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Date: Wed, 13 Jul 2022 19:46:07 +0300
From: Konstantin Komarov <almaz.alexandrovich@...agon-software.com>
To: <ntfs3@...ts.linux.dev>
CC: <linux-kernel@...r.kernel.org>, <linux-fsdevel@...r.kernel.org>
Subject: [PATCH 3/6] fs/ntfs3: Refactoring attr_punch_hole to restore after
errors
Added comments to code
Added new function run_clone to make a copy of run
Added done and undo labels for restoring after errors
Signed-off-by: Konstantin Komarov <almaz.alexandrovich@...agon-software.com>
---
fs/ntfs3/attrib.c | 117 ++++++++++++++++++++++++++++++---------------
fs/ntfs3/ntfs_fs.h | 1 +
fs/ntfs3/run.c | 25 ++++++++++
3 files changed, 105 insertions(+), 38 deletions(-)
diff --git a/fs/ntfs3/attrib.c b/fs/ntfs3/attrib.c
index 7bcae3094712..24d545041787 100644
--- a/fs/ntfs3/attrib.c
+++ b/fs/ntfs3/attrib.c
@@ -140,7 +140,10 @@ static int run_deallocate_ex(struct ntfs_sb_info *sbi, struct runs_tree *run,
}
if (lcn != SPARSE_LCN) {
- mark_as_free_ex(sbi, lcn, clen, trim);
+ if (sbi) {
+ /* mark bitmap range [lcn + clen) as free and trim clusters. */
+ mark_as_free_ex(sbi, lcn, clen, trim);
+ }
dn += clen;
}
@@ -2002,10 +2005,11 @@ int attr_punch_hole(struct ntfs_inode *ni, u64 vbo, u64 bytes, u32 *frame_size)
struct ATTRIB *attr = NULL, *attr_b;
struct ATTR_LIST_ENTRY *le, *le_b;
struct mft_inode *mi, *mi_b;
- CLST svcn, evcn1, vcn, len, end, alen, dealloc, next_svcn;
+ CLST svcn, evcn1, vcn, len, end, alen, hole, next_svcn;
u64 total_size, alloc_size;
u32 mask;
__le16 a_flags;
+ struct runs_tree run2;
if (!bytes)
return 0;
@@ -2057,6 +2061,9 @@ int attr_punch_hole(struct ntfs_inode *ni, u64 vbo, u64 bytes, u32 *frame_size)
}
down_write(&ni->file.run_lock);
+ run_init(&run2);
+ run_truncate(run, 0);
+
/*
* Enumerate all attribute segments and punch hole where necessary.
*/
@@ -2064,7 +2071,7 @@ int attr_punch_hole(struct ntfs_inode *ni, u64 vbo, u64 bytes, u32 *frame_size)
vcn = vbo >> sbi->cluster_bits;
len = bytes >> sbi->cluster_bits;
end = vcn + len;
- dealloc = 0;
+ hole = 0;
svcn = le64_to_cpu(attr_b->nres.svcn);
evcn1 = le64_to_cpu(attr_b->nres.evcn) + 1;
@@ -2076,14 +2083,14 @@ int attr_punch_hole(struct ntfs_inode *ni, u64 vbo, u64 bytes, u32 *frame_size)
mi = mi_b;
} else if (!le_b) {
err = -EINVAL;
- goto out;
+ goto bad_inode;
} else {
le = le_b;
attr = ni_find_attr(ni, attr_b, &le, ATTR_DATA, NULL, 0, &vcn,
&mi);
if (!attr) {
err = -EINVAL;
- goto out;
+ goto bad_inode;
}
svcn = le64_to_cpu(attr->nres.svcn);
@@ -2091,69 +2098,91 @@ int attr_punch_hole(struct ntfs_inode *ni, u64 vbo, u64 bytes, u32 *frame_size)
}
while (svcn < end) {
- CLST vcn1, zero, dealloc2;
+ CLST vcn1, zero, hole2 = hole;
err = attr_load_runs(attr, ni, run, &svcn);
if (err)
- goto out;
+ goto done;
vcn1 = max(vcn, svcn);
zero = min(end, evcn1) - vcn1;
- dealloc2 = dealloc;
- err = run_deallocate_ex(sbi, run, vcn1, zero, &dealloc, true);
+ /*
+ * Check range [vcn1 + zero).
+ * Calculate how many clusters there are.
+ * Don't do any destructive actions.
+ */
+ err = run_deallocate_ex(NULL, run, vcn1, zero, &hole2, false);
if (err)
- goto out;
+ goto done;
- if (dealloc2 == dealloc) {
- /* Looks like the required range is already sparsed. */
- } else {
- if (!run_add_entry(run, vcn1, SPARSE_LCN, zero,
- false)) {
- err = -ENOMEM;
- goto out;
- }
+ /* Check if required range is already hole. */
+ if (hole2 == hole)
+ goto next_attr;
- err = mi_pack_runs(mi, attr, run, evcn1 - svcn);
+ /* Make a clone of run to undo. */
+ err = run_clone(run, &run2);
+ if (err)
+ goto done;
+
+ /* Make a hole range (sparse) [vcn1 + zero). */
+ if (!run_add_entry(run, vcn1, SPARSE_LCN, zero, false)) {
+ err = -ENOMEM;
+ goto done;
+ }
+
+ /* Update run in attribute segment. */
+ err = mi_pack_runs(mi, attr, run, evcn1 - svcn);
+ if (err)
+ goto done;
+ next_svcn = le64_to_cpu(attr->nres.evcn) + 1;
+ if (next_svcn < evcn1) {
+ /* Insert new attribute segment. */
+ err = ni_insert_nonresident(ni, ATTR_DATA, NULL, 0, run,
+ next_svcn,
+ evcn1 - next_svcn, a_flags,
+ &attr, &mi, &le);
if (err)
- goto out;
- next_svcn = le64_to_cpu(attr->nres.evcn) + 1;
- if (next_svcn < evcn1) {
- err = ni_insert_nonresident(ni, ATTR_DATA, NULL,
- 0, run, next_svcn,
- evcn1 - next_svcn,
- a_flags, &attr, &mi,
- &le);
- if (err)
- goto out;
- /* Layout of records maybe changed. */
- attr_b = NULL;
- }
+ goto undo_punch;
+
+ /* Layout of records maybe changed. */
+ attr_b = NULL;
}
+
+ /* Real deallocate. Should not fail. */
+ run_deallocate_ex(sbi, &run2, vcn1, zero, &hole, true);
+
+next_attr:
/* Free all allocated memory. */
run_truncate(run, 0);
if (evcn1 >= alen)
break;
+ /* Get next attribute segment. */
attr = ni_enum_attr_ex(ni, attr, &le, &mi);
if (!attr) {
err = -EINVAL;
- goto out;
+ goto bad_inode;
}
svcn = le64_to_cpu(attr->nres.svcn);
evcn1 = le64_to_cpu(attr->nres.evcn) + 1;
}
- total_size -= (u64)dealloc << sbi->cluster_bits;
+done:
+ if (!hole)
+ goto out;
+
if (!attr_b) {
attr_b = ni_find_attr(ni, NULL, NULL, ATTR_DATA, NULL, 0, NULL,
&mi_b);
if (!attr_b) {
err = -EINVAL;
- goto out;
+ goto bad_inode;
}
}
+
+ total_size -= (u64)hole << sbi->cluster_bits;
attr_b->nres.total_size = cpu_to_le64(total_size);
mi_b->dirty = true;
@@ -2163,11 +2192,23 @@ int attr_punch_hole(struct ntfs_inode *ni, u64 vbo, u64 bytes, u32 *frame_size)
mark_inode_dirty(&ni->vfs_inode);
out:
+ run_close(&run2);
up_write(&ni->file.run_lock);
- if (err)
- _ntfs_bad_inode(&ni->vfs_inode);
-
return err;
+
+bad_inode:
+ _ntfs_bad_inode(&ni->vfs_inode);
+ goto out;
+
+undo_punch:
+ /*
+ * Restore packed runs.
+ * 'mi_pack_runs' should not fail, cause we restore original.
+ */
+ if (mi_pack_runs(mi, attr, &run2, evcn1 - svcn))
+ goto bad_inode;
+
+ goto done;
}
/*
diff --git a/fs/ntfs3/ntfs_fs.h b/fs/ntfs3/ntfs_fs.h
index c3e17090effc..23f93c263091 100644
--- a/fs/ntfs3/ntfs_fs.h
+++ b/fs/ntfs3/ntfs_fs.h
@@ -798,6 +798,7 @@ int run_unpack_ex(struct runs_tree *run, struct ntfs_sb_info *sbi, CLST ino,
#define run_unpack_ex run_unpack
#endif
int run_get_highest_vcn(CLST vcn, const u8 *run_buf, u64 *highest_vcn);
+int run_clone(const struct runs_tree *run, struct runs_tree *new_run);
/* Globals from super.c */
void *ntfs_set_shared(void *ptr, u32 bytes);
diff --git a/fs/ntfs3/run.c b/fs/ntfs3/run.c
index e4bd46b02531..ed09b7a6f6e5 100644
--- a/fs/ntfs3/run.c
+++ b/fs/ntfs3/run.c
@@ -1157,3 +1157,28 @@ int run_get_highest_vcn(CLST vcn, const u8 *run_buf, u64 *highest_vcn)
*highest_vcn = vcn64 - 1;
return 0;
}
+
+/*
+ * run_clone
+ *
+ * Make a copy of run
+ */
+int run_clone(const struct runs_tree *run, struct runs_tree *new_run)
+{
+ size_t bytes = run->count * sizeof(struct ntfs_run);
+
+ if (bytes > new_run->allocated) {
+ struct ntfs_run *new_ptr = kvmalloc(bytes, GFP_KERNEL);
+
+ if (!new_ptr)
+ return -ENOMEM;
+
+ kvfree(new_run->runs);
+ new_run->runs = new_ptr;
+ new_run->allocated = bytes;
+ }
+
+ memcpy(new_run->runs, run->runs, bytes);
+ new_run->count = run->count;
+ return 0;
+}
--
2.37.0
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