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MFV r302653: 6111 zfs send should ignore datasets created after the e…
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…nding snapshot

illumos/illumos-gate@4a20c93
illumos/illumos-gate@4a20c93
e636653

https://www.illumos.org/issues/6111
  If you create a zfs child folder, zfs send returns an error when a recursive
  incremental send is done between two snapshots made prior to the folder
  creation.
  The problem can be reproduced with the following steps.
  root@zfs:/# zfs create pool/test
  root@zfs:/# zfs snapshot pool/test@snap1
  root@zfs:/# zfs snapshot pool/test@snap2
  root@zfs:/# zfs create pool/test/child
  root@zfs:/# zfs send -R -I pool/test@snap1 pool/test@snap2 > /dev/null
  WARNING: could not send pool/test/child@snap2: does not exist
  WARNING: could not send pool/test/child@snap2: does not exist
  root@zfs:/# echo $?
  1
  root@zfs:/# zfs snapshot -r pool/test@snap3
  root@zfs:/# zfs send -R -I pool/test@snap1 pool/test@snap3 > /dev/null
  root@zfs:/# echo $?
  0
  root@zfs:/# zfs send -R -I pool/test@snap2 pool/test@snap3 > /dev/null
  root@zfs:/# echo $?
  0
  Since pool/test/child was created after snap2, zfs send should not expect snap2
  to be in pool/test/child when doing a recursive send. It should examine the
  compare the creation time of the snapshot and each child folder to decide if
  the folder will be sent. The next incremental send between snap2 and snap3
  would properly create the child folder and snap3 which first appears in the
  child folder.
  The problem is identical if '-i' is used instead of '-I'.

Reviewed by: Alex Aizman alex.aizman@nexenta.com
Reviewed by: Alek Pinchuk alek.pinchuk@nexenta.com
Reviewed by: Roman Strashkin roman.strashkin@nexenta.com
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Reviewed by: Paul Dagnelie <pcd@delphix.com>
Approved by: Garrett D'Amore <garrett@damore.org>
Author: Alex Deiter <alex.deiter@nexenta.com>
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@amotin
amotin committed Sep 1, 2016
1 parent df47b93 commit 7641d40
Showing 1 changed file with 108 additions and 6 deletions.
114 changes: 108 additions & 6 deletions cddl/contrib/opensolaris/lib/libzfs/common/libzfs_sendrecv.c
View file
Expand Up @@ -579,13 +579,30 @@ fsavl_create(nvlist_t *fss)
* Routines for dealing with the giant nvlist of fs-nvlists, etc.
*/
typedef struct send_data {
/*
* assigned inside every recursive call,
* restored from *_save on return:
*
* guid of fromsnap snapshot in parent dataset
* txg of fromsnap snapshot in current dataset
* txg of tosnap snapshot in current dataset
*/

uint64_t parent_fromsnap_guid;
uint64_t fromsnap_txg;
uint64_t tosnap_txg;

/* the nvlists get accumulated during depth-first traversal */
nvlist_t *parent_snaps;
nvlist_t *fss;
nvlist_t *snapprops;

/* send-receive configuration, does not change during traversal */
const char *fsname;
const char *fromsnap;
const char *tosnap;
boolean_t recursive;
boolean_t verbose;

/*
* The header nvlist is of the following format:
Expand Down Expand Up @@ -618,11 +635,23 @@ send_iterate_snap(zfs_handle_t *zhp, void *arg)
{
send_data_t *sd = arg;
uint64_t guid = zhp->zfs_dmustats.dds_guid;
uint64_t txg = zhp->zfs_dmustats.dds_creation_txg;
char *snapname;
nvlist_t *nv;

snapname = strrchr(zhp->zfs_name, '@')+1;

if (sd->tosnap_txg != 0 && txg > sd->tosnap_txg) {
if (sd->verbose) {
(void) fprintf(stderr, dgettext(TEXT_DOMAIN,
"skipping snapshot %s because it was created "
"after the destination snapshot (%s)\n"),
zhp->zfs_name, sd->tosnap);
}
zfs_close(zhp);
return (0);
}

VERIFY(0 == nvlist_add_uint64(sd->parent_snaps, snapname, guid));
/*
* NB: if there is no fromsnap here (it's a newly created fs in
Expand Down Expand Up @@ -715,6 +744,31 @@ send_iterate_prop(zfs_handle_t *zhp, nvlist_t *nv)
}
}

/*
* returns snapshot creation txg
* and returns 0 if the snapshot does not exist
*/
static uint64_t
get_snap_txg(libzfs_handle_t *hdl, const char *fs, const char *snap)
{
char name[ZFS_MAXNAMELEN];
uint64_t txg = 0;

if (fs == NULL || fs[0] == '\0' || snap == NULL || snap[0] == '\0')
return (txg);

(void) snprintf(name, sizeof (name), "%s@%s", fs, snap);
if (zfs_dataset_exists(hdl, name, ZFS_TYPE_SNAPSHOT)) {
zfs_handle_t *zhp = zfs_open(hdl, name, ZFS_TYPE_SNAPSHOT);
if (zhp != NULL) {
txg = zfs_prop_get_int(zhp, ZFS_PROP_CREATETXG);
zfs_close(zhp);
}
}

return (txg);
}

/*
* recursively generate nvlists describing datasets. See comment
* for the data structure send_data_t above for description of contents
Expand All @@ -727,9 +781,48 @@ send_iterate_fs(zfs_handle_t *zhp, void *arg)
nvlist_t *nvfs, *nv;
int rv = 0;
uint64_t parent_fromsnap_guid_save = sd->parent_fromsnap_guid;
uint64_t fromsnap_txg_save = sd->fromsnap_txg;
uint64_t tosnap_txg_save = sd->tosnap_txg;
uint64_t txg = zhp->zfs_dmustats.dds_creation_txg;
uint64_t guid = zhp->zfs_dmustats.dds_guid;
uint64_t fromsnap_txg, tosnap_txg;
char guidstring[64];

fromsnap_txg = get_snap_txg(zhp->zfs_hdl, zhp->zfs_name, sd->fromsnap);
if (fromsnap_txg != 0)
sd->fromsnap_txg = fromsnap_txg;

tosnap_txg = get_snap_txg(zhp->zfs_hdl, zhp->zfs_name, sd->tosnap);
if (tosnap_txg != 0)
sd->tosnap_txg = tosnap_txg;

/*
* on the send side, if the current dataset does not have tosnap,
* perform two additional checks:
*
* - skip sending the current dataset if it was created later than
* the parent tosnap
* - return error if the current dataset was created earlier than
* the parent tosnap
*/
if (sd->tosnap != NULL && tosnap_txg == 0) {
if (sd->tosnap_txg != 0 && txg > sd->tosnap_txg) {
if (sd->verbose) {
(void) fprintf(stderr, dgettext(TEXT_DOMAIN,
"skipping dataset %s: snapshot %s does "
"not exist\n"), zhp->zfs_name, sd->tosnap);
}
} else {
(void) fprintf(stderr, dgettext(TEXT_DOMAIN,
"cannot send %s@%s%s: snapshot %s@%s does not "
"exist\n"), sd->fsname, sd->tosnap, sd->recursive ?
dgettext(TEXT_DOMAIN, " recursively") : "",
zhp->zfs_name, sd->tosnap);
rv = -1;
}
goto out;
}

VERIFY(0 == nvlist_alloc(&nvfs, NV_UNIQUE_NAME, 0));
VERIFY(0 == nvlist_add_string(nvfs, "name", zhp->zfs_name));
VERIFY(0 == nvlist_add_uint64(nvfs, "parentfromsnap",
Expand All @@ -738,8 +831,10 @@ send_iterate_fs(zfs_handle_t *zhp, void *arg)
if (zhp->zfs_dmustats.dds_origin[0]) {
zfs_handle_t *origin = zfs_open(zhp->zfs_hdl,
zhp->zfs_dmustats.dds_origin, ZFS_TYPE_SNAPSHOT);
if (origin == NULL)
return (-1);
if (origin == NULL) {
rv = -1;
goto out;
}
VERIFY(0 == nvlist_add_uint64(nvfs, "origin",
origin->zfs_dmustats.dds_guid));
}
Expand Down Expand Up @@ -770,15 +865,19 @@ send_iterate_fs(zfs_handle_t *zhp, void *arg)
if (sd->recursive)
rv = zfs_iter_filesystems(zhp, send_iterate_fs, sd);

out:
sd->parent_fromsnap_guid = parent_fromsnap_guid_save;
sd->fromsnap_txg = fromsnap_txg_save;
sd->tosnap_txg = tosnap_txg_save;

zfs_close(zhp);
return (rv);
}

static int
gather_nvlist(libzfs_handle_t *hdl, const char *fsname, const char *fromsnap,
const char *tosnap, boolean_t recursive, nvlist_t **nvlp, avl_tree_t **avlp)
const char *tosnap, boolean_t recursive, boolean_t verbose,
nvlist_t **nvlp, avl_tree_t **avlp)
{
zfs_handle_t *zhp;
send_data_t sd = { 0 };
Expand All @@ -789,9 +888,11 @@ gather_nvlist(libzfs_handle_t *hdl, const char *fsname, const char *fromsnap,
return (EZFS_BADTYPE);

VERIFY(0 == nvlist_alloc(&sd.fss, NV_UNIQUE_NAME, 0));
sd.fsname = fsname;
sd.fromsnap = fromsnap;
sd.tosnap = tosnap;
sd.recursive = recursive;
sd.verbose = verbose;

if ((error = send_iterate_fs(zhp, &sd)) != 0) {
nvlist_free(sd.fss);
Expand Down Expand Up @@ -1699,7 +1800,8 @@ zfs_send(zfs_handle_t *zhp, const char *fromsnap, const char *tosnap,
}

err = gather_nvlist(zhp->zfs_hdl, zhp->zfs_name,
fromsnap, tosnap, flags->replicate, &fss, &fsavl);
fromsnap, tosnap, flags->replicate, flags->verbose,
&fss, &fsavl);
if (err)
goto err_out;
VERIFY(0 == nvlist_add_nvlist(hdrnv, "fss", fss));
Expand Down Expand Up @@ -2315,7 +2417,7 @@ recv_incremental_replication(libzfs_handle_t *hdl, const char *tofs,
VERIFY(0 == nvlist_alloc(&deleted, NV_UNIQUE_NAME, 0));

if ((error = gather_nvlist(hdl, tofs, fromsnap, NULL,
recursive, &local_nv, &local_avl)) != 0)
recursive, B_FALSE, &local_nv, &local_avl)) != 0)
return (error);

/*
Expand Down Expand Up @@ -3379,7 +3481,7 @@ zfs_receive_one(libzfs_handle_t *hdl, int infd, const char *tosnap,
*/
*cp = '\0';
if (gather_nvlist(hdl, zc.zc_value, NULL, NULL, B_FALSE,
&local_nv, &local_avl) == 0) {
B_FALSE, &local_nv, &local_avl) == 0) {
*cp = '@';
fs = fsavl_find(local_avl, drrb->drr_toguid, NULL);
fsavl_destroy(local_avl);
Expand Down

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