From patchwork Fri Oct 25 06:34:16 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Darrick J. Wong" X-Patchwork-Id: 13850095 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 6FC921CF96 for ; Fri, 25 Oct 2024 06:34:17 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1729838057; cv=none; b=XdJLblLHIDh/hFJB+Bbgqoyv+tPbmGshitYFo1wyyJmtXJ0qiOikmT0W2vZFvb3l/M8v07cZeI9SMstTtpbq6PLDaTnCi6J+9cy9hQdkZ6JoYRZXymN7leOeH+sUghcvSz0zVQgihWaoo2EupcVv9uPfUtPeF/IgTr4Gca9qqao= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1729838057; c=relaxed/simple; bh=VMlnZuHjBiD6M2h6NQalcon/08D20hDwYhTgose8m2A=; h=Date:Subject:From:To:Cc:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=if5xaADnK7BOq6i/gyp9qj7DQ7XsXBlG9Wf6LhrsFMILIWmd/B1YdCNFcOnZeBaZkdxHIaPMQXOIRlVeITIddNySlMk1dNXy/0cZlvvBvq7g725jq91zUZSaskQhkAu5pXsaK5P8PXh0WbkF+PZlMs3SxX4kDLB2W+DCbMFU/FY= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=Jd5HdjP4; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="Jd5HdjP4" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 3CE2CC4CEC3; Fri, 25 Oct 2024 06:34:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1729838057; bh=VMlnZuHjBiD6M2h6NQalcon/08D20hDwYhTgose8m2A=; h=Date:Subject:From:To:Cc:In-Reply-To:References:From; b=Jd5HdjP45xgn8T71T/R4jGhaIff/s9INwDaAPeLY9jPbMzTbR9six3VSj3tOpI6qv 7y2IfhX0YstcmIouQ6RetYsXgAM/7VXMLi9b6e6eXKNoeDchadXCR7As+xLCVJweKI B3BFEMTGTg8uY3DgypPwenPh8HKbNpdIr8gtQhcF0/XSWJt8SMaKJ7zONUDnNFM2QE 6kzzC/TFK1qm13tDvHxXUCmkQkFlXxAxG5IU8A/qFSsERcdExeF01RHrxC7bNa6e9s GwGEtxHEc8IwHyIcXE752Ewc5s4mCxOpZNsE/ePI0a3J2C3xTWNbCJNw4ygKrFgqkv l+8OiqY2Q+GkQ== Date: Thu, 24 Oct 2024 23:34:16 -0700 Subject: [PATCH 7/7] xfs_io: add atomic file update commands to exercise file commit range From: "Darrick J. Wong" To: cem@kernel.org, aalbersh@kernel.org, djwong@kernel.org Cc: linux-xfs@vger.kernel.org, hch@lst.de Message-ID: <172983773435.3040944.11571503838591968979.stgit@frogsfrogsfrogs> In-Reply-To: <172983773323.3040944.5615240418900510348.stgit@frogsfrogsfrogs> References: <172983773323.3040944.5615240418900510348.stgit@frogsfrogsfrogs> Precedence: bulk X-Mailing-List: linux-xfs@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 From: Darrick J. Wong Add three commands to xfs_io so that we can exercise atomic file updates as provided by reflink and the start-commit / commit-range functionality. Signed-off-by: Darrick J. Wong --- io/exchrange.c | 364 +++++++++++++++++++++++++++++++++++++++++++++++++++++ io/io.h | 4 + io/open.c | 27 +++- man/man8/xfs_io.8 | 32 +++++ 4 files changed, 421 insertions(+), 6 deletions(-) diff --git a/io/exchrange.c b/io/exchrange.c index 0a3750f1eb2607..707d78d8e624fe 100644 --- a/io/exchrange.c +++ b/io/exchrange.c @@ -164,6 +164,358 @@ static struct cmdinfo exchangerange_cmd = { .help = exchangerange_help, }; +/* Atomic file updates commands */ + +struct update_info { + /* File that we're updating. */ + int fd; + + /* ioctl data to commit the changes */ + struct xfs_commit_range xcr; + + /* Name of the file we're updating. */ + char *old_fname; + + /* fd we're using to stage the updates. */ + int temp_fd; +}; + +enum finish_how { + FINISH_ABORT, + FINISH_COMMIT, + FINISH_CHECK +}; + +static struct update_info *updates; +static unsigned int nr_updates; + +static void +startupdate_help(void) +{ + printf(_( +"\n" +" Prepare for an atomic file update, if supported by the filesystem.\n" +" A temporary file will be opened for writing and inserted into the file\n" +" table. The current file will be changed to this temporary file. Neither\n" +" file can be closed for the duration of the update.\n" +"\n" +" -e -- Start with an empty file\n" +"\n")); +} + +static int +startupdate_f( + int argc, + char *argv[]) +{ + struct fsxattr attr; + struct xfs_fsop_geom fsgeom; + struct fs_path fspath; + struct stat stat; + struct update_info *p; + char *fname; + char *path = NULL, *d; + size_t fname_len; + int flags = IO_TMPFILE | IO_ATOMICUPDATE; + int temp_fd = -1; + bool clone_file = true; + int c; + int ret; + + while ((c = getopt(argc, argv, "e")) != -1) { + switch (c) { + case 'e': + clone_file = false; + break; + default: + startupdate_help(); + return 0; + } + } + if (optind != argc) { + startupdate_help(); + return 0; + } + + /* Allocate a new slot. */ + p = realloc(updates, (++nr_updates) * sizeof(*p)); + if (!p) { + perror("startupdate realloc"); + goto fail; + } + updates = p; + + /* Fill out the update information so that we can commit later. */ + p = &updates[nr_updates - 1]; + memset(p, 0, sizeof(*p)); + + ret = fstat(file->fd, &stat); + if (ret) { + perror(file->name); + goto fail; + } + + /* Is the current file realtime? If so, the temp file must match. */ + ret = ioctl(file->fd, FS_IOC_FSGETXATTR, &attr); + if (ret == 0 && attr.fsx_xflags & FS_XFLAG_REALTIME) + flags |= IO_REALTIME; + + /* Compute path to the directory that the current file is in. */ + path = strdup(file->name); + d = strrchr(path, '/'); + if (!d) { + fprintf(stderr, _("%s: cannot compute dirname?"), path); + goto fail; + } + *d = 0; + + /* Open a temporary file to stage the new contents. */ + temp_fd = openfile(path, &fsgeom, flags, 0600, &fspath); + if (temp_fd < 0) { + perror(path); + goto fail; + } + + /* + * Snapshot the original file metadata in anticipation of the later + * file mapping exchange request. + */ + ret = xfrog_commitrange_prep(&p->xcr, file->fd, 0, temp_fd, 0, + stat.st_size); + if (ret) { + perror("update prep"); + goto fail; + } + + /* Clone all the data from the original file into the temporary file. */ + if (clone_file) { + ret = ioctl(temp_fd, XFS_IOC_CLONE, file->fd); + if (ret) { + perror(path); + goto fail; + } + } + + /* Prepare a new path string for the duration of the update. */ +#define FILEUPDATE_STR " (fileupdate)" + fname_len = strlen(file->name) + strlen(FILEUPDATE_STR); + fname = malloc(fname_len + 1); + if (!fname) { + perror("new path"); + goto fail; + } + snprintf(fname, fname_len + 1, "%s%s", file->name, FILEUPDATE_STR); + + /* + * Install the temporary file into the same slot of the file table as + * the original file. Ensure that the original file cannot be closed. + */ + file->flags |= IO_ATOMICUPDATE; + p->old_fname = file->name; + file->name = fname; + p->fd = file->fd; + p->temp_fd = file->fd = temp_fd; + + free(path); + return 0; +fail: + if (temp_fd >= 0) + close(temp_fd); + free(path); + nr_updates--; + exitcode = 1; + return 1; +} + +static long long +finish_update( + enum finish_how how, + uint64_t flags, + long long *offset) +{ + struct update_info *p; + long long committed_bytes = 0; + size_t length; + unsigned int i; + unsigned int upd_offset; + int temp_fd; + int ret; + + /* Find our update descriptor. */ + for (i = 0, p = updates; i < nr_updates; i++, p++) { + if (p->temp_fd == file->fd) + break; + } + + if (i == nr_updates) { + fprintf(stderr, + _("Current file is not the staging file for an atomic update.\n")); + exitcode = 1; + return -1; + } + + /* + * Commit our changes, if desired. If the mapping exchange fails, we + * stop processing immediately so that we can run more xfs_io commands. + */ + switch (how) { + case FINISH_CHECK: + flags |= XFS_EXCHANGE_RANGE_DRY_RUN; + fallthrough; + case FINISH_COMMIT: + ret = xfrog_commitrange(p->fd, &p->xcr, flags); + if (ret) { + xfrog_perror(ret, _("committing update")); + exitcode = 1; + return -1; + } + printf(_("Committed updates to '%s'.\n"), p->old_fname); + *offset = p->xcr.file2_offset; + committed_bytes = p->xcr.length; + break; + case FINISH_ABORT: + printf(_("Cancelled updates to '%s'.\n"), p->old_fname); + break; + } + + /* + * Reset the filetable to point to the original file, and close the + * temporary file. + */ + free(file->name); + file->name = p->old_fname; + file->flags &= ~IO_ATOMICUPDATE; + temp_fd = file->fd; + file->fd = p->fd; + ret = close(temp_fd); + if (ret) + perror(_("closing temporary file")); + + /* Remove the atomic update context, shifting things down. */ + upd_offset = p - updates; + length = nr_updates * sizeof(struct update_info); + length -= (upd_offset + 1) * sizeof(struct update_info); + if (length) + memmove(p, p + 1, length); + + nr_updates--; + return committed_bytes; +} + +static void +cancelupdate_help(void) +{ + printf(_( +"\n" +" Cancels an atomic file update. The temporary file will be closed, and the\n" +" current file set back to the original file.\n" +"\n")); +} + +static int +cancelupdate_f( + int argc, + char *argv[]) +{ + return finish_update(FINISH_ABORT, 0, NULL); +} + +static void +commitupdate_help(void) +{ + printf(_( +"\n" +" Commits an atomic file update. File contents written to the temporary file\n" +" will be exchanged atomically with the corresponding range in the original\n" +" file. The temporary file will be closed, and the current file set back to\n" +" the original file.\n" +"\n" +" -C -- Print timing information in a condensed format.\n" +" -h -- Only exchange written ranges in the temporary file.\n" +" -k -- Exchange to end of file, ignore any length previously set.\n" +" -n -- Check parameters but do not change anything.\n" +" -q -- Do not print timing information at all.\n")); +} + +static int +commitupdate_f( + int argc, + char *argv[]) +{ + struct timeval t1, t2; + enum finish_how how = FINISH_COMMIT; + uint64_t flags = XFS_EXCHANGE_RANGE_TO_EOF; + long long offset, len; + int condensed = 0, quiet_flag = 0; + int c; + + while ((c = getopt(argc, argv, "Chknq")) != -1) { + switch (c) { + case 'C': + condensed = 1; + break; + case 'h': + flags |= XFS_EXCHANGE_RANGE_FILE1_WRITTEN; + break; + case 'k': + flags &= ~XFS_EXCHANGE_RANGE_TO_EOF; + break; + case 'n': + how = FINISH_CHECK; + break; + case 'q': + quiet_flag = 1; + break; + default: + commitupdate_help(); + return 0; + } + } + if (optind != argc) { + commitupdate_help(); + return 0; + } + + gettimeofday(&t1, NULL); + len = finish_update(how, flags, &offset); + if (len < 0) + return 1; + if (quiet_flag) + return 0; + + gettimeofday(&t2, NULL); + t2 = tsub(t2, t1); + report_io_times("commitupdate", &t2, offset, len, len, 1, condensed); + return 0; +} + +static struct cmdinfo startupdate_cmd = { + .name = "startupdate", + .cfunc = startupdate_f, + .argmin = 0, + .argmax = -1, + .flags = CMD_FLAG_ONESHOT | CMD_NOMAP_OK, + .help = startupdate_help, +}; + +static struct cmdinfo cancelupdate_cmd = { + .name = "cancelupdate", + .cfunc = cancelupdate_f, + .argmin = 0, + .argmax = 0, + .flags = CMD_FLAG_ONESHOT | CMD_NOMAP_OK, + .help = cancelupdate_help, +}; + +static struct cmdinfo commitupdate_cmd = { + .name = "commitupdate", + .cfunc = commitupdate_f, + .argmin = 0, + .argmax = -1, + .flags = CMD_FLAG_ONESHOT | CMD_NOMAP_OK, + .help = commitupdate_help, +}; + void exchangerange_init(void) { @@ -171,4 +523,16 @@ exchangerange_init(void) exchangerange_cmd.oneline = _("Exchange contents between files."); add_command(&exchangerange_cmd); + + startupdate_cmd.oneline = _("start an atomic update of a file"); + startupdate_cmd.args = _("[-e]"); + + cancelupdate_cmd.oneline = _("cancel an atomic update"); + + commitupdate_cmd.oneline = _("commit a file update atomically"); + commitupdate_cmd.args = _("[-C] [-h] [-n] [-q]"); + + add_command(&startupdate_cmd); + add_command(&cancelupdate_cmd); + add_command(&commitupdate_cmd); } diff --git a/io/io.h b/io/io.h index 8c5e59100c5cbd..4daedac06419ae 100644 --- a/io/io.h +++ b/io/io.h @@ -31,6 +31,9 @@ #define IO_PATH (1<<10) #define IO_NOFOLLOW (1<<11) +/* undergoing atomic update, do not close */ +#define IO_ATOMICUPDATE (1<<12) + /* * Regular file I/O control */ @@ -74,6 +77,7 @@ extern int openfile(char *, struct xfs_fsop_geom *, int, mode_t, struct fs_path *); extern int addfile(char *, int , struct xfs_fsop_geom *, int, struct fs_path *); +extern int closefile(void); extern void printxattr(uint, int, int, const char *, int, int); extern unsigned int recurse_all; diff --git a/io/open.c b/io/open.c index 15850b5557bc5b..a30dd89a1fd56c 100644 --- a/io/open.c +++ b/io/open.c @@ -338,14 +338,19 @@ open_f( return 0; } -static int -close_f( - int argc, - char **argv) +int +closefile(void) { size_t length; unsigned int offset; + if (file->flags & IO_ATOMICUPDATE) { + fprintf(stderr, + _("%s: atomic update in progress, cannot close.\n"), + file->name); + exitcode = 1; + return 0; + } if (close(file->fd) < 0) { perror("close"); exitcode = 1; @@ -371,7 +376,19 @@ close_f( free(filetable); file = filetable = NULL; } - filelist_f(); + return 0; +} + +static int +close_f( + int argc, + char **argv) +{ + int ret; + + ret = closefile(); + if (!ret) + filelist_f(); return 0; } diff --git a/man/man8/xfs_io.8 b/man/man8/xfs_io.8 index 49d4057bb069ed..eb2201fca74380 100644 --- a/man/man8/xfs_io.8 +++ b/man/man8/xfs_io.8 @@ -1058,7 +1058,37 @@ .SH FILE I/O COMMANDS nsec is the nanoseconds since the sec. This value needs to be in the range 0-999999999 with UTIME_NOW and UTIME_OMIT being exceptions. Each (sec, nsec) pair constitutes a single timestamp value. - +.TP +.BI "startupdate [ " -e ] +Create a temporary clone of a file in which to stage file updates. +The +.B \-e +option creates an empty staging file. +.TP +.B cancelupdate +Abandon changes from a update staging file. +.TP +.BI "commitupdate [" OPTIONS ] +Commit changes from a update staging file to the real file. +.RS 1.0i +.PD 0 +.TP 0.4i +.B \-C +Print timing information in a condensed format. +.TP 0.4i +.B \-h +Only swap ranges in the update staging file that were actually written. +.TP 0.4i +.B \-k +Do not change file size. +.TP 0.4i +.B \-n +Check parameters without changing anything. +.TP 0.4i +.B \-q +Do not print timing information at all. +.PD +.RE .SH MEMORY MAPPED I/O COMMANDS .TP