[PATCH 03/14] copy_fd: pass error message back through a strbuf
- From
Jonathan Nieder <jrnieder@gmail.com>
- Date
- Dec 3, 2014, 05:13 UTC
- Message-ID
- <20141203051344.GM6527@google.com>
- In-Reply-To
- <20141203050217.GJ6527@google.com>
This way, callers can put the message in context or even avoid printing the message altogether.
Currently hold_lock_file_for_append tries to save errno in order to produce a meaningful message about the failure and tries to print a second message using errno. Unfortunately the errno it uses is not meaningful because copy_fd makes no effort to set a meaningful errno value. This change is preparation for simplifying the hold_lock_file_for_append behavior.
No user-visible change intended yet.
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com> --- The title feature.
cache.h | 2 +- convert.c | 6 +++++- copy.c | 32 +++++++++++++++++++++----------- lockfile.c | 6 +++++- 4 files changed, 32 insertions(+), 14 deletions(-)
diff --git a/cache.h b/cache.h index 99ed096..ddaa30f 100644 --- a/cache.h +++ b/cache.h @@ -1479,7 +1479,7 @@ extern const char *git_mailmap_blob; extern void maybe_flush_or_die(FILE *, const char *); __attribute__((format (printf, 2, 3))) extern void fprintf_or_die(FILE *, const char *fmt, ...); -extern int copy_fd(int ifd, int ofd); +extern int copy_fd(int ifd, int ofd, struct strbuf *err); extern int copy_file(const char *dst, const char *src, int mode); extern int copy_file_with_time(const char *dst, const char *src, int mode); extern void write_or_die(int fd, const void *buf, size_t count); diff --git a/convert.c b/convert.c index 9a5612e..e301447 100644 --- a/convert.c +++ b/convert.c @@ -358,7 +358,11 @@ static int filter_buffer_or_fd(int in, int out, void *data) if (params->src) { write_err = (write_in_full(child_process.in, params->src, params->size) < 0); } else { - write_err = copy_fd(params->fd, child_process.in); + struct strbuf err = STRBUF_INIT; + write_err = copy_fd(params->fd, child_process.in, &err); + if (write_err) + error("copy-fd: %s", err.buf); + strbuf_release(&err); } if (close(child_process.in)) diff --git a/copy.c b/copy.c index f2970ec..828661a 100644 --- a/copy.c +++ b/copy.c @@ -1,19 +1,22 @@ #include "cache.h" -int copy_fd(int ifd, int ofd) +int copy_fd(int ifd, int ofd, struct strbuf *err) { + assert(err); + while (1) { char buffer[8192]; ssize_t len = xread(ifd, buffer, sizeof(buffer)); if (!len) break; if (len < 0) { - return error("copy-fd: read returned %s", - strerror(errno)); + strbuf_addf(err, "read returned %s", strerror(errno)); + return -1; + } + if (write_in_full(ofd, buffer, len) < 0) { + strbuf_addf(err, "write returned %s", strerror(errno)); + return -1; } - if (write_in_full(ofd, buffer, len) < 0) - return error("copy-fd: write returned %s", - strerror(errno)); } return 0; } @@ -33,7 +36,8 @@ static int copy_times(const char *dst, const char *src) int copy_file(const char *dst, const char *src, int mode) { - int fdi, fdo, status; + int fdi, fdo; + struct strbuf err = STRBUF_INIT; mode = (mode & 0111) ? 0777 : 0666; if ((fdi = open(src, O_RDONLY)) < 0) @@ -42,15 +46,21 @@ int copy_file(const char *dst, const char *src, int mode) close(fdi); return fdo; } - status = copy_fd(fdi, fdo); + if (copy_fd(fdi, fdo, &err)) { + close(fdi); + close(fdo); + error("copy-fd: %s", err.buf); + strbuf_release(&err); + return -1; + } + strbuf_release(&err); close(fdi); if (close(fdo) != 0) return error("%s: close error: %s", dst, strerror(errno)); - - if (!status && adjust_shared_perm(dst)) + if (adjust_shared_perm(dst)) return -1; - return status; + return 0; } int copy_file_with_time(const char *dst, const char *src, int mode) diff --git a/lockfile.c b/lockfile.c index 4f16ee7..b3020f3 100644 --- a/lockfile.c +++ b/lockfile.c @@ -182,6 +182,7 @@ int hold_lock_file_for_update(struct lock_file *lk, const char *path, int flags) int hold_lock_file_for_append(struct lock_file *lk, const char *path, int flags) { int fd, orig_fd; + struct strbuf err = STRBUF_INIT; fd = lock_file(lk, path, flags); if (fd < 0) { @@ -202,9 +203,11 @@ int hold_lock_file_for_append(struct lock_file *lk, const char *path, int flags) errno = save_errno; return -1; } - } else if (copy_fd(orig_fd, fd)) { + } else if (copy_fd(orig_fd, fd, &err)) { int save_errno = errno; + error("copy-fd: %s", err.buf); + strbuf_release(&err); if (flags & LOCK_DIE_ON_ERROR) exit(128); close(orig_fd); @@ -214,6 +217,7 @@ int hold_lock_file_for_append(struct lock_file *lk, const char *path, int flags) } else { close(orig_fd); } + strbuf_release(&err); return fd; }