copy: change the various copy_xyz() calls to take a unified flags parameter

This adds a unified "copy_flags" parameter to all copy_xyz() function
calls, replacing the various boolean flags so far used. This should make
many invocations more readable as it is clear what behaviour is
precisely requested. This also prepares ground for adding support for
more modes later on.

3 files changed, 40 insertions, 34 deletions

diff --git a/src/basic/copy.c b/src/basic/copy.c
index 20078a81e..b0a093f48 100644
--- a/src/basic/copy.c
+++ b/src/basic/copy.c
@@ -67,7 +67,7 @@ static ssize_t try_copy_file_range(int fd_in, loff_t *off_in,
                 return -errno;
 }
 
-int copy_bytes(int fdf, int fdt, uint64_t max_bytes, bool try_reflink) {
+int copy_bytes(int fdf, int fdt, uint64_t max_bytes, CopyFlags copy_flags) {
         bool try_cfr = true, try_sendfile = true, try_splice = true;
         int r;
         size_t m = SSIZE_MAX; /* that is the maximum that sendfile and c_f_r accept */
@@ -77,7 +77,7 @@ int copy_bytes(int fdf, int fdt, uint64_t max_bytes, bool try_reflink) {
 
 #if 0 /// UNNEEDED by elogind
         /* Try btrfs reflinks first. */
-        if (try_reflink &&
+        if ((copy_flags & COPY_REFLINK) &&
             max_bytes == (uint64_t) -1 &&
             lseek(fdf, 0, SEEK_CUR) == 0 &&
             lseek(fdt, 0, SEEK_CUR) == 0) {
@@ -199,7 +199,7 @@ static int fd_copy_symlink(int df, const char *from, const struct stat *st, int
         return 0;
 }
 
-static int fd_copy_regular(int df, const char *from, const struct stat *st, int dt, const char *to) {
+static int fd_copy_regular(int df, const char *from, const struct stat *st, int dt, const char *to, CopyFlags copy_flags) {
         _cleanup_close_ int fdf = -1, fdt = -1;
         struct timespec ts[2];
         int r, q;
@@ -216,7 +216,7 @@ 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, (uint64_t) -1, true);
+        r = copy_bytes(fdf, fdt, (uint64_t) -1, copy_flags);
         if (r < 0) {
                 unlinkat(dt, to, 0);
                 return r;
@@ -292,7 +292,7 @@ static int fd_copy_directory(
                 int dt,
                 const char *to,
                 dev_t original_device,
-                bool merge) {
+                CopyFlags copy_flags) {
 
         _cleanup_close_ int fdf = -1, fdt = -1;
         _cleanup_closedir_ DIR *d = NULL;
@@ -318,7 +318,7 @@ static int fd_copy_directory(
         r = mkdirat(dt, to, st->st_mode & 07777);
         if (r >= 0)
                 created = true;
-        else if (errno == EEXIST && merge)
+        else if (errno == EEXIST && (copy_flags & COPY_MERGE))
                 created = false;
         else
                 return -errno;
@@ -345,9 +345,9 @@ static int fd_copy_directory(
                         continue;
 
                 if (S_ISREG(buf.st_mode))
-                        q = fd_copy_regular(dirfd(d), de->d_name, &buf, fdt, de->d_name);
+                        q = fd_copy_regular(dirfd(d), de->d_name, &buf, fdt, de->d_name, copy_flags);
                 else if (S_ISDIR(buf.st_mode))
-                        q = fd_copy_directory(dirfd(d), de->d_name, &buf, fdt, de->d_name, original_device, merge);
+                        q = fd_copy_directory(dirfd(d), de->d_name, &buf, fdt, de->d_name, original_device, copy_flags);
                 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))
@@ -357,7 +357,7 @@ static int fd_copy_directory(
                 else
                         q = -EOPNOTSUPP;
 
-                if (q == -EEXIST && merge)
+                if (q == -EEXIST && (copy_flags & COPY_MERGE))
                         q = 0;
 
                 if (q < 0)
@@ -383,7 +383,7 @@ static int fd_copy_directory(
         return r;
 }
 
-int copy_tree_at(int fdf, const char *from, int fdt, const char *to, bool merge) {
+int copy_tree_at(int fdf, const char *from, int fdt, const char *to, CopyFlags copy_flags) {
         struct stat st;
 
         assert(from);
@@ -393,9 +393,9 @@ int copy_tree_at(int fdf, const char *from, int fdt, const char *to, bool merge)
                 return -errno;
 
         if (S_ISREG(st.st_mode))
-                return fd_copy_regular(fdf, from, &st, fdt, to);
+                return fd_copy_regular(fdf, from, &st, fdt, to, copy_flags);
         else if (S_ISDIR(st.st_mode))
-                return fd_copy_directory(fdf, from, &st, fdt, to, st.st_dev, merge);
+                return fd_copy_directory(fdf, from, &st, fdt, to, st.st_dev, copy_flags);
         else if (S_ISLNK(st.st_mode))
                 return fd_copy_symlink(fdf, from, &st, fdt, to);
         else if (S_ISFIFO(st.st_mode))
@@ -406,11 +406,11 @@ int copy_tree_at(int fdf, const char *from, int fdt, const char *to, bool merge)
                 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_tree(const char *from, const char *to, CopyFlags copy_flags) {
+        return copy_tree_at(AT_FDCWD, from, AT_FDCWD, to, copy_flags);
 }
 
-int copy_directory_fd(int dirfd, const char *to, bool merge) {
+int copy_directory_fd(int dirfd, const char *to, CopyFlags copy_flags) {
         struct stat st;
 
         assert(dirfd >= 0);
@@ -422,10 +422,10 @@ int copy_directory_fd(int dirfd, const char *to, bool merge) {
         if (!S_ISDIR(st.st_mode))
                 return -ENOTDIR;
 
-        return fd_copy_directory(dirfd, NULL, &st, AT_FDCWD, to, st.st_dev, merge);
+        return fd_copy_directory(dirfd, NULL, &st, AT_FDCWD, to, st.st_dev, copy_flags);
 }
 
-int copy_directory(const char *from, const char *to, bool merge) {
+int copy_directory(const char *from, const char *to, CopyFlags copy_flags) {
         struct stat st;
 
         assert(from);
@@ -437,10 +437,10 @@ int copy_directory(const char *from, const char *to, bool merge) {
         if (!S_ISDIR(st.st_mode))
                 return -ENOTDIR;
 
-        return fd_copy_directory(AT_FDCWD, from, &st, AT_FDCWD, to, st.st_dev, merge);
+        return fd_copy_directory(AT_FDCWD, from, &st, AT_FDCWD, to, st.st_dev, copy_flags);
 }
 
-int copy_file_fd(const char *from, int fdt, bool try_reflink) {
+int copy_file_fd(const char *from, int fdt, CopyFlags copy_flags) {
         _cleanup_close_ int fdf = -1;
         int r;
 
@@ -451,7 +451,7 @@ int copy_file_fd(const char *from, int fdt, bool try_reflink) {
         if (fdf < 0)
                 return -errno;
 
-        r = copy_bytes(fdf, fdt, (uint64_t) -1, try_reflink);
+        r = copy_bytes(fdf, fdt, (uint64_t) -1, copy_flags);
 
         (void) copy_times(fdf, fdt);
         (void) copy_xattr(fdf, fdt);
@@ -459,7 +459,7 @@ int copy_file_fd(const char *from, int fdt, bool try_reflink) {
         return r;
 }
 
-int copy_file(const char *from, const char *to, int flags, mode_t mode, unsigned chattr_flags) {
+int copy_file(const char *from, const char *to, int flags, mode_t mode, unsigned chattr_flags, CopyFlags copy_flags) {
         int fdt = -1, r;
 
         assert(from);
@@ -474,7 +474,7 @@ int copy_file(const char *from, const char *to, int flags, mode_t mode, unsigned
         if (chattr_flags != 0)
                 (void) chattr_fd(fdt, chattr_flags, (unsigned) -1);
 
-        r = copy_file_fd(from, fdt, true);
+        r = copy_file_fd(from, fdt, copy_flags);
         if (r < 0) {
                 close(fdt);
                 unlink(to);
@@ -489,7 +489,7 @@ int copy_file(const char *from, const char *to, int flags, mode_t mode, unsigned
         return 0;
 }
 
-int copy_file_atomic(const char *from, const char *to, mode_t mode, bool replace, unsigned chattr_flags) {
+int copy_file_atomic(const char *from, const char *to, mode_t mode, unsigned chattr_flags, CopyFlags copy_flags) {
         _cleanup_free_ char *t = NULL;
         int r;
 
@@ -500,11 +500,11 @@ int copy_file_atomic(const char *from, const char *to, mode_t mode, bool replace
         if (r < 0)
                 return r;
 
-        r = copy_file(from, t, O_NOFOLLOW|O_EXCL, mode, chattr_flags);
+        r = copy_file(from, t, O_NOFOLLOW|O_EXCL, mode, chattr_flags, copy_flags);
         if (r < 0)
                 return r;
 
-        if (replace) {
+        if (copy_flags & COPY_REPLACE) {
                 r = renameat(AT_FDCWD, t, AT_FDCWD, to);
                 if (r < 0)
                         r = -errno;
diff --git a/src/basic/copy.h b/src/basic/copy.h
index 41aad741c..3125ffec6 100644
--- a/src/basic/copy.h
+++ b/src/basic/copy.h
@@ -25,16 +25,22 @@
 #include <sys/types.h>
 
 #if 0 /// UNNEEDED by elogind
-int copy_file_fd(const char *from, int to, bool try_reflink);
-int copy_file(const char *from, const char *to, int flags, mode_t mode, unsigned chattr_flags);
-int copy_file_atomic(const char *from, const char *to, mode_t mode, bool replace, unsigned chattr_flags);
-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);
-int copy_directory_fd(int dirfd, const char *to, bool merge);
-int copy_directory(const char *from, const char *to, bool merge);
 #endif // 0
-int copy_bytes(int fdf, int fdt, uint64_t max_bytes, bool try_reflink);
 #if 0 /// UNNEEDED by elogind
+typedef enum CopyFlags {
+        COPY_REFLINK    = 0x1,      /* try to reflink */
+        COPY_MERGE      = 0x2,      /* merge existing trees with our new one to copy */
+        COPY_REPLACE    = 0x4,      /* replace an existing file if there's one */
+} CopyFlags;
+
+int copy_file_fd(const char *from, int to, CopyFlags copy_flags);
+int copy_file(const char *from, const char *to, int open_flags, mode_t mode, unsigned chattr_flags, CopyFlags copy_flags);
+int copy_file_atomic(const char *from, const char *to, mode_t mode, unsigned chattr_flags, CopyFlags copy_flags);
+int copy_tree(const char *from, const char *to, CopyFlags copy_flags);
+int copy_tree_at(int fdf, const char *from, int fdt, const char *to, CopyFlags copy_flags);
+int copy_directory_fd(int dirfd, const char *to, CopyFlags copy_flags);
+int copy_directory(const char *from, const char *to, CopyFlags copy_flags);
+int copy_bytes(int fdf, int fdt, uint64_t max_bytes, CopyFlags copy_flags);
 int copy_times(int fdf, int fdt);
 int copy_xattr(int fdf, int fdt);
 #endif // 0
diff --git a/src/shared/pager.c b/src/shared/pager.c
index 184a0f578..82f929416 100644
--- a/src/shared/pager.c
+++ b/src/shared/pager.c
@@ -44,7 +44,7 @@ static pid_t pager_pid = 0;
 noreturn static void pager_fallback(void) {
         int r;
 
-        r = copy_bytes(STDIN_FILENO, STDOUT_FILENO, (uint64_t) -1, false);
+        r = copy_bytes(STDIN_FILENO, STDOUT_FILENO, (uint64_t) -1, 0);
         if (r < 0) {
                 log_error_errno(r, "Internal pager failed: %m");
                 _exit(EXIT_FAILURE);