diff options
| -rw-r--r-- | src/journal/journal-file.c | 46 |
1 files changed, 36 insertions, 10 deletions
diff --git a/src/journal/journal-file.c b/src/journal/journal-file.c index a432eb08a6..be6a5522fa 100644 --- a/src/journal/journal-file.c +++ b/src/journal/journal-file.c @@ -2522,6 +2522,41 @@ void journal_file_print_header(JournalFile *f) { printf("Disk usage: %s\n", format_bytes(bytes, sizeof(bytes), (off_t) st.st_blocks * 512ULL)); } +static int journal_file_warn_btrfs(JournalFile *f) { + unsigned attrs; + int r; + + assert(f); + + /* Before we write anything, check if the COW logic is turned + * off on btrfs. Given our write pattern that is quite + * unfriendly to COW file systems this should greatly improve + * performance on COW file systems, such as btrfs, at the + * expense of data integrity features (which shouldn't be too + * bad, given that we do our own checksumming). */ + + r = btrfs_is_filesystem(f->fd); + if (r < 0) + return log_warning_errno(r, "Failed to determine if journal is on btrfs: %m"); + if (!r) + return 0; + + r = read_attr_fd(f->fd, &attrs); + if (r < 0) + return log_warning_errno(r, "Failed to read file attributes: %m"); + + if (attrs & FS_NOCOW_FL) { + log_debug("Detected btrfs file system with copy-on-write disabled, all is good."); + return 0; + } + + log_notice("Creating journal file %s on a btrfs file system, and copy-on-write is enabled. " + "This is likely to slow down journal access substantially, please consider turning " + "off the copy-on-write file attribute on the journal directory, using chattr +C.", f->path); + + return 1; +} + int journal_file_open( const char *fname, int flags, @@ -2602,16 +2637,7 @@ int journal_file_open( if (f->last_stat.st_size == 0 && f->writable) { - /* Before we write anything, turn off COW logic. Given - * our write pattern that is quite unfriendly to COW - * file systems this should greatly improve - * performance on COW file systems, such as btrfs, at - * the expense of data integrity features (which - * shouldn't be too bad, given that we do our own - * checksumming). */ - r = chattr_fd(f->fd, FS_NOCOW_FL, FS_NOCOW_FL); - if (r < 0 && r != -ENOTTY) - log_warning_errno(r, "Failed to set file attributes: %m"); + (void) journal_file_warn_btrfs(f); /* Let's attach the creation time to the journal file, * so that the vacuuming code knows the age of this |