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Fix out-of-order ZIL txtype lost on hardlinked files

We should only call zil_remove_async when an object is removed. However,
in current implementation, it is called whenever TX_REMOVE is called. In
the case of hardlinked file, every unlink will generate TX_REMOVE and
causing operations to be dropped even when the object is not removed.

We fix this by only calling zil_remove_async when the file is fully
unlinked.

Reviewed-by: George Wilson <gwilson@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Prakash Surya <prakash.surya@delphix.com>
Signed-off-by: Chunwei Chen <david.chen@nutanix.com>
Closes #8769
Closes #9061
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tuxoko authored and behlendorf committed Aug 14, 2019
1 parent 475ebd7 commit 8e556c5ebc7b66caf2cdcc561b6644f9f8437a6d
@@ -371,7 +371,7 @@ extern void zfs_log_create(zilog_t *zilog, dmu_tx_t *tx, uint64_t txtype,
extern int zfs_log_create_txtype(zil_create_t, vsecattr_t *vsecp,
vattr_t *vap);
extern void zfs_log_remove(zilog_t *zilog, dmu_tx_t *tx, uint64_t txtype,
znode_t *dzp, char *name, uint64_t foid);
znode_t *dzp, char *name, uint64_t foid, boolean_t unlinked);
#define ZFS_NO_OBJECT 0 /* no object id */
extern void zfs_log_link(zilog_t *zilog, dmu_tx_t *tx, uint64_t txtype,
znode_t *dzp, znode_t *zp, char *name);
@@ -380,12 +380,14 @@ zfs_log_create(zilog_t *zilog, dmu_tx_t *tx, uint64_t txtype,
zil_itx_assign(zilog, itx, tx);
}

void zil_remove_async(zilog_t *zilog, uint64_t oid);

/*
* Handles both TX_REMOVE and TX_RMDIR transactions.
*/
void
zfs_log_remove(zilog_t *zilog, dmu_tx_t *tx, uint64_t txtype,
znode_t *dzp, char *name, uint64_t foid)
znode_t *dzp, char *name, uint64_t foid, boolean_t unlinked)
{
itx_t *itx;
lr_remove_t *lr;
@@ -401,6 +403,17 @@ zfs_log_remove(zilog_t *zilog, dmu_tx_t *tx, uint64_t txtype,

itx->itx_oid = foid;

/*
* Object ids can be re-instantiated in the next txg so
* remove any async transactions to avoid future leaks.
* This can happen if a fsync occurs on the re-instantiated
* object for a WR_INDIRECT or WR_NEED_COPY write, which gets
* the new file data and flushes a write record for the old object.
*/
if (unlinked) {
ASSERT((txtype & ~TX_CI) == TX_REMOVE);
zil_remove_async(zilog, foid);
}
zil_itx_assign(zilog, itx, tx);
}

@@ -1886,7 +1886,7 @@ zfs_remove(struct inode *dip, char *name, cred_t *cr, int flags)
txtype = TX_REMOVE;
if (flags & FIGNORECASE)
txtype |= TX_CI;
zfs_log_remove(zilog, tx, txtype, dzp, name, obj);
zfs_log_remove(zilog, tx, txtype, dzp, name, obj, unlinked);

dmu_tx_commit(tx);
out:
@@ -2219,7 +2219,8 @@ zfs_rmdir(struct inode *dip, char *name, struct inode *cwd, cred_t *cr,
uint64_t txtype = TX_RMDIR;
if (flags & FIGNORECASE)
txtype |= TX_CI;
zfs_log_remove(zilog, tx, txtype, dzp, name, ZFS_NO_OBJECT);
zfs_log_remove(zilog, tx, txtype, dzp, name, ZFS_NO_OBJECT,
B_FALSE);
}

dmu_tx_commit(tx);
@@ -1875,7 +1875,7 @@ zil_aitx_compare(const void *x1, const void *x2)
/*
* Remove all async itx with the given oid.
*/
static void
void
zil_remove_async(zilog_t *zilog, uint64_t oid)
{
uint64_t otxg, txg;
@@ -1927,16 +1927,6 @@ zil_itx_assign(zilog_t *zilog, itx_t *itx, dmu_tx_t *tx)
itxg_t *itxg;
itxs_t *itxs, *clean = NULL;

/*
* Object ids can be re-instantiated in the next txg so
* remove any async transactions to avoid future leaks.
* This can happen if a fsync occurs on the re-instantiated
* object for a WR_INDIRECT or WR_NEED_COPY write, which gets
* the new file data and flushes a write record for the old object.
*/
if ((itx->itx_lr.lrc_txtype & ~TX_CI) == TX_REMOVE)
zil_remove_async(zilog, itx->itx_oid);

/*
* Ensure the data of a renamed file is committed before the rename.
*/
@@ -160,6 +160,14 @@ log_must attr -qs fileattr -V HelloWorld /$TESTPOOL/$TESTFS/xattr.file
log_must attr -qs tmpattr -V HelloWorld /$TESTPOOL/$TESTFS/xattr.file
log_must attr -qr tmpattr /$TESTPOOL/$TESTFS/xattr.file

# TX_WRITE, TX_LINK, TX_REMOVE
# Make sure TX_REMOVE won't affect TX_WRITE if file is not destroyed
log_must dd if=/dev/urandom of=/$TESTPOOL/$TESTFS/link_and_unlink bs=128k \
count=8
log_must ln /$TESTPOOL/$TESTFS/link_and_unlink \
/$TESTPOOL/$TESTFS/link_and_unlink.link
log_must rm /$TESTPOOL/$TESTFS/link_and_unlink.link

#
# 4. Copy TESTFS to temporary location (TESTDIR/copy)
#

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