); + if (flags & O_CLOEXEC) + FD_SET(fd, fdt->close_on_exec); + else + FD_CLR(fd, fdt->close_on_exec); + error = fd; +#if 1 + /* Sanity check */ + if (rcu_dereference(fdt->fd[fd]) != NULL) { + printk(KERN_WARNING "alloc_fd: slot %d not NULL!\n", fd); + rcu_assign_pointer(fdt->fd[fd], NULL); + } +#endif + +out: + spin_unlock(&files->file_lock); + return error; +} + +int get_unused_fd(void) +{ + return alloc_fd(0, 0); +} +EXPORT_SYMBOL(get_unused_fd); -- cgit v1.2.3