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.
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 <sandeen@xxxxxxxxxx>
---
diff --git a/db/crc.c b/db/crc.c
index ad46c3f..861086a 100644
--- a/db/crc.c
+++ b/db/crc.c
@@ -58,13 +58,6 @@ crc_help(void)
}
-void
-xfs_dummy_verify(
- struct xfs_buf *bp)
-{
- return;
-}
-
static int
crc_f(
int argc,
diff --git a/db/crc.h b/db/crc.h
index 80ecec3..9f44615 100644
--- a/db/crc.h
+++ b/db/crc.h
@@ -20,4 +20,3 @@ struct field;
extern void crc_init(void);
extern void crc_struct(const field_t *fields, int argc, char **argv);
-extern void xfs_dummy_verify(struct xfs_buf *bp);
diff --git a/db/io.c b/db/io.c
index eb3daa1..2d18d56 100644
--- a/db/io.c
+++ b/db/io.c
@@ -458,6 +458,13 @@ write_cur_bbs(void)
}
void
+xfs_dummy_verify(
+ struct xfs_buf *bp)
+{
+ return;
+}
+
+void
write_cur(void)
{
int skip_crc = (iocur_top->bp->b_ops->verify_write == xfs_dummy_verify);
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..a01c25a 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 +91,9 @@ write_f(
{
pfunc_t pf;
extern char *progname;
+ int c;
+ int corrupt = 0; /* Allow write of corrupt data; skip verification */
+ 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 +113,36 @@ write_f(
return 0;
}
- /* move past the "write" command */
- argc--;
- argv++;
+ if (argc) 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 (corrupt) {
+ struct xfs_buf_ops nowrite_ops;
+
+ /* 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 0764832..46a1f39 100644
--- a/man/man8/xfs_db.8
+++ b/man/man8/xfs_db.8
@@ -728,7 +728,7 @@ 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),
@@ -746,6 +746,12 @@ 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,
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