int error = 0;
/* Holes, unwritten, and delalloc extents cannot be shared */
- if (!xfs_is_cow_inode(ip) || !xfs_bmap_is_real_extent(irec)) {
+ if (!xfs_is_cow_inode(ip) || !xfs_bmap_is_written_extent(irec)) {
*shared = false;
return 0;
}
* preallocations can leak into the range we are called upon, and we
* need to skip them.
*/
- if (!xfs_bmap_is_real_extent(&got)) {
+ if (!xfs_bmap_is_written_extent(&got)) {
*end_fsb = del.br_startoff;
goto out_cancel;
}
}
/*
- * Unmap a range of blocks from a file, then map other blocks into the hole.
- * The range to unmap is (destoff : destoff + srcioff + irec->br_blockcount).
- * The extent irec is mapped into dest at irec->br_startoff.
+ * Remap the given extent into the file. The dmap blockcount will be set to
+ * the number of blocks that were actually remapped.
*/
STATIC int
xfs_reflink_remap_extent(
struct xfs_inode *ip,
- struct xfs_bmbt_irec *irec,
- xfs_fileoff_t destoff,
+ struct xfs_bmbt_irec *dmap,
xfs_off_t new_isize)
{
+ struct xfs_bmbt_irec smap;
struct xfs_mount *mp = ip->i_mount;
- bool real_extent = xfs_bmap_is_real_extent(irec);
struct xfs_trans *tp;
- unsigned int resblks;
- struct xfs_bmbt_irec uirec;
- xfs_filblks_t rlen;
- xfs_filblks_t unmap_len;
xfs_off_t newlen;
+ int64_t qres, qdelta;
+ unsigned int resblks;
+ bool smap_real;
+ bool dmap_written = xfs_bmap_is_written_extent(dmap);
+ int nimaps;
int error;
- unmap_len = irec->br_startoff + irec->br_blockcount - destoff;
- trace_xfs_reflink_punch_range(ip, destoff, unmap_len);
-
- /* No reflinking if we're low on space */
- if (real_extent) {
- error = xfs_reflink_ag_has_free_space(mp,
- XFS_FSB_TO_AGNO(mp, irec->br_startblock));
- if (error)
- goto out;
- }
-
/* Start a rolling transaction to switch the mappings */
- resblks = XFS_EXTENTADD_SPACE_RES(ip->i_mount, XFS_DATA_FORK);
+ resblks = XFS_EXTENTADD_SPACE_RES(mp, XFS_DATA_FORK);
error = xfs_trans_alloc(mp, &M_RES(mp)->tr_write, resblks, 0, 0, &tp);
if (error)
goto out;
xfs_ilock(ip, XFS_ILOCK_EXCL);
xfs_trans_ijoin(tp, ip, 0);
- /* If we're not just clearing space, then do we have enough quota? */
- if (real_extent) {
- error = xfs_trans_reserve_quota_nblks(tp, ip,
- irec->br_blockcount, 0, XFS_QMOPT_RES_REGBLKS);
+ /*
+ * Read what's currently mapped in the destination file into smap.
+ * If smap isn't a hole, we will have to remove it before we can add
+ * dmap to the destination file.
+ */
+ nimaps = 1;
+ error = xfs_bmapi_read(ip, dmap->br_startoff, dmap->br_blockcount,
+ &smap, &nimaps, 0);
+ if (error)
+ goto out_cancel;
+ ASSERT(nimaps == 1 && smap.br_startoff == dmap->br_startoff);
+ smap_real = xfs_bmap_is_real_extent(&smap);
+
+ /*
+ * We can only remap as many blocks as the smaller of the two extent
+ * maps, because we can only remap one extent at a time.
+ */
+ dmap->br_blockcount = min(dmap->br_blockcount, smap.br_blockcount);
+ ASSERT(dmap->br_blockcount == smap.br_blockcount);
+
+ trace_xfs_reflink_remap_extent_dest(ip, &smap);
+
+ /*
+ * Two extents mapped to the same physical block must not have
+ * different states; that's filesystem corruption. Move on to the next
+ * extent if they're both holes or both the same physical extent.
+ */
+ if (dmap->br_startblock == smap.br_startblock) {
+ if (dmap->br_state != smap.br_state)
+ error = -EFSCORRUPTED;
+ goto out_cancel;
+ }
+
+ /* If both extents are unwritten, leave them alone. */
+ if (dmap->br_state == XFS_EXT_UNWRITTEN &&
+ smap.br_state == XFS_EXT_UNWRITTEN)
+ goto out_cancel;
+
+ /* No reflinking if the AG of the dest mapping is low on space. */
+ if (dmap_written) {
+ error = xfs_reflink_ag_has_free_space(mp,
+ XFS_FSB_TO_AGNO(mp, dmap->br_startblock));
if (error)
goto out_cancel;
}
- trace_xfs_reflink_remap(ip, irec->br_startoff,
- irec->br_blockcount, irec->br_startblock);
-
- /* Unmap the old blocks in the data fork. */
- rlen = unmap_len;
- while (rlen) {
- ASSERT(tp->t_firstblock == NULLFSBLOCK);
- error = __xfs_bunmapi(tp, ip, destoff, &rlen, 0, 1);
+ /*
+ * Compute quota reservation if we think the quota block counter for
+ * this file could increase.
+ *
+ * Adding a written extent to the extent map can cause a bmbt split,
+ * and removing a mapped extent from the extent can cause a bmbt split.
+ * The two operations cannot both cause a split since they operate on
+ * the same index in the bmap btree, so we only need a reservation for
+ * one bmbt split if either thing is happening.
+ *
+ * If we are mapping a written extent into the file, we need to have
+ * enough quota block count reservation to handle the blocks in that
+ * extent. We log only the delta to the quota block counts, so if the
+ * extent we're unmapping also has blocks allocated to it, we don't
+ * need a quota reservation for the extent itself.
+ *
+ * Note that if we're replacing a delalloc reservation with a written
+ * extent, we have to take the full quota reservation because removing
+ * the delalloc reservation gives the block count back to the quota
+ * count. This is suboptimal, but the VFS flushed the dest range
+ * before we started. That should have removed all the delalloc
+ * reservations, but we code defensively.
+ */
+ qres = qdelta = 0;
+ if (smap_real || dmap_written)
+ qres = XFS_EXTENTADD_SPACE_RES(mp, XFS_DATA_FORK);
+ if (!smap_real && dmap_written)
+ qres += dmap->br_blockcount;
+ if (qres > 0) {
+ error = xfs_trans_reserve_quota_nblks(tp, ip, qres, 0,
+ XFS_QMOPT_RES_REGBLKS);
if (error)
goto out_cancel;
+ }
+ if (smap_real) {
/*
- * Trim the extent to whatever got unmapped.
- * Remember, bunmapi works backwards.
+ * If the extent we're unmapping is backed by storage (written
+ * or not), unmap the extent and drop its refcount.
*/
- uirec.br_startblock = irec->br_startblock + rlen;
- uirec.br_startoff = irec->br_startoff + rlen;
- uirec.br_blockcount = unmap_len - rlen;
- uirec.br_state = irec->br_state;
- unmap_len = rlen;
-
- /* If this isn't a real mapping, we're done. */
- if (!real_extent || uirec.br_blockcount == 0)
- goto next_extent;
+ xfs_bmap_unmap_extent(tp, ip, &smap);
+ xfs_refcount_decrease_extent(tp, &smap);
+ qdelta -= smap.br_blockcount;
+ } else if (smap.br_startblock == DELAYSTARTBLOCK) {
+ xfs_filblks_t len = smap.br_blockcount;
- trace_xfs_reflink_remap(ip, uirec.br_startoff,
- uirec.br_blockcount, uirec.br_startblock);
-
- /* Update the refcount tree */
- xfs_refcount_increase_extent(tp, &uirec);
-
- /* Map the new blocks into the data fork. */
- xfs_bmap_map_extent(tp, ip, &uirec);
+ /*
+ * If the extent we're unmapping is a delalloc reservation,
+ * we can use the regular bunmapi function to release the
+ * incore state. Dropping the delalloc reservation takes care
+ * of the quota reservation for us.
+ */
+ error = __xfs_bunmapi(NULL, ip, smap.br_startoff, &len, 0, 1);
+ if (error)
+ goto out_cancel;
+ ASSERT(len == 0);
+ }
- /* Update quota accounting. */
- xfs_trans_mod_dquot_byino(tp, ip, XFS_TRANS_DQ_BCOUNT,
- uirec.br_blockcount);
+ /*
+ * If the extent we're sharing is backed by written storage, increase
+ * its refcount and map it into the file.
+ */
+ if (dmap_written) {
+ xfs_refcount_increase_extent(tp, dmap);
+ xfs_bmap_map_extent(tp, ip, dmap);
+ qdelta += dmap->br_blockcount;
+ }
- /* Update dest isize if needed. */
- newlen = XFS_FSB_TO_B(mp,
- uirec.br_startoff + uirec.br_blockcount);
- newlen = min_t(xfs_off_t, newlen, new_isize);
- if (newlen > i_size_read(VFS_I(ip))) {
- trace_xfs_reflink_update_inode_size(ip, newlen);
- i_size_write(VFS_I(ip), newlen);
- ip->i_d.di_size = newlen;
- xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
- }
+ xfs_trans_mod_dquot_byino(tp, ip, XFS_TRANS_DQ_BCOUNT, qdelta);
-next_extent:
- /* Process all the deferred stuff. */
- error = xfs_defer_finish(&tp);
- if (error)
- goto out_cancel;
+ /* Update dest isize if needed. */
+ newlen = XFS_FSB_TO_B(mp, dmap->br_startoff + dmap->br_blockcount);
+ newlen = min_t(xfs_off_t, newlen, new_isize);
+ if (newlen > i_size_read(VFS_I(ip))) {
+ trace_xfs_reflink_update_inode_size(ip, newlen);
+ i_size_write(VFS_I(ip), newlen);
+ ip->i_d.di_size = newlen;
+ xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
}
+ /* Commit everything and unlock. */
error = xfs_trans_commit(tp);
- xfs_iunlock(ip, XFS_ILOCK_EXCL);
- if (error)
- goto out;
- return 0;
+ goto out_unlock;
out_cancel:
xfs_trans_cancel(tp);
+out_unlock:
xfs_iunlock(ip, XFS_ILOCK_EXCL);
out:
- trace_xfs_reflink_remap_extent_error(ip, error, _RET_IP_);
+ if (error)
+ trace_xfs_reflink_remap_extent_error(ip, error, _RET_IP_);
return error;
}
-/*
- * Iteratively remap one file's extents (and holes) to another's.
- */
+/* Remap a range of one file to the other. */
int
xfs_reflink_remap_blocks(
struct xfs_inode *src,
loff_t *remapped)
{
struct xfs_bmbt_irec imap;
- xfs_fileoff_t srcoff;
- xfs_fileoff_t destoff;
+ struct xfs_mount *mp = src->i_mount;
+ xfs_fileoff_t srcoff = XFS_B_TO_FSBT(mp, pos_in);
+ xfs_fileoff_t destoff = XFS_B_TO_FSBT(mp, pos_out);
xfs_filblks_t len;
- xfs_filblks_t range_len;
xfs_filblks_t remapped_len = 0;
xfs_off_t new_isize = pos_out + remap_len;
int nimaps;
int error = 0;
- destoff = XFS_B_TO_FSBT(src->i_mount, pos_out);
- srcoff = XFS_B_TO_FSBT(src->i_mount, pos_in);
- len = XFS_B_TO_FSB(src->i_mount, remap_len);
+ len = min_t(xfs_filblks_t, XFS_B_TO_FSB(mp, remap_len),
+ XFS_MAX_FILEOFF);
- /* drange = (destoff, destoff + len); srange = (srcoff, srcoff + len) */
- while (len) {
- uint lock_mode;
+ trace_xfs_reflink_remap_blocks(src, srcoff, len, dest, destoff);
- trace_xfs_reflink_remap_blocks_loop(src, srcoff, len,
- dest, destoff);
+ while (len > 0) {
+ unsigned int lock_mode;
/* Read extent from the source file */
nimaps = 1;
xfs_iunlock(src, lock_mode);
if (error)
break;
- ASSERT(nimaps == 1);
-
- trace_xfs_reflink_remap_imap(src, srcoff, len, XFS_DATA_FORK,
- &imap);
+ /*
+ * The caller supposedly flushed all dirty pages in the source
+ * file range, which means that writeback should have allocated
+ * or deleted all delalloc reservations in that range. If we
+ * find one, that's a good sign that something is seriously
+ * wrong here.
+ */
+ ASSERT(nimaps == 1 && imap.br_startoff == srcoff);
+ if (imap.br_startblock == DELAYSTARTBLOCK) {
+ ASSERT(imap.br_startblock != DELAYSTARTBLOCK);
+ error = -EFSCORRUPTED;
+ break;
+ }
- /* Translate imap into the destination file. */
- range_len = imap.br_startoff + imap.br_blockcount - srcoff;
- imap.br_startoff += destoff - srcoff;
+ trace_xfs_reflink_remap_extent_src(src, &imap);
- /* Clear dest from destoff to the end of imap and map it in. */
- error = xfs_reflink_remap_extent(dest, &imap, destoff,
- new_isize);
+ /* Remap into the destination file at the given offset. */
+ imap.br_startoff = destoff;
+ error = xfs_reflink_remap_extent(dest, &imap, new_isize);
if (error)
break;
}
/* Advance drange/srange */
- srcoff += range_len;
- destoff += range_len;
- len -= range_len;
- remapped_len += range_len;
+ srcoff += imap.br_blockcount;
+ destoff += imap.br_blockcount;
+ len -= imap.br_blockcount;
+ remapped_len += imap.br_blockcount;
}
if (error)
return error;
}
-/*
- * Grab the exclusive iolock for a data copy from src to dest, making sure to
- * abide vfs locking order (lowest pointer value goes first) and breaking the
- * layout leases before proceeding. The loop is needed because we cannot call
- * the blocking break_layout() with the iolocks held, and therefore have to
- * back out both locks.
- */
-static int
-xfs_iolock_two_inodes_and_break_layout(
- struct inode *src,
- struct inode *dest)
-{
- int error;
-
- if (src > dest)
- swap(src, dest);
-
-retry:
- /* Wait to break both inodes' layouts before we start locking. */
- error = break_layout(src, true);
- if (error)
- return error;
- if (src != dest) {
- error = break_layout(dest, true);
- if (error)
- return error;
- }
-
- /* Lock one inode and make sure nobody got in and leased it. */
- inode_lock(src);
- error = break_layout(src, false);
- if (error) {
- inode_unlock(src);
- if (error == -EWOULDBLOCK)
- goto retry;
- return error;
- }
-
- if (src == dest)
- return 0;
-
- /* Lock the other inode and make sure nobody got in and leased it. */
- inode_lock_nested(dest, I_MUTEX_NONDIR2);
- error = break_layout(dest, false);
- if (error) {
- inode_unlock(src);
- inode_unlock(dest);
- if (error == -EWOULDBLOCK)
- goto retry;
- return error;
- }
-
- return 0;
-}
-
-/* Unlock both inodes after they've been prepped for a range clone. */
-void
-xfs_reflink_remap_unlock(
- struct file *file_in,
- struct file *file_out)
-{
- struct inode *inode_in = file_inode(file_in);
- struct xfs_inode *src = XFS_I(inode_in);
- struct inode *inode_out = file_inode(file_out);
- struct xfs_inode *dest = XFS_I(inode_out);
- bool same_inode = (inode_in == inode_out);
-
- xfs_iunlock(dest, XFS_MMAPLOCK_EXCL);
- if (!same_inode)
- xfs_iunlock(src, XFS_MMAPLOCK_EXCL);
- inode_unlock(inode_out);
- if (!same_inode)
- inode_unlock(inode_in);
-}
-
/*
* If we're reflinking to a point past the destination file's EOF, we must
* zero any speculative post-EOF preallocations that sit between the old EOF
struct xfs_inode *src = XFS_I(inode_in);
struct inode *inode_out = file_inode(file_out);
struct xfs_inode *dest = XFS_I(inode_out);
- bool same_inode = (inode_in == inode_out);
- ssize_t ret;
+ int ret;
/* Lock both files against IO */
- ret = xfs_iolock_two_inodes_and_break_layout(inode_in, inode_out);
+ ret = xfs_ilock2_io_mmap(src, dest);
if (ret)
return ret;
- if (same_inode)
- xfs_ilock(src, XFS_MMAPLOCK_EXCL);
- else
- xfs_lock_two_inodes(src, XFS_MMAPLOCK_EXCL, dest,
- XFS_MMAPLOCK_EXCL);
/* Check file eligibility and prepare for block sharing. */
ret = -EINVAL;
ret = generic_remap_file_range_prep(file_in, pos_in, file_out, pos_out,
len, remap_flags);
- if (ret < 0 || *len == 0)
+ if (ret || *len == 0)
goto out_unlock;
/* Attach dquots to dest inode before changing block map */
if (ret)
goto out_unlock;
- return 1;
+ return 0;
out_unlock:
- xfs_reflink_remap_unlock(file_in, file_out);
+ xfs_iunlock2_io_mmap(src, dest);
return ret;
}
projects / linux-2.6-microblaze.git / blobdiff