diff options
Diffstat (limited to 'sshfs.c')
| -rw-r--r-- | sshfs.c | 30 |
1 files changed, 23 insertions, 7 deletions
@@ -216,6 +216,7 @@ struct sshfs { int rename_workaround; int truncate_workaround; int buflimit_workaround; + int unrel_append; int fstat_workaround; int transform_symlinks; int follow_symlinks; @@ -409,6 +410,7 @@ static struct fuse_opt sshfs_opts[] = { SSHFS_OPT("dir_cache=no", dir_cache, 0), SSHFS_OPT("writeback_cache=yes", writeback_cache, 1), SSHFS_OPT("writeback_cache=no", writeback_cache, 0), + SSHFS_OPT("unreliable_append", unrel_append, 1), SSHFS_OPT("-h", show_help, 1), SSHFS_OPT("--help", show_help, 1), @@ -2500,6 +2502,24 @@ static int sshfs_open_common(const char *path, mode_t mode, if (sshfs.dir_cache) wrctr = cache_get_write_ctr(); + /* With writeback cache, kernel may send read requests even + when userspace opened write-only */ + if (sshfs.writeback_cache && + (fi->flags & O_ACCMODE) == O_WRONLY) { + fi->flags &= ~O_ACCMODE; + fi->flags |= O_RDWR; + } + + /* Having the kernel handle O_APPEND doesn't work reliably, if + the file changes on the server at the wrong time, we will + overwrite data instead of appending. */ + if ((fi->flags & O_APPEND) && sshfs.writeback_cache) { + if(sshfs.unrel_append) + fi->flags &= ~O_APPEND; + else + return -EINVAL; + } + if ((fi->flags & O_ACCMODE) == O_RDONLY) pflags = SSH_FXF_READ; else if((fi->flags & O_ACCMODE) == O_WRONLY) @@ -3344,6 +3364,7 @@ static void usage(const char *progname) " -o sshfs_sync synchronous writes\n" " -o no_readahead synchronous reads (no speculative readahead)\n" " -o sync_readdir synchronous readdir\n" +" -o unreliable_append Enable (unreliable) O_APPEND support\n" " -d, --debug print some debugging information (implies -f)\n" " -o writeback_cache=BOOL enable writeback cache {yes,no} (default: yes)\n" " -o dir_cache=BOOL enable caching of directory contents (names,\n" @@ -3855,7 +3876,8 @@ int main(int argc, char *argv[]) sshfs.wfd = -1; sshfs.ptyfd = -1; sshfs.dir_cache = 1; - sshfs.writeback_cache = 0; + sshfs.writeback_cache = 1; + sshfs.unrel_append = 0; sshfs.show_help = 0; sshfs.show_version = 0; sshfs.singlethread = 0; @@ -3904,12 +3926,6 @@ int main(int argc, char *argv[]) exit(1); } - if(sshfs.writeback_cache) { - printf("NOTICE: writeback cache is disabled in this release due to potential\n" - "dataloss. It will be re-enabled in a future SSHFS release.\n"); - sshfs.writeback_cache = 0; - } - if (sshfs.idmap == IDMAP_USER) sshfs.detect_uid = 1; else if (sshfs.idmap == IDMAP_FILE) { |