diff options
author | Luke Shumaker <lukeshu@sbcglobal.net> | 2016-06-02 13:16:04 -0400 |
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committer | Luke Shumaker <lukeshu@sbcglobal.net> | 2016-06-02 13:16:04 -0400 |
commit | fccd290a8373438c26ed4e4f8130db18eb9b3dfe (patch) | |
tree | 2f032e1b125aa88e456644de865e9f42fffa4150 /src/libbasic/copy.c | |
parent | 6169d05b4a456e26a0197242464e3e2bca12a29d (diff) |
./move.sh
Diffstat (limited to 'src/libbasic/copy.c')
-rw-r--r-- | src/libbasic/copy.c | 548 |
1 files changed, 548 insertions, 0 deletions
diff --git a/src/libbasic/copy.c b/src/libbasic/copy.c new file mode 100644 index 0000000000..519b412941 --- /dev/null +++ b/src/libbasic/copy.c @@ -0,0 +1,548 @@ +/*** + This file is part of systemd. + + Copyright 2014 Lennart Poettering + + systemd is free software; you can redistribute it and/or modify it + under the terms of the GNU Lesser General Public License as published by + the Free Software Foundation; either version 2.1 of the License, or + (at your option) any later version. + + systemd is distributed in the hope that it will be useful, but + WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public License + along with systemd; If not, see <http://www.gnu.org/licenses/>. +***/ + +#include <dirent.h> +#include <errno.h> +#include <fcntl.h> +#include <stddef.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <sys/sendfile.h> +#include <sys/stat.h> +#include <sys/xattr.h> +#include <time.h> +#include <unistd.h> + +#include "alloc-util.h" +#include "btrfs-util.h" +#include "chattr-util.h" +#include "copy.h" +#include "dirent-util.h" +#include "fd-util.h" +#include "fileio.h" +#include "fs-util.h" +#include "io-util.h" +#include "macro.h" +#include "string-util.h" +#include "strv.h" +#include "time-util.h" +#include "umask-util.h" +#include "xattr-util.h" + +#define COPY_BUFFER_SIZE (16*1024) + +int copy_bytes(int fdf, int fdt, uint64_t max_bytes, bool try_reflink) { + bool try_sendfile = true, try_splice = true; + int r; + + assert(fdf >= 0); + assert(fdt >= 0); + + /* Try btrfs reflinks first. */ + if (try_reflink && + max_bytes == (uint64_t) -1 && + lseek(fdf, 0, SEEK_CUR) == 0 && + lseek(fdt, 0, SEEK_CUR) == 0) { + + r = btrfs_reflink(fdf, fdt); + if (r >= 0) + return 0; /* we copied the whole thing, hence hit EOF, return 0 */ + } + + for (;;) { + size_t m = COPY_BUFFER_SIZE; + ssize_t n; + + if (max_bytes != (uint64_t) -1) { + + if (max_bytes <= 0) + return 1; /* return > 0 if we hit the max_bytes limit */ + + if ((uint64_t) m > max_bytes) + m = (size_t) max_bytes; + } + + /* First try sendfile(), unless we already tried */ + if (try_sendfile) { + + n = sendfile(fdt, fdf, NULL, m); + if (n < 0) { + if (errno != EINVAL && errno != ENOSYS) + return -errno; + + try_sendfile = false; + /* use fallback below */ + } else if (n == 0) /* EOF */ + break; + else if (n > 0) + /* Success! */ + goto next; + } + + /* The try splice, unless we already tried */ + if (try_splice) { + n = splice(fdf, NULL, fdt, NULL, m, 0); + if (n < 0) { + if (errno != EINVAL && errno != ENOSYS) + return -errno; + + try_splice = false; + /* use fallback below */ + } else if (n == 0) /* EOF */ + break; + else if (n > 0) + /* Success! */ + goto next; + } + + /* As a fallback just copy bits by hand */ + { + uint8_t buf[m]; + + n = read(fdf, buf, m); + if (n < 0) + return -errno; + if (n == 0) /* EOF */ + break; + + r = loop_write(fdt, buf, (size_t) n, false); + if (r < 0) + return r; + } + + next: + if (max_bytes != (uint64_t) -1) { + assert(max_bytes >= (uint64_t) n); + max_bytes -= n; + } + } + + return 0; /* return 0 if we hit EOF earlier than the size limit */ +} + +static int fd_copy_symlink(int df, const char *from, const struct stat *st, int dt, const char *to) { + _cleanup_free_ char *target = NULL; + int r; + + assert(from); + assert(st); + assert(to); + + r = readlinkat_malloc(df, from, &target); + if (r < 0) + return r; + + if (symlinkat(target, dt, to) < 0) + return -errno; + + if (fchownat(dt, to, st->st_uid, st->st_gid, AT_SYMLINK_NOFOLLOW) < 0) + return -errno; + + return 0; +} + +static int fd_copy_regular(int df, const char *from, const struct stat *st, int dt, const char *to) { + _cleanup_close_ int fdf = -1, fdt = -1; + struct timespec ts[2]; + int r, q; + + assert(from); + assert(st); + assert(to); + + fdf = openat(df, from, O_RDONLY|O_CLOEXEC|O_NOCTTY|O_NOFOLLOW); + if (fdf < 0) + return -errno; + + fdt = openat(dt, to, O_WRONLY|O_CREAT|O_EXCL|O_CLOEXEC|O_NOCTTY|O_NOFOLLOW, st->st_mode & 07777); + if (fdt < 0) + return -errno; + + r = copy_bytes(fdf, fdt, (uint64_t) -1, true); + if (r < 0) { + unlinkat(dt, to, 0); + return r; + } + + if (fchown(fdt, st->st_uid, st->st_gid) < 0) + r = -errno; + + if (fchmod(fdt, st->st_mode & 07777) < 0) + r = -errno; + + ts[0] = st->st_atim; + ts[1] = st->st_mtim; + (void) futimens(fdt, ts); + + (void) copy_xattr(fdf, fdt); + + q = close(fdt); + fdt = -1; + + if (q < 0) { + r = -errno; + unlinkat(dt, to, 0); + } + + return r; +} + +static int fd_copy_fifo(int df, const char *from, const struct stat *st, int dt, const char *to) { + int r; + + assert(from); + assert(st); + assert(to); + + r = mkfifoat(dt, to, st->st_mode & 07777); + if (r < 0) + return -errno; + + if (fchownat(dt, to, st->st_uid, st->st_gid, AT_SYMLINK_NOFOLLOW) < 0) + r = -errno; + + if (fchmodat(dt, to, st->st_mode & 07777, 0) < 0) + r = -errno; + + return r; +} + +static int fd_copy_node(int df, const char *from, const struct stat *st, int dt, const char *to) { + int r; + + assert(from); + assert(st); + assert(to); + + r = mknodat(dt, to, st->st_mode, st->st_rdev); + if (r < 0) + return -errno; + + if (fchownat(dt, to, st->st_uid, st->st_gid, AT_SYMLINK_NOFOLLOW) < 0) + r = -errno; + + if (fchmodat(dt, to, st->st_mode & 07777, 0) < 0) + r = -errno; + + return r; +} + +static int fd_copy_directory( + int df, + const char *from, + const struct stat *st, + int dt, + const char *to, + dev_t original_device, + bool merge) { + + _cleanup_close_ int fdf = -1, fdt = -1; + _cleanup_closedir_ DIR *d = NULL; + struct dirent *de; + bool created; + int r; + + assert(st); + assert(to); + + if (from) + fdf = openat(df, from, O_RDONLY|O_DIRECTORY|O_CLOEXEC|O_NOCTTY|O_NOFOLLOW); + else + fdf = fcntl(df, F_DUPFD_CLOEXEC, 3); + + d = fdopendir(fdf); + if (!d) + return -errno; + fdf = -1; + + r = mkdirat(dt, to, st->st_mode & 07777); + if (r >= 0) + created = true; + else if (errno == EEXIST && merge) + created = false; + else + return -errno; + + fdt = openat(dt, to, O_RDONLY|O_DIRECTORY|O_CLOEXEC|O_NOCTTY|O_NOFOLLOW); + if (fdt < 0) + return -errno; + + r = 0; + + if (created) { + struct timespec ut[2] = { + st->st_atim, + st->st_mtim + }; + + if (fchown(fdt, st->st_uid, st->st_gid) < 0) + r = -errno; + + if (fchmod(fdt, st->st_mode & 07777) < 0) + r = -errno; + + (void) futimens(fdt, ut); + (void) copy_xattr(dirfd(d), fdt); + } + + FOREACH_DIRENT_ALL(de, d, return -errno) { + struct stat buf; + int q; + + if (STR_IN_SET(de->d_name, ".", "..")) + continue; + + if (fstatat(dirfd(d), de->d_name, &buf, AT_SYMLINK_NOFOLLOW) < 0) { + r = -errno; + continue; + } + + if (buf.st_dev != original_device) + continue; + + if (S_ISREG(buf.st_mode)) + q = fd_copy_regular(dirfd(d), de->d_name, &buf, fdt, de->d_name); + else if (S_ISDIR(buf.st_mode)) + q = fd_copy_directory(dirfd(d), de->d_name, &buf, fdt, de->d_name, original_device, merge); + else if (S_ISLNK(buf.st_mode)) + q = fd_copy_symlink(dirfd(d), de->d_name, &buf, fdt, de->d_name); + else if (S_ISFIFO(buf.st_mode)) + q = fd_copy_fifo(dirfd(d), de->d_name, &buf, fdt, de->d_name); + else if (S_ISBLK(buf.st_mode) || S_ISCHR(buf.st_mode)) + q = fd_copy_node(dirfd(d), de->d_name, &buf, fdt, de->d_name); + else + q = -EOPNOTSUPP; + + if (q == -EEXIST && merge) + q = 0; + + if (q < 0) + r = q; + } + + return r; +} + +int copy_tree_at(int fdf, const char *from, int fdt, const char *to, bool merge) { + struct stat st; + + assert(from); + assert(to); + + if (fstatat(fdf, from, &st, AT_SYMLINK_NOFOLLOW) < 0) + return -errno; + + if (S_ISREG(st.st_mode)) + return fd_copy_regular(fdf, from, &st, fdt, to); + else if (S_ISDIR(st.st_mode)) + return fd_copy_directory(fdf, from, &st, fdt, to, st.st_dev, merge); + else if (S_ISLNK(st.st_mode)) + return fd_copy_symlink(fdf, from, &st, fdt, to); + else if (S_ISFIFO(st.st_mode)) + return fd_copy_fifo(fdf, from, &st, fdt, to); + else if (S_ISBLK(st.st_mode) || S_ISCHR(st.st_mode)) + return fd_copy_node(fdf, from, &st, fdt, to); + else + return -EOPNOTSUPP; +} + +int copy_tree(const char *from, const char *to, bool merge) { + return copy_tree_at(AT_FDCWD, from, AT_FDCWD, to, merge); +} + +int copy_directory_fd(int dirfd, const char *to, bool merge) { + + struct stat st; + + assert(dirfd >= 0); + assert(to); + + if (fstat(dirfd, &st) < 0) + return -errno; + + if (!S_ISDIR(st.st_mode)) + return -ENOTDIR; + + return fd_copy_directory(dirfd, NULL, &st, AT_FDCWD, to, st.st_dev, merge); +} + +int copy_file_fd(const char *from, int fdt, bool try_reflink) { + _cleanup_close_ int fdf = -1; + int r; + + assert(from); + assert(fdt >= 0); + + fdf = open(from, O_RDONLY|O_CLOEXEC|O_NOCTTY); + if (fdf < 0) + return -errno; + + r = copy_bytes(fdf, fdt, (uint64_t) -1, try_reflink); + + (void) copy_times(fdf, fdt); + (void) copy_xattr(fdf, fdt); + + return r; +} + +int copy_file(const char *from, const char *to, int flags, mode_t mode, unsigned chattr_flags) { + int fdt = -1, r; + + assert(from); + assert(to); + + RUN_WITH_UMASK(0000) { + fdt = open(to, flags|O_WRONLY|O_CREAT|O_CLOEXEC|O_NOCTTY, mode); + if (fdt < 0) + return -errno; + } + + if (chattr_flags != 0) + (void) chattr_fd(fdt, chattr_flags, (unsigned) -1); + + r = copy_file_fd(from, fdt, true); + if (r < 0) { + close(fdt); + unlink(to); + return r; + } + + if (close(fdt) < 0) { + unlink_noerrno(to); + return -errno; + } + + return 0; +} + +int copy_file_atomic(const char *from, const char *to, mode_t mode, bool replace, unsigned chattr_flags) { + _cleanup_free_ char *t = NULL; + int r; + + assert(from); + assert(to); + + r = tempfn_random(to, NULL, &t); + if (r < 0) + return r; + + r = copy_file(from, t, O_NOFOLLOW|O_EXCL, mode, chattr_flags); + if (r < 0) + return r; + + if (replace) { + r = renameat(AT_FDCWD, t, AT_FDCWD, to); + if (r < 0) + r = -errno; + } else + r = rename_noreplace(AT_FDCWD, t, AT_FDCWD, to); + if (r < 0) { + (void) unlink_noerrno(t); + return r; + } + + return 0; +} + +int copy_times(int fdf, int fdt) { + struct timespec ut[2]; + struct stat st; + usec_t crtime = 0; + + assert(fdf >= 0); + assert(fdt >= 0); + + if (fstat(fdf, &st) < 0) + return -errno; + + ut[0] = st.st_atim; + ut[1] = st.st_mtim; + + if (futimens(fdt, ut) < 0) + return -errno; + + if (fd_getcrtime(fdf, &crtime) >= 0) + (void) fd_setcrtime(fdt, crtime); + + return 0; +} + +int copy_xattr(int fdf, int fdt) { + _cleanup_free_ char *bufa = NULL, *bufb = NULL; + size_t sza = 100, szb = 100; + ssize_t n; + int ret = 0; + const char *p; + + for (;;) { + bufa = malloc(sza); + if (!bufa) + return -ENOMEM; + + n = flistxattr(fdf, bufa, sza); + if (n == 0) + return 0; + if (n > 0) + break; + if (errno != ERANGE) + return -errno; + + sza *= 2; + + bufa = mfree(bufa); + } + + p = bufa; + while (n > 0) { + size_t l; + + l = strlen(p); + assert(l < (size_t) n); + + if (startswith(p, "user.")) { + ssize_t m; + + if (!bufb) { + bufb = malloc(szb); + if (!bufb) + return -ENOMEM; + } + + m = fgetxattr(fdf, p, bufb, szb); + if (m < 0) { + if (errno == ERANGE) { + szb *= 2; + bufb = mfree(bufb); + continue; + } + + return -errno; + } + + if (fsetxattr(fdt, p, bufb, m, 0) < 0) + ret = -errno; + } + + p += l + 1; + n -= l + 1; + } + + return ret; +} |