diff --git a/mercurial/revlog.py b/mercurial/revlog.py
--- a/mercurial/revlog.py
+++ b/mercurial/revlog.py
@@ -2026,7 +2026,15 @@ class revlog:
 
         The file will only exist if a splitting operation is in progress, but
         it is always expected at the same location."""
-        return self.radix + b'.i.s'
+        parts = os.path.split(self.radix)
+        if len(parts) > 1:
+            # adds a '-s' prefix to the ``data/` or `meta/` base
+            head = parts[0] + b'-s'
+            return os.path.join(head, *parts[1:])
+        else:
+            # the revlog is stored at the root of the store (changelog or
+            # manifest), no risk of collision.
+            return self.radix + b'.i.s'
 
     def _enforceinlinesize(self, tr, side_write=True):
         """Check if the revlog is too big for inline and convert if so.
diff --git a/tests/test-transaction-rollback-on-revlog-split.t b/tests/test-transaction-rollback-on-revlog-split.t
--- a/tests/test-transaction-rollback-on-revlog-split.t
+++ b/tests/test-transaction-rollback-on-revlog-split.t
@@ -84,6 +84,8 @@ setup a repository for tests
   > Directory_With,Special%Char/Complex_File.babar
   > foo/bar/babar_celeste/foo
   > 1234567890/1234567890/1234567890/1234567890/1234567890/1234567890/1234567890/1234567890/1234567890/1234567890/f
+  > some_dir/sub_dir/foo_bar
+  > some_dir/sub_dir/foo_bar.i.s/tutu
   > "
   $ for f in $files; do
   >     mkdir -p `dirname $f`
@@ -112,7 +114,7 @@ setup a repository for tests
 Reference size:
   $ f -s file
   file: size=135168
-  $ f -s .hg/store/data/file*
+  $ f -s .hg/store/data*/file*
   .hg/store/data/file.d: size=267307
   .hg/store/data/file.i: size=320
 
@@ -140,7 +142,7 @@ but truncate the index and the data to r
 Reference size:
   $ f -s file
   file: size=1024
-  $ f -s .hg/store/data/file*
+  $ f -s .hg/store/data*/file*
   .hg/store/data/file.i: size=1174
 
   $ cat > .hg/hgrc <<EOF
@@ -162,11 +164,12 @@ Reference size:
 The inline revlog still exist, but a split version exist next to it
 
   $ cat .hg/store/journal | tr '\0' ' ' | grep '\.s'
-  [1]
-  $ f -s .hg/store/data/file*
+  data/some_dir/sub_dir/foo_bar.i.s/tutu.i 1174
+  data/some_dir/sub_dir/foo_bar.i.s/tutu.d 0
+  $ f -s .hg/store/data*/file*
+  .hg/store/data-s/file: size=320
   .hg/store/data/file.d: size=267307
   .hg/store/data/file.i: size=132395
-  .hg/store/data/file.i.s: size=320
 
 
 The first file.i entry should match the "Reference size" above.
@@ -177,19 +180,19 @@ A "temporary file" entry exist for the s
   $ cat .hg/store/journal | tr -s '\000' ' ' | grep data/file
   data/file.i 1174
   data/file.d 0
-  $ cat .hg/store/journal.backupfiles | tr -s '\000' ' ' | tr -s '\00' ' '| grep data/file
+  $ cat .hg/store/journal.backupfiles | tr -s '\000' ' ' | tr -s '\00' ' '| grep 'data.*/file'
    data/file.i data/journal.backup.file.i 0
-   data/file.i.s 0
+   data-s/file 0
 
 recover is rolling the split back, the fncache is still valid
 
   $ hg recover
   rolling back interrupted transaction
   (verify step skipped, run `hg verify` to check your repository content)
-  $ f -s .hg/store/data/file*
+  $ f -s .hg/store/data*/file*
   .hg/store/data/file.i: size=1174
   $ hg tip
-  changeset:   1:cc8dfb126534
+  changeset:   1:64b04c8dc267
   tag:         tip
   user:        test
   date:        Thu Jan 01 00:00:00 1970 +0000
@@ -214,7 +217,7 @@ where the data file is left as garbage.
 Reference size:
   $ f -s file
   file: size=1024
-  $ f -s .hg/store/data/file*
+  $ f -s .hg/store/data*/file*
   .hg/store/data/file.i: size=1174
 
   $ cat > .hg/hgrc <<EOF
@@ -242,12 +245,12 @@ Reference size:
 
 The inline revlog still exist, but a split version exist next to it
 
-  $ f -s .hg/store/data/file*
+  $ f -s .hg/store/data*/file*
+  .hg/store/data-s/file: size=320
   .hg/store/data/file.d: size=267307
   .hg/store/data/file.i: size=132395
-  .hg/store/data/file.i.s: size=320
 
-  $ cat .hg/store/journal | tr -s '\000' ' ' | grep data/file
+  $ cat .hg/store/journal | tr -s '\000' ' ' | grep 'data.*/file'
   data/file.i 1174
   data/file.d 0
 
@@ -256,10 +259,10 @@ recover is rolling the split back, the f
   $ hg recover
   rolling back interrupted transaction
   (verify step skipped, run `hg verify` to check your repository content)
-  $ f -s .hg/store/data/file*
+  $ f -s .hg/store/data*/file*
   .hg/store/data/file.i: size=1174
   $ hg tip
-  changeset:   1:cc8dfb126534
+  changeset:   1:64b04c8dc267
   tag:         tip
   user:        test
   date:        Thu Jan 01 00:00:00 1970 +0000
@@ -279,7 +282,7 @@ Now retry the procedure but intercept th
 Reference size:
   $ f -s file
   file: size=1024
-  $ f -s .hg/store/data/file*
+  $ f -s .hg/store/data*/file*
   .hg/store/data/file.i: size=1174
 
   $ cat > .hg/hgrc <<EOF
@@ -307,11 +310,11 @@ Reference size:
 
 The inline revlog was over written on disk
 
-  $ f -s .hg/store/data/file*
+  $ f -s .hg/store/data*/file*
   .hg/store/data/file.d: size=267307
   .hg/store/data/file.i: size=320
 
-  $ cat .hg/store/journal | tr -s '\000' ' ' | grep data/file
+  $ cat .hg/store/journal | tr -s '\000' ' ' | grep 'data.*/file'
   data/file.i 1174
   data/file.d 0
 
@@ -320,10 +323,10 @@ recover is rolling the split back, the f
   $ hg recover
   rolling back interrupted transaction
   (verify step skipped, run `hg verify` to check your repository content)
-  $ f -s .hg/store/data/file*
+  $ f -s .hg/store/data*/file*
   .hg/store/data/file.i: size=1174
   $ hg tip
-  changeset:   1:cc8dfb126534
+  changeset:   1:64b04c8dc267
   tag:         tip
   user:        test
   date:        Thu Jan 01 00:00:00 1970 +0000
@@ -357,13 +360,13 @@ Repeat the original test but let hg roll
 
 The split was rollback
 
-  $ f -s .hg/store/data/file*
+  $ f -s .hg/store/data*/file*
   .hg/store/data/file.d: size=0
   .hg/store/data/file.i: size=1174
 
 
   $ hg tip
-  changeset:   1:cc8dfb126534
+  changeset:   1:64b04c8dc267
   tag:         tip
   user:        test
   date:        Thu Jan 01 00:00:00 1970 +0000
diff --git a/tests/test-upgrade-repo.t b/tests/test-upgrade-repo.t
--- a/tests/test-upgrade-repo.t
+++ b/tests/test-upgrade-repo.t
@@ -839,6 +839,7 @@ store directory has files we expect
   00changelog.i
   00manifest.i
   data
+  data-s
   fncache
   phaseroots
   requires
@@ -862,6 +863,7 @@ old store should be backed up
   00changelog.i
   00manifest.i
   data
+  data-s
   fncache
   phaseroots
   requires