X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?p=elogind.git;a=blobdiff_plain;f=src%2Fshared%2Fcopy.c;h=1282cb88be7f076b3e390a3131a301da6c7304c0;hp=7c3fab6901020c0db85520dce2224a85829137c2;hb=01c94c5d0aff09b4c0e429d483c8eeba40017071;hpb=2c455af4c765463c75df79acba34d2347c03cbff

diff --git a/src/shared/copy.c b/src/shared/copy.c
index 7c3fab690..1282cb88b 100644
--- a/src/shared/copy.c
+++ b/src/shared/copy.c
@@ -19,29 +19,79 @@
   along with systemd; If not, see <http://www.gnu.org/licenses/>.
 ***/
 
+#include <sys/sendfile.h>
+#include <sys/xattr.h>
+
 #include "util.h"
+#include "btrfs-util.h"
 #include "copy.h"
 
-int copy_bytes(int fdf, int fdt) {
+#define COPY_BUFFER_SIZE (16*1024)
+
+int copy_bytes(int fdf, int fdt, off_t max_bytes, bool try_reflink) {
+        bool try_sendfile = true;
+        int r;
+
         assert(fdf >= 0);
         assert(fdt >= 0);
 
+        /* Try btrfs reflinks first. */
+        if (try_reflink && max_bytes == (off_t) -1) {
+                r = btrfs_reflink(fdf, fdt);
+                if (r >= 0)
+                        return r;
+        }
+
         for (;;) {
-                char buf[PIPE_BUF];
-                ssize_t n, k;
+                size_t m = COPY_BUFFER_SIZE;
+                ssize_t n;
 
-                n = read(fdf, buf, sizeof(buf));
-                if (n < 0)
-                        return -errno;
-                if (n == 0)
-                        break;
+                if (max_bytes != (off_t) -1) {
+
+                        if (max_bytes <= 0)
+                                return -EFBIG;
+
+                        if ((off_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)
+                                /* Succcess! */
+                                goto next;
+                }
+
+                /* As a fallback just copy bits by hand */
+                {
+                        char buf[m];
 
-                errno = 0;
-                k = loop_write(fdt, buf, n, false);
-                if (k < 0)
-                        return k;
-                if (k != n)
-                        return errno ? -errno : -EIO;
+                        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 != (off_t) -1) {
+                        assert(max_bytes >= n);
+                        max_bytes -= n;
+                }
         }
 
         return 0;
@@ -70,6 +120,7 @@ static int fd_copy_symlink(int df, const char *from, const struct stat *st, int
 
 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);
@@ -84,7 +135,7 @@ static int fd_copy_regular(int df, const char *from, const struct stat *st, int
         if (fdt < 0)
                 return -errno;
 
-        r = copy_bytes(fdf, fdt);
+        r = copy_bytes(fdf, fdt, (off_t) -1, true);
         if (r < 0) {
                 unlinkat(dt, to, 0);
                 return r;
@@ -96,6 +147,12 @@ static int fd_copy_regular(int df, const char *from, const struct stat *st, int
         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;
 
@@ -147,20 +204,28 @@ static int fd_copy_node(int df, const char *from, const struct stat *st, int dt,
         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) {
+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(from);
         assert(st);
         assert(to);
 
-        fdf = openat(df, from, O_RDONLY|O_DIRECTORY|O_CLOEXEC|O_NOCTTY|O_NOFOLLOW);
-        if (fdf < 0)
-                return -errno;
+        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)
@@ -182,11 +247,19 @@ static int fd_copy_directory(int df, const char *from, const struct stat *st, in
         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(de, d, return -errno) {
@@ -212,7 +285,7 @@ static int fd_copy_directory(int df, const char *from, const struct stat *st, in
                 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 = -ENOTSUP;
+                        q = -EOPNOTSUPP;
 
                 if (q == -EEXIST && merge)
                         q = 0;
@@ -224,58 +297,211 @@ static int fd_copy_directory(int df, const char *from, const struct stat *st, in
         return r;
 }
 
-int copy_tree(const char *from, const char *to, bool merge) {
+int copy_tree_at(int fdf, const char *from, int fdt, const char *to, bool merge) {
         struct stat st;
 
         assert(from);
         assert(to);
 
-        if (lstat(from, &st) < 0)
+        if (fstatat(fdf, from, &st, AT_SYMLINK_NOFOLLOW) < 0)
                 return -errno;
 
         if (S_ISREG(st.st_mode))
-                return fd_copy_regular(AT_FDCWD, from, &st, AT_FDCWD, to);
+                return fd_copy_regular(fdf, from, &st, fdt, to);
         else if (S_ISDIR(st.st_mode))
-                return fd_copy_directory(AT_FDCWD, from, &st, AT_FDCWD, to, st.st_dev, merge);
+                return fd_copy_directory(fdf, from, &st, fdt, to, st.st_dev, merge);
         else if (S_ISLNK(st.st_mode))
-                return fd_copy_symlink(AT_FDCWD, from, &st, AT_FDCWD, to);
+                return fd_copy_symlink(fdf, from, &st, fdt, to);
         else if (S_ISFIFO(st.st_mode))
-                return fd_copy_fifo(AT_FDCWD, from, &st, AT_FDCWD, to);
+                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(AT_FDCWD, from, &st, AT_FDCWD, to);
+                return fd_copy_node(fdf, from, &st, fdt, to);
         else
-                return -ENOTSUP;
+                return -EOPNOTSUPP;
 }
 
-int copy_file(const char *from, const char *to, int flags, mode_t mode) {
-        _cleanup_close_ int fdf = -1, fdt = -1;
+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(to);
+        assert(fdt >= 0);
 
         fdf = open(from, O_RDONLY|O_CLOEXEC|O_NOCTTY);
         if (fdf < 0)
                 return -errno;
 
-        fdt = open(to, flags|O_WRONLY|O_CREAT|O_CLOEXEC|O_NOCTTY, mode);
-        if (fdt < 0)
-                return -errno;
+        r = copy_bytes(fdf, fdt, (off_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;
+        }
 
-        r = copy_bytes(fdf, fdt);
+        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;
         }
 
-        r = close(fdt);
-        fdt = -1;
+        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, &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) {
-                r = -errno;
-                unlink(to);
+                (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;
+
+                free(bufa);
+                bufa = NULL;
+        }
+
+        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;
+                                        free(bufb);
+                                        bufb = NULL;
+                                        continue;
+                                }
+
+                                return -errno;
+                        }
+
+                        if (fsetxattr(fdt, p, bufb, m, 0) < 0)
+                                ret = -errno;
+                }
+
+                p += l + 1;
+                n -= l + 1;
+        }
+
+        return ret;
+}