/erts/emulator/drivers/unix/unix_efile.c
C | 1057 lines | 763 code | 116 blank | 178 comment | 240 complexity | 1d1f8c3caf2deb1045a03454ce727725 MD5 | raw file
Possible License(s): BSD-3-Clause, LGPL-2.1, MPL-2.0-no-copyleft-exception, Apache-2.0
- /*
- * %CopyrightBegin%
- *
- * Copyright Ericsson AB 1997-2012. All Rights Reserved.
- *
- * The contents of this file are subject to the Erlang Public License,
- * Version 1.1, (the "License"); you may not use this file except in
- * compliance with the License. You should have received a copy of the
- * Erlang Public License along with this software. If not, it can be
- * retrieved online at http://www.erlang.org/.
- *
- * Software distributed under the License is distributed on an "AS IS"
- * basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
- * the License for the specific language governing rights and limitations
- * under the License.
- *
- * %CopyrightEnd%
- */
- /*
- * Purpose: Provides file and directory operations for Unix.
- */
- #ifdef HAVE_CONFIG_H
- # include "config.h"
- #endif
- #if defined(HAVE_POSIX_FALLOCATE) && !defined(__sun) && !defined(__sun__)
- #define _XOPEN_SOURCE 600
- #endif
- #if !defined(_GNU_SOURCE) && defined(HAVE_LINUX_FALLOC_H)
- #define _GNU_SOURCE
- #endif
- #include "sys.h"
- #include "erl_driver.h"
- #include "erl_efile.h"
- #include <utime.h>
- #ifdef HAVE_UNISTD_H
- #include <unistd.h>
- #endif
- #ifdef HAVE_SYS_UIO_H
- #include <sys/types.h>
- #include <sys/uio.h>
- #endif
- #if defined(HAVE_SENDFILE) && (defined(__linux__) || (defined(__sun) && defined(__SVR4)))
- #include <sys/sendfile.h>
- #endif
- #if defined(__APPLE__) && defined(__MACH__) && !defined(__DARWIN__)
- #define DARWIN 1
- #endif
- #if defined(DARWIN) || defined(HAVE_LINUX_FALLOC_H) || defined(HAVE_POSIX_FALLOCATE)
- #include <fcntl.h>
- #endif
- #ifdef HAVE_LINUX_FALLOC_H
- #include <linux/falloc.h>
- #endif
- #ifdef SUNOS4
- # define getcwd(buf, size) getwd(buf)
- #endif
- /* Find a definition of MAXIOV, that is used in the code later. */
- #if defined IOV_MAX
- #define MAXIOV IOV_MAX
- #elif defined UIO_MAXIOV
- #define MAXIOV UIO_MAXIOV
- #else
- #define MAXIOV 16
- #endif
- /*
- * Macros for testing file types.
- */
- #define ISDIR(st) (((st).st_mode & S_IFMT) == S_IFDIR)
- #define ISREG(st) (((st).st_mode & S_IFMT) == S_IFREG)
- #define ISDEV(st) \
- (((st).st_mode&S_IFMT) == S_IFCHR || ((st).st_mode&S_IFMT) == S_IFBLK)
- #define ISLNK(st) (((st).st_mode & S_IFLNK) == S_IFLNK)
- #ifdef NO_UMASK
- #define FILE_MODE 0644
- #define DIR_MODE 0755
- #else
- #define FILE_MODE 0666
- #define DIR_MODE 0777
- #endif
- #define IS_DOT_OR_DOTDOT(s) \
- (s[0] == '.' && (s[1] == '\0' || (s[1] == '.' && s[2] == '\0')))
- static int check_error(int result, Efile_error* errInfo);
- static int
- check_error(int result, Efile_error *errInfo)
- {
- if (result < 0) {
- errInfo->posix_errno = errInfo->os_errno = errno;
- return 0;
- }
- return 1;
- }
- int
- efile_mkdir(Efile_error* errInfo, /* Where to return error codes. */
- char* name) /* Name of directory to create. */
- {
- #ifdef NO_MKDIR_MODE
- return check_error(mkdir(name), errInfo);
- #else
- return check_error(mkdir(name, DIR_MODE), errInfo);
- #endif
- }
- int
- efile_rmdir(Efile_error* errInfo, /* Where to return error codes. */
- char* name) /* Name of directory to delete. */
- {
- if (rmdir(name) == 0) {
- return 1;
- }
- if (errno == ENOTEMPTY) {
- errno = EEXIST;
- }
- if (errno == EEXIST) {
- int saved_errno = errno;
- struct stat file_stat;
- struct stat cwd_stat;
- /*
- * The error code might be wrong if this is the current directory.
- */
- if (stat(name, &file_stat) == 0 && stat(".", &cwd_stat) == 0 &&
- file_stat.st_ino == cwd_stat.st_ino &&
- file_stat.st_dev == cwd_stat.st_dev) {
- saved_errno = EINVAL;
- }
- errno = saved_errno;
- }
- return check_error(-1, errInfo);
- }
- int
- efile_delete_file(Efile_error* errInfo, /* Where to return error codes. */
- char* name) /* Name of file to delete. */
- {
- if (unlink(name) == 0) {
- return 1;
- }
- if (errno == EISDIR) { /* Linux sets the wrong error code. */
- errno = EPERM;
- }
- return check_error(-1, errInfo);
- }
- /*
- *---------------------------------------------------------------------------
- *
- * Changes the name of an existing file or directory, from src to dst.
- * If src and dst refer to the same file or directory, does nothing
- * and returns success. Otherwise if dst already exists, it will be
- * deleted and replaced by src subject to the following conditions:
- * If src is a directory, dst may be an empty directory.
- * If src is a file, dst may be a file.
- * In any other situation where dst already exists, the rename will
- * fail.
- *
- * Results:
- * If the directory was successfully created, returns 1.
- * Otherwise the return value is 0 and errno is set to
- * indicate the error. Some possible values for errno are:
- *
- * EACCES: src or dst parent directory can't be read and/or written.
- * EEXIST: dst is a non-empty directory.
- * EINVAL: src is a root directory or dst is a subdirectory of src.
- * EISDIR: dst is a directory, but src is not.
- * ENOENT: src doesn't exist, or src or dst is "".
- * ENOTDIR: src is a directory, but dst is not.
- * EXDEV: src and dst are on different filesystems.
- *
- * Side effects:
- * The implementation of rename may allow cross-filesystem renames,
- * but the caller should be prepared to emulate it with copy and
- * delete if errno is EXDEV.
- *
- *---------------------------------------------------------------------------
- */
- int
- efile_rename(Efile_error* errInfo, /* Where to return error codes. */
- char* src, /* Original name. */
- char* dst) /* New name. */
- {
- if (rename(src, dst) == 0) {
- return 1;
- }
- if (errno == ENOTEMPTY) {
- errno = EEXIST;
- }
- #if defined (sparc)
- /*
- * SunOS 4.1.4 reports overwriting a non-empty directory with a
- * directory as EINVAL instead of EEXIST (first rule out the correct
- * EINVAL result code for moving a directory into itself). Must be
- * conditionally compiled because realpath() is only defined on SunOS.
- */
- if (errno == EINVAL) {
- char srcPath[MAXPATHLEN], dstPath[MAXPATHLEN];
- DIR *dirPtr;
- struct dirent *dirEntPtr;
- #ifdef PURIFY
- memset(srcPath, '\0', sizeof(srcPath));
- memset(dstPath, '\0', sizeof(dstPath));
- #endif
- if ((realpath(src, srcPath) != NULL)
- && (realpath(dst, dstPath) != NULL)
- && (strncmp(srcPath, dstPath, strlen(srcPath)) != 0)) {
- dirPtr = opendir(dst);
- if (dirPtr != NULL) {
- while ((dirEntPtr = readdir(dirPtr)) != NULL) {
- if ((strcmp(dirEntPtr->d_name, ".") != 0) &&
- (strcmp(dirEntPtr->d_name, "..") != 0)) {
- errno = EEXIST;
- closedir(dirPtr);
- return check_error(-1, errInfo);
- }
- }
- closedir(dirPtr);
- }
- }
- errno = EINVAL;
- }
- #endif /* sparc */
- if (strcmp(src, "/") == 0) {
- /*
- * Alpha reports renaming / as EBUSY and Linux reports it as EACCES,
- * instead of EINVAL.
- */
-
- errno = EINVAL;
- }
- /*
- * DEC Alpha OSF1 V3.0 returns EACCES when attempting to move a
- * file across filesystems and the parent directory of that file is
- * not writable. Most other systems return EXDEV. Does nothing to
- * correct this behavior.
- */
- return check_error(-1, errInfo);
- }
- int
- efile_chdir(Efile_error* errInfo, /* Where to return error codes. */
- char* name) /* Name of directory to make current. */
- {
- return check_error(chdir(name), errInfo);
- }
- int
- efile_getdcwd(Efile_error* errInfo, /* Where to return error codes. */
- int drive, /* 0 - current, 1 - A, 2 - B etc. */
- char* buffer, /* Where to return the current
- directory. */
- size_t size) /* Size of buffer. */
- {
- if (drive == 0) {
- if (getcwd(buffer, size) == NULL)
- return check_error(-1, errInfo);
-
- #ifdef SIMSPARCSOLARIS
- /* We get "host:" prepended to the dirname - remove!. */
- {
- int i = 0;
- int j = 0;
- while ((buffer[i] != ':') && (buffer[i] != '\0')) i++;
- if (buffer[i] == ':') {
- i++;
- while ((buffer[j++] = buffer[i++]) != '\0');
- }
- }
- #endif
- return 1;
- }
- /*
- * Drives other than 0 is not supported on Unix.
- */
- errno = ENOTSUP;
- return check_error(-1, errInfo);
- }
- int
- efile_readdir(Efile_error* errInfo, /* Where to return error codes. */
- char* name, /* Name of directory to open. */
- EFILE_DIR_HANDLE* p_dir_handle, /* Pointer to directory
- handle of
- open directory.*/
- char* buffer, /* Pointer to buffer for
- one filename. */
- size_t *size) /* in-out Size of buffer, length
- of name. */
- {
- DIR *dp; /* Pointer to directory structure. */
- struct dirent* dirp; /* Pointer to directory entry. */
- /*
- * If this is the first call, we must open the directory.
- */
- if (*p_dir_handle == NULL) {
- dp = opendir(name);
- if (dp == NULL)
- return check_error(-1, errInfo);
- *p_dir_handle = (EFILE_DIR_HANDLE) dp;
- }
- /*
- * Retrieve the name of the next file using the directory handle.
- */
- dp = *((DIR **)((void *)p_dir_handle));
- for (;;) {
- dirp = readdir(dp);
- if (dirp == NULL) {
- closedir(dp);
- return 0;
- }
- if (IS_DOT_OR_DOTDOT(dirp->d_name))
- continue;
- buffer[0] = '\0';
- strncat(buffer, dirp->d_name, (*size)-1);
- *size = strlen(dirp->d_name);
- return 1;
- }
- }
- int
- efile_openfile(Efile_error* errInfo, /* Where to return error codes. */
- char* name, /* Name of directory to open. */
- int flags, /* Flags to user for opening. */
- int* pfd, /* Where to store the file
- descriptor. */
- Sint64 *pSize) /* Where to store the size of the
- file. */
- {
- struct stat statbuf;
- int fd;
- int mode; /* Open mode. */
- if (stat(name, &statbuf) >= 0 && !ISREG(statbuf)) {
- /*
- * For UNIX only, here is some ugly code to allow
- * /dev/null to be opened as a file.
- *
- * Assumption: The i-node number for /dev/null cannot be zero.
- */
- static ino_t dev_null_ino = 0;
- if (dev_null_ino == 0) {
- struct stat nullstatbuf;
-
- if (stat("/dev/null", &nullstatbuf) >= 0) {
- dev_null_ino = nullstatbuf.st_ino;
- }
- }
- if (!(dev_null_ino && statbuf.st_ino == dev_null_ino)) {
- errno = EISDIR;
- return check_error(-1, errInfo);
- }
- }
- switch (flags & (EFILE_MODE_READ|EFILE_MODE_WRITE)) {
- case EFILE_MODE_READ:
- mode = O_RDONLY;
- break;
- case EFILE_MODE_WRITE:
- if (flags & EFILE_NO_TRUNCATE)
- mode = O_WRONLY | O_CREAT;
- else
- mode = O_WRONLY | O_CREAT | O_TRUNC;
- break;
- case EFILE_MODE_READ_WRITE:
- mode = O_RDWR | O_CREAT;
- break;
- default:
- errno = EINVAL;
- return check_error(-1, errInfo);
- }
- if (flags & EFILE_MODE_APPEND) {
- mode &= ~O_TRUNC;
- mode |= O_APPEND;
- }
- if (flags & EFILE_MODE_EXCL) {
- mode |= O_EXCL;
- }
- fd = open(name, mode, FILE_MODE);
- if (!check_error(fd, errInfo))
- return 0;
- *pfd = fd;
- if (pSize) {
- *pSize = statbuf.st_size;
- }
- return 1;
- }
- int
- efile_may_openfile(Efile_error* errInfo, char *name) {
- struct stat statbuf; /* Information about the file */
- int result;
-
- result = stat(name, &statbuf);
- if (!check_error(result, errInfo))
- return 0;
- if (!ISREG(statbuf)) {
- errno = EISDIR;
- return check_error(-1, errInfo);
- }
- return 1;
- }
- void
- efile_closefile(int fd)
- {
- close(fd);
- }
- int
- efile_fdatasync(Efile_error *errInfo, /* Where to return error codes. */
- int fd) /* File descriptor for file to sync data. */
- {
- #ifdef HAVE_FDATASYNC
- return check_error(fdatasync(fd), errInfo);
- #else
- return efile_fsync(errInfo, fd);
- #endif
- }
- int
- efile_fsync(Efile_error *errInfo, /* Where to return error codes. */
- int fd) /* File descriptor for file to sync. */
- {
- #ifdef NO_FSYNC
- undefined fsync /* XXX: Really? */
- #else
- #if defined(DARWIN) && defined(F_FULLFSYNC)
- return check_error(fcntl(fd, F_FULLFSYNC), errInfo);
- #else
- return check_error(fsync(fd), errInfo);
- #endif /* DARWIN */
- #endif /* NO_FSYNC */
- }
- int
- efile_fileinfo(Efile_error* errInfo, Efile_info* pInfo,
- char* name, int info_for_link)
- {
- struct stat statbuf; /* Information about the file */
- int result;
- if (info_for_link) {
- result = lstat(name, &statbuf);
- } else {
- result = stat(name, &statbuf);
- }
- if (!check_error(result, errInfo)) {
- return 0;
- }
- #if SIZEOF_OFF_T == 4
- pInfo->size_high = 0;
- #else
- pInfo->size_high = (Uint32)(statbuf.st_size >> 32);
- #endif
- pInfo->size_low = (Uint32)statbuf.st_size;
- #ifdef NO_ACCESS
- /* Just look at read/write access for owner. */
- pInfo->access = ((statbuf.st_mode >> 6) & 07) >> 1;
- #else
- pInfo->access = FA_NONE;
- if (access(name, R_OK) == 0)
- pInfo->access |= FA_READ;
- if (access(name, W_OK) == 0)
- pInfo->access |= FA_WRITE;
- #endif
- if (ISDEV(statbuf))
- pInfo->type = FT_DEVICE;
- else if (ISDIR(statbuf))
- pInfo->type = FT_DIRECTORY;
- else if (ISREG(statbuf))
- pInfo->type = FT_REGULAR;
- else if (ISLNK(statbuf))
- pInfo->type = FT_SYMLINK;
- else
- pInfo->type = FT_OTHER;
- pInfo->accessTime = statbuf.st_atime;
- pInfo->modifyTime = statbuf.st_mtime;
- pInfo->cTime = statbuf.st_ctime;
- pInfo->mode = statbuf.st_mode;
- pInfo->links = statbuf.st_nlink;
- pInfo->major_device = statbuf.st_dev;
- pInfo->minor_device = statbuf.st_rdev;
- pInfo->inode = statbuf.st_ino;
- pInfo->uid = statbuf.st_uid;
- pInfo->gid = statbuf.st_gid;
- return 1;
- }
- int
- efile_write_info(Efile_error *errInfo, Efile_info *pInfo, char *name)
- {
- struct utimbuf tval;
- /*
- * On some systems chown will always fail for a non-root user unless
- * POSIX_CHOWN_RESTRICTED is not set. Others will succeed as long as
- * you don't try to chown a file to someone besides youself.
- */
- if (chown(name, pInfo->uid, pInfo->gid) && errno != EPERM) {
- return check_error(-1, errInfo);
- }
- if (pInfo->mode != -1) {
- mode_t newMode = pInfo->mode & (S_ISUID | S_ISGID |
- S_IRWXU | S_IRWXG | S_IRWXO);
- if (chmod(name, newMode)) {
- newMode &= ~(S_ISUID | S_ISGID);
- if (chmod(name, newMode)) {
- return check_error(-1, errInfo);
- }
- }
- }
- tval.actime = pInfo->accessTime;
- tval.modtime = pInfo->modifyTime;
- return check_error(utime(name, &tval), errInfo);
- }
- int
- efile_write(Efile_error* errInfo, /* Where to return error codes. */
- int flags, /* Flags given when file was
- opened. */
- int fd, /* File descriptor to write to. */
- char* buf, /* Buffer to write. */
- size_t count) /* Number of bytes to write. */
- {
- ssize_t written; /* Bytes written in last operation. */
- while (count > 0) {
- if ((written = write(fd, buf, count)) < 0) {
- if (errno != EINTR)
- return check_error(-1, errInfo);
- else
- written = 0;
- }
- ASSERT(written <= count);
- buf += written;
- count -= written;
- }
- return 1;
- }
- int
- efile_writev(Efile_error* errInfo, /* Where to return error codes */
- int flags, /* Flags given when file was
- * opened */
- int fd, /* File descriptor to write to */
- SysIOVec* iov, /* Vector of buffer structs.
- * The structs may be changed i.e.
- * due to incomplete writes */
- int iovcnt) /* Number of structs in vector */
- {
- int cnt = 0; /* Buffers so far written */
- ASSERT(iovcnt >= 0);
-
- while (cnt < iovcnt) {
- if ((! iov[cnt].iov_base) || (iov[cnt].iov_len <= 0)) {
- /* Empty buffer - skip */
- cnt++;
- } else { /* Non-empty buffer */
- ssize_t w; /* Bytes written in this call */
- #ifdef HAVE_WRITEV
- int b = iovcnt - cnt; /* Buffers to write */
- /* Use as many buffers as MAXIOV allows */
- if (b > MAXIOV)
- b = MAXIOV;
- if (b > 1) {
- do {
- w = writev(fd, &iov[cnt], b);
- } while (w < 0 && errno == EINTR);
- } else
- /* Degenerated io vector - use regular write */
- #endif
- {
- do {
- w = write(fd, iov[cnt].iov_base, iov[cnt].iov_len);
- } while (w < 0 && errno == EINTR);
- ASSERT(w <= iov[cnt].iov_len);
- }
- if (w < 0) return check_error(-1, errInfo);
- /* Move forward to next buffer to write */
- for (; cnt < iovcnt && w > 0; cnt++) {
- if (iov[cnt].iov_base && iov[cnt].iov_len > 0) {
- if (w < iov[cnt].iov_len) {
- /* Adjust the buffer for next write */
- iov[cnt].iov_len -= w;
- iov[cnt].iov_base = ((char *)iov[cnt].iov_base) + w;
- w = 0;
- break;
- } else {
- w -= iov[cnt].iov_len;
- }
- }
- }
- ASSERT(w == 0);
- } /* else Non-empty buffer */
- } /* while (cnt< iovcnt) */
- return 1;
- }
- int
- efile_read(Efile_error* errInfo, /* Where to return error codes. */
- int flags, /* Flags given when file was opened. */
- int fd, /* File descriptor to read from. */
- char* buf, /* Buffer to read into. */
- size_t count, /* Number of bytes to read. */
- size_t *pBytesRead) /* Where to return number of
- bytes read. */
- {
- ssize_t n;
- for (;;) {
- if ((n = read(fd, buf, count)) >= 0)
- break;
- else if (errno != EINTR)
- return check_error(-1, errInfo);
- }
- *pBytesRead = (size_t) n;
- return 1;
- }
- /* pread() and pwrite() */
- /* Some unix systems, notably Solaris has these syscalls */
- /* It is especially nice for i.e. the dets module to have support */
- /* for this, even if the underlying OS dosn't support it, it is */
- /* reasonably easy to work around by first calling seek, and then */
- /* calling read(). */
- /* This later strategy however changes the file pointer, which pread() */
- /* does not do. We choose to ignore this and say that the location */
- /* of the file pointer is undefined after a call to any of the p functions*/
- int
- efile_pread(Efile_error* errInfo, /* Where to return error codes. */
- int fd, /* File descriptor to read from. */
- Sint64 offset, /* Offset in bytes from BOF. */
- char* buf, /* Buffer to read into. */
- size_t count, /* Number of bytes to read. */
- size_t *pBytesRead) /* Where to return
- number of bytes read. */
- {
- #if defined(HAVE_PREAD) && defined(HAVE_PWRITE)
- ssize_t n;
- off_t off = (off_t) offset;
- if (off != offset) {
- errno = EINVAL;
- return check_error(-1, errInfo);
- }
- for (;;) {
- if ((n = pread(fd, buf, count, offset)) >= 0)
- break;
- else if (errno != EINTR)
- return check_error(-1, errInfo);
- }
- *pBytesRead = (size_t) n;
- return 1;
- #else
- {
- int res = efile_seek(errInfo, fd, offset, EFILE_SEEK_SET, NULL);
- if (res) {
- return efile_read(errInfo, 0, fd, buf, count, pBytesRead);
- } else {
- return res;
- }
- }
- #endif
- }
- int
- efile_pwrite(Efile_error* errInfo, /* Where to return error codes. */
- int fd, /* File descriptor to write to. */
- char* buf, /* Buffer to write. */
- size_t count, /* Number of bytes to write. */
- Sint64 offset) /* where to write it */
- {
- #if defined(HAVE_PREAD) && defined(HAVE_PWRITE)
- ssize_t written; /* Bytes written in last operation. */
- off_t off = (off_t) offset;
- if (off != offset) {
- errno = EINVAL;
- return check_error(-1, errInfo);
- }
-
- while (count > 0) {
- if ((written = pwrite(fd, buf, count, offset)) < 0) {
- if (errno != EINTR)
- return check_error(-1, errInfo);
- else
- written = 0;
- }
- ASSERT(written <= count);
- buf += written;
- count -= written;
- offset += written;
- }
- return 1;
- #else /* For unix systems that don't support pread() and pwrite() */
- {
- int res = efile_seek(errInfo, fd, offset, EFILE_SEEK_SET, NULL);
-
- if (res) {
- return efile_write(errInfo, 0, fd, buf, count);
- } else {
- return res;
- }
- }
- #endif
- }
- int
- efile_seek(Efile_error* errInfo, /* Where to return error codes. */
- int fd, /* File descriptor to do the seek on. */
- Sint64 offset, /* Offset in bytes from the given
- origin. */
- int origin, /* Origin of seek (SEEK_SET, SEEK_CUR,
- SEEK_END). */
- Sint64 *new_location) /* Resulting new location in file. */
- {
- off_t off, result;
- switch (origin) {
- case EFILE_SEEK_SET: origin = SEEK_SET; break;
- case EFILE_SEEK_CUR: origin = SEEK_CUR; break;
- case EFILE_SEEK_END: origin = SEEK_END; break;
- default:
- errno = EINVAL;
- return check_error(-1, errInfo);
- }
- off = (off_t) offset;
- if (off != offset) {
- errno = EINVAL;
- return check_error(-1, errInfo);
- }
-
- errno = 0;
- result = lseek(fd, off, origin);
- /*
- * Note that the man page for lseek (on SunOs 5) says:
- *
- * "if fildes is a remote file descriptor and offset is
- * negative, lseek() returns the file pointer even if it is
- * negative."
- */
- if (result < 0 && errno == 0)
- errno = EINVAL;
- if (result < 0)
- return check_error(-1, errInfo);
- if (new_location) {
- *new_location = result;
- }
- return 1;
- }
- int
- efile_truncate_file(Efile_error* errInfo, int *fd, int flags)
- {
- #ifndef NO_FTRUNCATE
- off_t offset;
- return check_error((offset = lseek(*fd, 0, 1)) >= 0 &&
- ftruncate(*fd, offset) == 0 ? 1 : -1,
- errInfo);
- #else
- return 1;
- #endif
- }
- int
- efile_readlink(Efile_error* errInfo, char* name, char* buffer, size_t size)
- {
- int len;
- ASSERT(size > 0);
- len = readlink(name, buffer, size-1);
- if (len == -1) {
- return check_error(-1, errInfo);
- }
- buffer[len] = '\0';
- return 1;
- }
- int
- efile_altname(Efile_error* errInfo, char* name, char* buffer, size_t size)
- {
- errno = ENOTSUP;
- return check_error(-1, errInfo);
- }
- int
- efile_link(Efile_error* errInfo, char* old, char* new)
- {
- return check_error(link(old, new), errInfo);
- }
- int
- efile_symlink(Efile_error* errInfo, char* old, char* new)
- {
- return check_error(symlink(old, new), errInfo);
- }
- int
- efile_fadvise(Efile_error* errInfo, int fd, Sint64 offset,
- Sint64 length, int advise)
- {
- #ifdef HAVE_POSIX_FADVISE
- return check_error(posix_fadvise(fd, offset, length, advise), errInfo);
- #else
- return check_error(0, errInfo);
- #endif
- }
- #ifdef HAVE_SENDFILE
- /* For some reason the maximum size_t cannot be used as the max size
- 3GB seems to work on all platforms */
- #define SENDFILE_CHUNK_SIZE ((1UL << 30) -1)
- /*
- * sendfile: The implementation of the sendfile system call varies
- * a lot on different *nix platforms so to make the api similar in all
- * we have to emulate some things in linux and play with variables on
- * bsd/darwin.
- *
- * All of the calls will split a command which tries to send more than
- * SENDFILE_CHUNK_SIZE of data at once.
- *
- * On platforms where *nbytes of 0 does not mean the entire file, this is
- * simulated.
- *
- * It could be possible to implement header/trailer in sendfile. Though
- * you would have to emulate it in linux and on BSD/Darwin some complex
- * calculations have to be made when using a non blocking socket to figure
- * out how much of the header/file/trailer was sent in each command.
- *
- * The semantics of the API is this:
- * Return value: 1 if all data was sent and the function does not need to
- * be called again. 0 if an error occures OR if there is more data which
- * has to be sent (EAGAIN or EINTR will be set appropriately)
- *
- * The amount of data written in a call is returned through nbytes.
- *
- */
- int
- efile_sendfile(Efile_error* errInfo, int in_fd, int out_fd,
- off_t *offset, Uint64 *nbytes, struct t_sendfile_hdtl* hdtl)
- {
- Uint64 written = 0;
- #if defined(__linux__)
- ssize_t retval;
- do {
- /* check if *nbytes is 0 or greater than chunk size */
- if (*nbytes == 0 || *nbytes > SENDFILE_CHUNK_SIZE)
- retval = sendfile(out_fd, in_fd, offset, SENDFILE_CHUNK_SIZE);
- else
- retval = sendfile(out_fd, in_fd, offset, *nbytes);
- if (retval > 0) {
- written += retval;
- *nbytes -= retval;
- }
- } while (retval == SENDFILE_CHUNK_SIZE);
- if (written != 0) {
- /* -1 is not returned by the linux API so we have to simulate it */
- retval = -1;
- errno = EAGAIN;
- }
- #elif defined(__sun) && defined(__SVR4) && defined(HAVE_SENDFILEV)
- ssize_t retval;
- size_t len;
- sendfilevec_t fdrec;
- fdrec.sfv_fd = in_fd;
- fdrec.sfv_flag = 0;
- do {
- fdrec.sfv_off = *offset;
- len = 0;
- /* check if *nbytes is 0 or greater than chunk size */
- if (*nbytes == 0 || *nbytes > SENDFILE_CHUNK_SIZE)
- fdrec.sfv_len = SENDFILE_CHUNK_SIZE;
- else
- fdrec.sfv_len = *nbytes;
- retval = sendfilev(out_fd, &fdrec, 1, &len);
- /* Sometimes sendfilev can return -1 and still send data.
- When that happens we just pretend that no error happend. */
- if (retval != -1 || errno == EAGAIN || errno == EINTR ||
- len != 0) {
- *offset += len;
- *nbytes -= len;
- written += len;
- if (errno != EAGAIN && errno != EINTR && len != 0)
- retval = len;
- }
- } while (len == SENDFILE_CHUNK_SIZE);
- #elif defined(DARWIN)
- int retval;
- off_t len;
- do {
- /* check if *nbytes is 0 or greater than chunk size */
- if(*nbytes > SENDFILE_CHUNK_SIZE)
- len = SENDFILE_CHUNK_SIZE;
- else
- len = *nbytes;
- retval = sendfile(in_fd, out_fd, *offset, &len, NULL, 0);
- if (retval != -1 || errno == EAGAIN || errno == EINTR) {
- *offset += len;
- *nbytes -= len;
- written += len;
- }
- } while (len == SENDFILE_CHUNK_SIZE);
- #elif defined(__FreeBSD__) || defined(__DragonFly__)
- off_t len;
- int retval;
- do {
- if (*nbytes > SENDFILE_CHUNK_SIZE)
- retval = sendfile(in_fd, out_fd, *offset, SENDFILE_CHUNK_SIZE,
- NULL, &len, 0);
- else
- retval = sendfile(in_fd, out_fd, *offset, *nbytes, NULL, &len, 0);
- if (retval != -1 || errno == EAGAIN || errno == EINTR) {
- *offset += len;
- *nbytes -= len;
- written += len;
- }
- } while(len == SENDFILE_CHUNK_SIZE);
- #endif
- *nbytes = written;
- return check_error(retval, errInfo);
- }
- #endif /* HAVE_SENDFILE */
- #ifdef HAVE_POSIX_FALLOCATE
- static int
- call_posix_fallocate(int fd, Sint64 offset, Sint64 length)
- {
- int ret;
- /*
- * On Linux and Solaris for example, posix_fallocate() returns
- * a positive error number on error and it does not set errno.
- * On FreeBSD however (9.0 at least), it returns -1 on error
- * and it sets errno.
- */
- do {
- ret = posix_fallocate(fd, (off_t) offset, (off_t) length);
- if (ret > 0) {
- errno = ret;
- ret = -1;
- }
- } while (ret != 0 && errno == EINTR);
- return ret;
- }
- #endif /* HAVE_POSIX_FALLOCATE */
- int
- efile_fallocate(Efile_error* errInfo, int fd, Sint64 offset, Sint64 length)
- {
- #if defined HAVE_FALLOCATE
- /* Linux specific, more efficient than posix_fallocate. */
- int ret;
- do {
- ret = fallocate(fd, FALLOC_FL_KEEP_SIZE, (off_t) offset, (off_t) length);
- } while (ret != 0 && errno == EINTR);
- #if defined HAVE_POSIX_FALLOCATE
- /* Fallback to posix_fallocate if available. */
- if (ret != 0) {
- ret = call_posix_fallocate(fd, offset, length);
- }
- #endif
- return check_error(ret, errInfo);
- #elif defined F_PREALLOCATE
- /* Mac OS X specific, equivalent to posix_fallocate. */
- int ret;
- fstore_t fs;
- memset(&fs, 0, sizeof(fs));
- fs.fst_flags = F_ALLOCATECONTIG;
- fs.fst_posmode = F_VOLPOSMODE;
- fs.fst_offset = (off_t) offset;
- fs.fst_length = (off_t) length;
- ret = fcntl(fd, F_PREALLOCATE, &fs);
- if (-1 == ret) {
- fs.fst_flags = F_ALLOCATEALL;
- ret = fcntl(fd, F_PREALLOCATE, &fs);
- #if defined HAVE_POSIX_FALLOCATE
- /* Fallback to posix_fallocate if available. */
- if (-1 == ret) {
- ret = call_posix_fallocate(fd, offset, length);
- }
- #endif
- }
- return check_error(ret, errInfo);
- #elif defined HAVE_POSIX_FALLOCATE
- /* Other Unixes, use posix_fallocate if available. */
- return check_error(call_posix_fallocate(fd, offset, length), errInfo);
- #else
- errno = ENOTSUP;
- return check_error(-1, errInfo);
- #endif
- }