From dfd1520d3ab98cfa376f2d84ed1e7887d013720d Mon Sep 17 00:00:00 2001 From: Lennart Poettering Date: Thu, 8 Jan 2015 01:25:40 +0100 Subject: [PATCH] import: also set NOCOW for gpt disk images Given the write patterns on disk images, we better should turn COW off for them. In particular as the file systems used inside the disk images should do their own data integrity checks anyway and we don't need multiple layers of it. --- src/import/import-gpt.c | 11 ++++++++++- 1 file changed, 10 insertions(+), 1 deletion(-) diff --git a/src/import/import-gpt.c b/src/import/import-gpt.c index a85ceee33..d304a399f 100644 --- a/src/import/import-gpt.c +++ b/src/import/import-gpt.c @@ -20,6 +20,7 @@ ***/ #include +#include #include #include "hashmap.h" @@ -165,7 +166,7 @@ static void gpt_import_file_success(GptImportFile *f) { f->disk_fd = open(f->final_path, O_RDONLY|O_NOCTTY|O_CLOEXEC); if (f->disk_fd < 0) { - r = log_error_errno(errno, "Failed top open vendor image: %m"); + r = log_error_errno(errno, "Failed to open vendor image: %m"); goto finish; } } @@ -186,6 +187,14 @@ static void gpt_import_file_success(GptImportFile *f) { goto finish; } + /* Turn off COW writing. This should greatly improve + * performance on COW file systems like btrfs, since it + * reduces fragmentation caused by not allowing in-place + * writes. */ + r = chattr_fd(dfd, true, FS_NOCOW_FL); + if (r < 0) + log_warning_errno(errno, "Failed to set file attributes on %s: %m", f->temp_path); + r = copy_bytes(f->disk_fd, dfd, (off_t) -1, true); if (r < 0) { log_error_errno(r, "Failed to make writable copy of image: %m"); -- 2.30.2