Implement --tweak, --no-tweak, --no-tweak-hlinked options.

[rsync/rsync.git] / rsync.yo

diff --git a/rsync.yo b/rsync.yo
index fdc0e23..8852adf 100644 (file)
--- a/rsync.yo
+++ b/rsync.yo
@@ -329,6 +329,8 @@ to the detailed description below for a complete description.  verb(
      --inplace               update destination files in-place
      --append                append data onto shorter files
      --append-verify         --append w/old data in file checksum
+     --no-tweak              recreate dest files rather than tweak attrs
+     --no-tweak-hlinked      ... if they are hard-linked
  -d, --dirs                  transfer directories without recursing
  -l, --links                 copy symlinks as symlinks
  -L, --copy-links            transform symlink into referent file/dir
@@ -743,6 +745,33 @@ bf(--append-verify), so if you are interacting with an older rsync (or the
 transfer is using a protocol prior to 30), specifying either append option
 will initiate an bf(--append-verify) transfer.
 
+dit(bf(--no-tweak)) If a corresponding source file and destination file
+are determined to have identical data (or symlink target path, etc.) but differ
+in preserved attributes, rsync's default behavior (which can be explicitly
+requested via bf(--tweak)) is to tweak the attributes of the destination file
+in place.  bf(--no-tweak) makes rsync recreate the destination file instead.
+
+You can use bf(--no-tweak) to avoid the race inherent in
+bf(--no-tweak-hlinked) if the destination is subject to concurrent
+modification.  It may also be useful to ensure that, if multiple attributes
+of the destination file need updating, the attributes visible at the
+destination path change simultaneously.  (Caveat: In the current
+implementation, the abbreviated extended attributes of the recreated file
+may be set after it is moved into place.)
+
+This option conflicts with bf(--inplace) and with bf(--append) because those
+combinations don't make sense.
+
+dit(bf(--no-tweak-hlinked)) Like bf(--no-tweak) but only affects destination
+files that have more than one hard link.
+You can use bf(--no-tweak-linked) to safely update a backup that has files
+hard-linked from a previous backup if you are not worried about concurrent
+modification to the destination.
+
+This option currently conflicts with bf(--inplace) and bf(--append).  In
+the future, it might selectively disable those options for multiply linked
+destination files.
+
 dit(bf(-d, --dirs)) Tell the sending side to include any directories that
 are encountered.  Unlike bf(--recursive), a directory's contents are not copied
 unless the directory name specified is "." or ends with a trailing slash