From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from relay.sgi.com (relay1.corp.sgi.com [137.38.102.111]) by oss.sgi.com (Postfix) with ESMTP id BD9757F4E for ; Mon, 23 Mar 2015 15:00:15 -0500 (CDT) Received: from cuda.sgi.com (cuda3.sgi.com [192.48.176.15]) by relay1.corp.sgi.com (Postfix) with ESMTP id 898278F8068 for ; Mon, 23 Mar 2015 13:00:15 -0700 (PDT) Received: from sandeen.net (sandeen.net [63.231.237.45]) by cuda.sgi.com with ESMTP id SfDBcDnwvZDTgOaa for ; Mon, 23 Mar 2015 13:00:13 -0700 (PDT) Message-ID: <551070CC.9040309@sandeen.net> Date: Mon, 23 Mar 2015 15:00:12 -0500 From: Eric Sandeen MIME-Version: 1.0 Subject: [PATCH 01/13 V2] xfs_db: Allow writes of corrupted data by optionally skipping write verifiers References: <1426624395-8258-1-git-send-email-sandeen@redhat.com> <1426624395-8258-2-git-send-email-sandeen@redhat.com> In-Reply-To: <1426624395-8258-2-git-send-email-sandeen@redhat.com> List-Id: XFS Filesystem from SGI List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: xfs-bounces@oss.sgi.com Sender: xfs-bounces@oss.sgi.com To: Eric Sandeen , xfs@oss.sgi.com Being able to write corrupt data is handy if we wish to test repair against specific types of corruptions. Add a "-c" option to the write command which allows this by removing the write verifier. Note that this also skips CRC updates; it's not currently possible to write invalid data with a valid CRC; CRC recalculation is intertwined with validation. Signed-off-by: Eric Sandeen --- V2: Fix whitespace, remove "if (argc)", and test for iocur_top->bp->b_ops before attempting to deref it. diff --git a/db/io.c b/db/io.c index 7f1b76a..c5898f1 100644 --- a/db/io.c +++ b/db/io.c @@ -457,6 +457,13 @@ write_cur_bbs(void) } void +xfs_dummy_verify( + struct xfs_buf *bp) +{ + return; +} + +void write_cur(void) { if (iocur_sp < 0) { diff --git a/db/io.h b/db/io.h index 71082e6..31d96b4 100644 --- a/db/io.h +++ b/db/io.h @@ -63,6 +63,7 @@ extern void set_cur(const struct typ *t, __int64_t d, int c, int ring_add, bbmap_t *bbmap); extern void ring_add(void); extern void set_iocur_type(const struct typ *t); +extern void xfs_dummy_verify(struct xfs_buf *bp); /* * returns -1 for unchecked, 0 for bad and 1 for good diff --git a/db/write.c b/db/write.c index a0f14f4..655b618 100644 --- a/db/write.c +++ b/db/write.c @@ -38,7 +38,7 @@ static int write_f(int argc, char **argv); static void write_help(void); static const cmdinfo_t write_cmd = - { "write", NULL, write_f, 0, -1, 0, N_("[field or value]..."), + { "write", NULL, write_f, 0, -1, 0, N_("[-c] [field or value]..."), N_("write value to disk"), write_help }; void @@ -79,6 +79,7 @@ write_help(void) " String mode: 'write \"This_is_a_filename\" - write null terminated string.\n" "\n" " In data mode type 'write' by itself for a list of specific commands.\n\n" +" Specifying the -c option will allow writes of invalid (corrupt) data.\n\n" )); } @@ -90,6 +91,10 @@ write_f( { pfunc_t pf; extern char *progname; + int c; + int corrupt = 0; /* Allow write of corrupt data; skip verification */ + struct xfs_buf_ops nowrite_ops; + const struct xfs_buf_ops *stashed_ops = NULL; if (x.isreadonly & LIBXFS_ISREADONLY) { dbprintf(_("%s started in read only mode, writing disabled\n"), @@ -109,12 +114,34 @@ write_f( return 0; } - /* move past the "write" command */ - argc--; - argv++; + while ((c = getopt(argc, argv, "c")) != EOF) { + switch (c) { + case 'c': + corrupt = 1; + break; + default: + dbprintf(_("bad option for write command\n")); + return 0; + } + } + + argc -= optind; + argv += optind; + + if (iocur_top->bp->b_ops && corrupt) { + /* Temporarily remove write verifier to write bad data */ + stashed_ops = iocur_top->bp->b_ops; + nowrite_ops.verify_read = stashed_ops->verify_read; + nowrite_ops.verify_write = xfs_dummy_verify; + iocur_top->bp->b_ops = &nowrite_ops; + dbprintf(_("Allowing write of corrupted data\n")); + } (*pf)(DB_WRITE, cur_typ->fields, argc, argv); + if (stashed_ops) + iocur_top->bp->b_ops = stashed_ops; + return 0; } diff --git a/man/man8/xfs_db.8 b/man/man8/xfs_db.8 index 4d8d4ff..d527230 100644 --- a/man/man8/xfs_db.8 +++ b/man/man8/xfs_db.8 @@ -711,7 +711,7 @@ and bits respectively, and their string equivalent reported (but no modifications are made). .TP -.BI "write [" "field value" "] ..." +.BI "write [\-c] [" "field value" "] ..." Write a value to disk. Specific fields can be set in structures (struct mode), or a block can be set to data values (data mode), @@ -729,6 +729,12 @@ contents of the block can be shifted or rotated left or right, or filled with a sequence, a constant value, or a random value. In this mode .B write with no arguments gives more information on the allowed commands. +.RS 1.0i +.TP 0.4i +.B \-c +Skip write verifiers and CRC recalculation; allows invalid data to be written +to disk. +.RE .SH TYPES This section gives the fields in each structure type and their meanings. Note that some types of block cover multiple actual structures, _______________________________________________ xfs mailing list xfs@oss.sgi.com http://oss.sgi.com/mailman/listinfo/xfs