Mercurial > hg > nginx
view src/os/unix/ngx_files.c @ 6422:768e287a6f36
Fixed sendfile in threads (or with aio preload) and subrequests.
If sendfile in threads is used, it is possible that multiple
subrequests will trigger multiple ngx_linux_sendfile_thread() calls,
as operations are only serialized in output chain based on r->aio,
that is, on subrequest level.
This resulted in "task #N already active" alerts, in particular, when
running proxy_store.t with "aio threads; sendfile on;".
Fix is to tolerate duplicate calls, with an additional safety check
that the file is the same as previously used.
The same problem also affects "aio on; sendfile on;" on FreeBSD
(previously known as "aio sendfile;"), where aio->preload_handler()
could be called multiple times due to similar reasons, resulting in
"second aio post" alerts. Fix is the same as well.
It is also believed that similar problems can arise if a filter
calls the next body filter multiple times for some reason. These are
mostly theoretical though.
author | Maxim Dounin <mdounin@mdounin.ru> |
---|---|
date | Thu, 03 Mar 2016 21:14:12 +0300 |
parents | 3832b608dc8d |
children | 9fd738b85fad |
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/* * Copyright (C) Igor Sysoev * Copyright (C) Nginx, Inc. */ #include <ngx_config.h> #include <ngx_core.h> #if (NGX_THREADS) #include <ngx_thread_pool.h> static void ngx_thread_read_handler(void *data, ngx_log_t *log); #endif static ngx_chain_t *ngx_chain_to_iovec(ngx_iovec_t *vec, ngx_chain_t *cl); static ssize_t ngx_writev_file(ngx_file_t *file, ngx_iovec_t *vec, off_t offset); #if (NGX_HAVE_FILE_AIO) ngx_uint_t ngx_file_aio = 1; #endif ssize_t ngx_read_file(ngx_file_t *file, u_char *buf, size_t size, off_t offset) { ssize_t n; ngx_log_debug4(NGX_LOG_DEBUG_CORE, file->log, 0, "read: %d, %p, %uz, %O", file->fd, buf, size, offset); #if (NGX_HAVE_PREAD) n = pread(file->fd, buf, size, offset); if (n == -1) { ngx_log_error(NGX_LOG_CRIT, file->log, ngx_errno, "pread() \"%s\" failed", file->name.data); return NGX_ERROR; } #else if (file->sys_offset != offset) { if (lseek(file->fd, offset, SEEK_SET) == -1) { ngx_log_error(NGX_LOG_CRIT, file->log, ngx_errno, "lseek() \"%s\" failed", file->name.data); return NGX_ERROR; } file->sys_offset = offset; } n = read(file->fd, buf, size); if (n == -1) { ngx_log_error(NGX_LOG_CRIT, file->log, ngx_errno, "read() \"%s\" failed", file->name.data); return NGX_ERROR; } file->sys_offset += n; #endif file->offset += n; return n; } #if (NGX_THREADS) typedef struct { ngx_fd_t fd; u_char *buf; size_t size; off_t offset; size_t read; ngx_err_t err; } ngx_thread_read_ctx_t; ssize_t ngx_thread_read(ngx_thread_task_t **taskp, ngx_file_t *file, u_char *buf, size_t size, off_t offset, ngx_pool_t *pool) { ngx_thread_task_t *task; ngx_thread_read_ctx_t *ctx; ngx_log_debug4(NGX_LOG_DEBUG_CORE, file->log, 0, "thread read: %d, %p, %uz, %O", file->fd, buf, size, offset); task = *taskp; if (task == NULL) { task = ngx_thread_task_alloc(pool, sizeof(ngx_thread_read_ctx_t)); if (task == NULL) { return NGX_ERROR; } task->handler = ngx_thread_read_handler; *taskp = task; } ctx = task->ctx; if (task->event.complete) { task->event.complete = 0; if (ctx->err) { ngx_log_error(NGX_LOG_CRIT, file->log, ctx->err, "pread() \"%s\" failed", file->name.data); return NGX_ERROR; } return ctx->read; } ctx->fd = file->fd; ctx->buf = buf; ctx->size = size; ctx->offset = offset; if (file->thread_handler(task, file) != NGX_OK) { return NGX_ERROR; } return NGX_AGAIN; } #if (NGX_HAVE_PREAD) static void ngx_thread_read_handler(void *data, ngx_log_t *log) { ngx_thread_read_ctx_t *ctx = data; ssize_t n; ngx_log_debug0(NGX_LOG_DEBUG_CORE, log, 0, "thread read handler"); n = pread(ctx->fd, ctx->buf, ctx->size, ctx->offset); if (n == -1) { ctx->err = ngx_errno; } else { ctx->read = n; ctx->err = 0; } #if 0 ngx_time_update(); #endif ngx_log_debug4(NGX_LOG_DEBUG_CORE, log, 0, "pread: %z (err: %i) of %uz @%O", n, ctx->err, ctx->size, ctx->offset); } #else #error pread() is required! #endif #endif /* NGX_THREADS */ ssize_t ngx_write_file(ngx_file_t *file, u_char *buf, size_t size, off_t offset) { ssize_t n, written; ngx_err_t err; ngx_log_debug4(NGX_LOG_DEBUG_CORE, file->log, 0, "write: %d, %p, %uz, %O", file->fd, buf, size, offset); written = 0; #if (NGX_HAVE_PWRITE) for ( ;; ) { n = pwrite(file->fd, buf + written, size, offset); if (n == -1) { err = ngx_errno; if (err == NGX_EINTR) { ngx_log_debug0(NGX_LOG_DEBUG_CORE, file->log, err, "pwrite() was interrupted"); continue; } ngx_log_error(NGX_LOG_CRIT, file->log, err, "pwrite() \"%s\" failed", file->name.data); return NGX_ERROR; } file->offset += n; written += n; if ((size_t) n == size) { return written; } offset += n; size -= n; } #else if (file->sys_offset != offset) { if (lseek(file->fd, offset, SEEK_SET) == -1) { ngx_log_error(NGX_LOG_CRIT, file->log, ngx_errno, "lseek() \"%s\" failed", file->name.data); return NGX_ERROR; } file->sys_offset = offset; } for ( ;; ) { n = write(file->fd, buf + written, size); if (n == -1) { err = ngx_errno; if (err == NGX_EINTR) { ngx_log_debug0(NGX_LOG_DEBUG_CORE, file->log, err, "write() was interrupted"); continue; } ngx_log_error(NGX_LOG_CRIT, file->log, err, "write() \"%s\" failed", file->name.data); return NGX_ERROR; } file->sys_offset += n; file->offset += n; written += n; if ((size_t) n == size) { return written; } size -= n; } #endif } ngx_fd_t ngx_open_tempfile(u_char *name, ngx_uint_t persistent, ngx_uint_t access) { ngx_fd_t fd; fd = open((const char *) name, O_CREAT|O_EXCL|O_RDWR, access ? access : 0600); if (fd != -1 && !persistent) { (void) unlink((const char *) name); } return fd; } ssize_t ngx_write_chain_to_file(ngx_file_t *file, ngx_chain_t *cl, off_t offset, ngx_pool_t *pool) { ssize_t total, n; ngx_iovec_t vec; struct iovec iovs[NGX_IOVS_PREALLOCATE]; /* use pwrite() if there is the only buf in a chain */ if (cl->next == NULL) { return ngx_write_file(file, cl->buf->pos, (size_t) (cl->buf->last - cl->buf->pos), offset); } total = 0; vec.iovs = iovs; vec.nalloc = NGX_IOVS_PREALLOCATE; do { /* create the iovec and coalesce the neighbouring bufs */ cl = ngx_chain_to_iovec(&vec, cl); /* use pwrite() if there is the only iovec buffer */ if (vec.count == 1) { n = ngx_write_file(file, (u_char *) iovs[0].iov_base, iovs[0].iov_len, offset); if (n == NGX_ERROR) { return n; } return total + n; } n = ngx_writev_file(file, &vec, offset); if (n == NGX_ERROR) { return n; } offset += n; total += n; } while (cl); return total; } static ngx_chain_t * ngx_chain_to_iovec(ngx_iovec_t *vec, ngx_chain_t *cl) { size_t total, size; u_char *prev; ngx_uint_t n; struct iovec *iov; iov = NULL; prev = NULL; total = 0; n = 0; for ( /* void */ ; cl; cl = cl->next) { size = cl->buf->last - cl->buf->pos; if (prev == cl->buf->pos) { iov->iov_len += size; } else { if (n == vec->nalloc) { break; } iov = &vec->iovs[n++]; iov->iov_base = (void *) cl->buf->pos; iov->iov_len = size; } prev = cl->buf->pos + size; total += size; } vec->count = n; vec->size = total; return cl; } static ssize_t ngx_writev_file(ngx_file_t *file, ngx_iovec_t *vec, off_t offset) { ssize_t n; ngx_err_t err; ngx_log_debug3(NGX_LOG_DEBUG_CORE, file->log, 0, "writev: %d, %uz, %O", file->fd, vec->size, offset); #if (NGX_HAVE_PWRITEV) eintr: n = pwritev(file->fd, vec->iovs, vec->count, offset); if (n == -1) { err = ngx_errno; if (err == NGX_EINTR) { ngx_log_debug0(NGX_LOG_DEBUG_CORE, file->log, err, "pwritev() was interrupted"); goto eintr; } ngx_log_error(NGX_LOG_CRIT, file->log, err, "pwritev() \"%s\" failed", file->name.data); return NGX_ERROR; } if ((size_t) n != vec->size) { ngx_log_error(NGX_LOG_CRIT, file->log, 0, "pwritev() \"%s\" has written only %z of %uz", file->name.data, n, vec->size); return NGX_ERROR; } #else if (file->sys_offset != offset) { if (lseek(file->fd, offset, SEEK_SET) == -1) { ngx_log_error(NGX_LOG_CRIT, file->log, ngx_errno, "lseek() \"%s\" failed", file->name.data); return NGX_ERROR; } file->sys_offset = offset; } eintr: n = writev(file->fd, vec->iovs, vec->count); if (n == -1) { err = ngx_errno; if (err == NGX_EINTR) { ngx_log_debug0(NGX_LOG_DEBUG_CORE, file->log, err, "writev() was interrupted"); goto eintr; } ngx_log_error(NGX_LOG_CRIT, file->log, err, "writev() \"%s\" failed", file->name.data); return NGX_ERROR; } if ((size_t) n != vec->size) { ngx_log_error(NGX_LOG_CRIT, file->log, 0, "writev() \"%s\" has written only %z of %uz", file->name.data, n, vec->size); return NGX_ERROR; } file->sys_offset += n; #endif file->offset += n; return n; } ngx_int_t ngx_set_file_time(u_char *name, ngx_fd_t fd, time_t s) { struct timeval tv[2]; tv[0].tv_sec = ngx_time(); tv[0].tv_usec = 0; tv[1].tv_sec = s; tv[1].tv_usec = 0; if (utimes((char *) name, tv) != -1) { return NGX_OK; } return NGX_ERROR; } ngx_int_t ngx_create_file_mapping(ngx_file_mapping_t *fm) { fm->fd = ngx_open_file(fm->name, NGX_FILE_RDWR, NGX_FILE_TRUNCATE, NGX_FILE_DEFAULT_ACCESS); if (fm->fd == NGX_INVALID_FILE) { ngx_log_error(NGX_LOG_CRIT, fm->log, ngx_errno, ngx_open_file_n " \"%s\" failed", fm->name); return NGX_ERROR; } if (ftruncate(fm->fd, fm->size) == -1) { ngx_log_error(NGX_LOG_CRIT, fm->log, ngx_errno, "ftruncate() \"%s\" failed", fm->name); goto failed; } fm->addr = mmap(NULL, fm->size, PROT_READ|PROT_WRITE, MAP_SHARED, fm->fd, 0); if (fm->addr != MAP_FAILED) { return NGX_OK; } ngx_log_error(NGX_LOG_CRIT, fm->log, ngx_errno, "mmap(%uz) \"%s\" failed", fm->size, fm->name); failed: if (ngx_close_file(fm->fd) == NGX_FILE_ERROR) { ngx_log_error(NGX_LOG_ALERT, fm->log, ngx_errno, ngx_close_file_n " \"%s\" failed", fm->name); } return NGX_ERROR; } void ngx_close_file_mapping(ngx_file_mapping_t *fm) { if (munmap(fm->addr, fm->size) == -1) { ngx_log_error(NGX_LOG_CRIT, fm->log, ngx_errno, "munmap(%uz) \"%s\" failed", fm->size, fm->name); } if (ngx_close_file(fm->fd) == NGX_FILE_ERROR) { ngx_log_error(NGX_LOG_ALERT, fm->log, ngx_errno, ngx_close_file_n " \"%s\" failed", fm->name); } } ngx_int_t ngx_open_dir(ngx_str_t *name, ngx_dir_t *dir) { dir->dir = opendir((const char *) name->data); if (dir->dir == NULL) { return NGX_ERROR; } dir->valid_info = 0; return NGX_OK; } ngx_int_t ngx_read_dir(ngx_dir_t *dir) { dir->de = readdir(dir->dir); if (dir->de) { #if (NGX_HAVE_D_TYPE) dir->type = dir->de->d_type; #else dir->type = 0; #endif return NGX_OK; } return NGX_ERROR; } ngx_int_t ngx_open_glob(ngx_glob_t *gl) { int n; n = glob((char *) gl->pattern, 0, NULL, &gl->pglob); if (n == 0) { return NGX_OK; } #ifdef GLOB_NOMATCH if (n == GLOB_NOMATCH && gl->test) { return NGX_OK; } #endif return NGX_ERROR; } ngx_int_t ngx_read_glob(ngx_glob_t *gl, ngx_str_t *name) { size_t count; #ifdef GLOB_NOMATCH count = (size_t) gl->pglob.gl_pathc; #else count = (size_t) gl->pglob.gl_matchc; #endif if (gl->n < count) { name->len = (size_t) ngx_strlen(gl->pglob.gl_pathv[gl->n]); name->data = (u_char *) gl->pglob.gl_pathv[gl->n]; gl->n++; return NGX_OK; } return NGX_DONE; } void ngx_close_glob(ngx_glob_t *gl) { globfree(&gl->pglob); } ngx_err_t ngx_trylock_fd(ngx_fd_t fd) { struct flock fl; ngx_memzero(&fl, sizeof(struct flock)); fl.l_type = F_WRLCK; fl.l_whence = SEEK_SET; if (fcntl(fd, F_SETLK, &fl) == -1) { return ngx_errno; } return 0; } ngx_err_t ngx_lock_fd(ngx_fd_t fd) { struct flock fl; ngx_memzero(&fl, sizeof(struct flock)); fl.l_type = F_WRLCK; fl.l_whence = SEEK_SET; if (fcntl(fd, F_SETLKW, &fl) == -1) { return ngx_errno; } return 0; } ngx_err_t ngx_unlock_fd(ngx_fd_t fd) { struct flock fl; ngx_memzero(&fl, sizeof(struct flock)); fl.l_type = F_UNLCK; fl.l_whence = SEEK_SET; if (fcntl(fd, F_SETLK, &fl) == -1) { return ngx_errno; } return 0; } #if (NGX_HAVE_POSIX_FADVISE) && !(NGX_HAVE_F_READAHEAD) ngx_int_t ngx_read_ahead(ngx_fd_t fd, size_t n) { int err; err = posix_fadvise(fd, 0, 0, POSIX_FADV_SEQUENTIAL); if (err == 0) { return 0; } ngx_set_errno(err); return NGX_FILE_ERROR; } #endif #if (NGX_HAVE_O_DIRECT) ngx_int_t ngx_directio_on(ngx_fd_t fd) { int flags; flags = fcntl(fd, F_GETFL); if (flags == -1) { return NGX_FILE_ERROR; } return fcntl(fd, F_SETFL, flags | O_DIRECT); } ngx_int_t ngx_directio_off(ngx_fd_t fd) { int flags; flags = fcntl(fd, F_GETFL); if (flags == -1) { return NGX_FILE_ERROR; } return fcntl(fd, F_SETFL, flags & ~O_DIRECT); } #endif #if (NGX_HAVE_STATFS) size_t ngx_fs_bsize(u_char *name) { struct statfs fs; if (statfs((char *) name, &fs) == -1) { return 512; } if ((fs.f_bsize % 512) != 0) { return 512; } return (size_t) fs.f_bsize; } #elif (NGX_HAVE_STATVFS) size_t ngx_fs_bsize(u_char *name) { struct statvfs fs; if (statvfs((char *) name, &fs) == -1) { return 512; } if ((fs.f_frsize % 512) != 0) { return 512; } return (size_t) fs.f_frsize; } #else size_t ngx_fs_bsize(u_char *name) { return 512; } #endif