fs/ntfs3: Restore correct state after ENOSPC in attr_data_get_block

Added new function ntfs_check_for_free_space.
Added undo mechanism in attr_data_get_block.
Fixes xfstest generic/083

Signed-off-by: Konstantin Komarov <almaz.alexandrovich@paragon-software.com>

diff --git a/fs/ntfs3/attrib.c b/fs/ntfs3/attrib.c
index 91ea73e6f4fe2f9f185cb18ca7fdd0eb7ecee12f..5e6bafb10f42d5d8e8ecb83f984dbee195db7049 100644 (file)
--- a/fs/ntfs3/attrib.c
+++ b/fs/ntfs3/attrib.c
@@ -891,8 +891,10 @@ int attr_data_get_block(struct ntfs_inode *ni, CLST vcn, CLST clen, CLST *lcn,
        struct ATTR_LIST_ENTRY *le, *le_b;
        struct mft_inode *mi, *mi_b;
        CLST hint, svcn, to_alloc, evcn1, next_svcn, asize, end, vcn0, alen;
+       CLST alloc, evcn;
        unsigned fr;
-       u64 total_size;
+       u64 total_size, total_size0;
+       int step = 0;
 
        if (new)
                *new = false;
@@ -932,7 +934,12 @@ int attr_data_get_block(struct ntfs_inode *ni, CLST vcn, CLST clen, CLST *lcn,
 
        asize = le64_to_cpu(attr_b->nres.alloc_size) >> cluster_bits;
        if (vcn >= asize) {
-               err = -EINVAL;
+               if (new) {
+                       err = -EINVAL;
+               } else {
+                       *len = 1;
+                       *lcn = SPARSE_LCN;
+               }
                goto out;
        }
 
@@ -1036,10 +1043,12 @@ int attr_data_get_block(struct ntfs_inode *ni, CLST vcn, CLST clen, CLST *lcn,
        if (err)
                goto out;
        *new = true;
+       step = 1;
 
        end = vcn + alen;
-       total_size = le64_to_cpu(attr_b->nres.total_size) +
-                    ((u64)alen << cluster_bits);
+       /* Save 'total_size0' to restore if error. */
+       total_size0 = le64_to_cpu(attr_b->nres.total_size);
+       total_size = total_size0 + ((u64)alen << cluster_bits);
 
        if (vcn != vcn0) {
                if (!run_lookup_entry(run, vcn0, lcn, len, NULL)) {
@@ -1081,7 +1090,7 @@ repack:
                if (!ni->attr_list.size) {
                        err = ni_create_attr_list(ni);
                        if (err)
-                               goto out;
+                               goto undo1;
                        /* Layout of records is changed. */
                        le_b = NULL;
                        attr_b = ni_find_attr(ni, NULL, &le_b, ATTR_DATA, NULL,
@@ -1098,67 +1107,83 @@ repack:
                }
        }
 
+       /* 
+        * The code below may require additional cluster (to extend attribute list)
+        * and / or one MFT record 
+        * It is too complex to undo operations if -ENOSPC occurs deep inside 
+        * in 'ni_insert_nonresident'.
+        * Return in advance -ENOSPC here if there are no free cluster and no free MFT.
+        */
+       if (!ntfs_check_for_free_space(sbi, 1, 1)) {
+               /* Undo step 1. */
+               err = -ENOSPC;
+               goto undo1;
+       }
+
+       step = 2;
        svcn = evcn1;
 
        /* Estimate next attribute. */
        attr = ni_find_attr(ni, attr, &le, ATTR_DATA, NULL, 0, &svcn, &mi);
 
-       if (attr) {
-               CLST alloc = bytes_to_cluster(
-                       sbi, le64_to_cpu(attr_b->nres.alloc_size));
-               CLST evcn = le64_to_cpu(attr->nres.evcn);
-
-               if (end < next_svcn)
-                       end = next_svcn;
-               while (end > evcn) {
-                       /* Remove segment [svcn : evcn). */
-                       mi_remove_attr(NULL, mi, attr);
-
-                       if (!al_remove_le(ni, le)) {
-                               err = -EINVAL;
-                               goto out;
-                       }
+       if (!attr) {
+               /* Insert new attribute segment. */
+               goto ins_ext;
+       }
 
-                       if (evcn + 1 >= alloc) {
-                               /* Last attribute segment. */
-                               evcn1 = evcn + 1;
-                               goto ins_ext;
-                       }
+       /* Try to update existed attribute segment. */
+       alloc = bytes_to_cluster(sbi, le64_to_cpu(attr_b->nres.alloc_size));
+       evcn = le64_to_cpu(attr->nres.evcn);
 
-                       if (ni_load_mi(ni, le, &mi)) {
-                               attr = NULL;
-                               goto out;
-                       }
+       if (end < next_svcn)
+               end = next_svcn;
+       while (end > evcn) {
+               /* Remove segment [svcn : evcn). */
+               mi_remove_attr(NULL, mi, attr);
 
-                       attr = mi_find_attr(mi, NULL, ATTR_DATA, NULL, 0,
-                                           &le->id);
-                       if (!attr) {
-                               err = -EINVAL;
-                               goto out;
-                       }
-                       svcn = le64_to_cpu(attr->nres.svcn);
-                       evcn = le64_to_cpu(attr->nres.evcn);
+               if (!al_remove_le(ni, le)) {
+                       err = -EINVAL;
+                       goto out;
                }
 
-               if (end < svcn)
-                       end = svcn;
+               if (evcn + 1 >= alloc) {
+                       /* Last attribute segment. */
+                       evcn1 = evcn + 1;
+                       goto ins_ext;
+               }
 
-               err = attr_load_runs(attr, ni, run, &end);
-               if (err)
+               if (ni_load_mi(ni, le, &mi)) {
+                       attr = NULL;
                        goto out;
+               }
 
-               evcn1 = evcn + 1;
-               attr->nres.svcn = cpu_to_le64(next_svcn);
-               err = mi_pack_runs(mi, attr, run, evcn1 - next_svcn);
-               if (err)
+               attr = mi_find_attr(mi, NULL, ATTR_DATA, NULL, 0, &le->id);
+               if (!attr) {
+                       err = -EINVAL;
                        goto out;
+               }
+               svcn = le64_to_cpu(attr->nres.svcn);
+               evcn = le64_to_cpu(attr->nres.evcn);
+       }
 
-               le->vcn = cpu_to_le64(next_svcn);
-               ni->attr_list.dirty = true;
-               mi->dirty = true;
+       if (end < svcn)
+               end = svcn;
+
+       err = attr_load_runs(attr, ni, run, &end);
+       if (err)
+               goto out;
+
+       evcn1 = evcn + 1;
+       attr->nres.svcn = cpu_to_le64(next_svcn);
+       err = mi_pack_runs(mi, attr, run, evcn1 - next_svcn);
+       if (err)
+               goto out;
+
+       le->vcn = cpu_to_le64(next_svcn);
+       ni->attr_list.dirty = true;
+       mi->dirty = true;
+       next_svcn = le64_to_cpu(attr->nres.evcn) + 1;
 
-               next_svcn = le64_to_cpu(attr->nres.evcn) + 1;
-       }
 ins_ext:
        if (evcn1 > next_svcn) {
                err = ni_insert_nonresident(ni, ATTR_DATA, NULL, 0, run,
@@ -1170,10 +1195,26 @@ ins_ext:
 ok:
        run_truncate_around(run, vcn);
 out:
+       if (err && step > 1) {
+               /* Too complex to restore. */
+               _ntfs_bad_inode(&ni->vfs_inode);
+       }
        up_write(&ni->file.run_lock);
        ni_unlock(ni);
 
        return err;
+
+undo1:
+       /* Undo step1. */
+       attr_b->nres.total_size = cpu_to_le64(total_size0);
+       inode_set_bytes(&ni->vfs_inode, total_size0);
+
+       if (run_deallocate_ex(sbi, run, vcn, alen, NULL, false) ||
+           !run_add_entry(run, vcn, SPARSE_LCN, alen, false) ||
+           mi_pack_runs(mi, attr, run, max(end, evcn1) - svcn)) {
+               _ntfs_bad_inode(&ni->vfs_inode);
+       }
+       goto out;
 }
 
 int attr_data_read_resident(struct ntfs_inode *ni, struct page *page)

diff --git a/fs/ntfs3/fsntfs.c b/fs/ntfs3/fsntfs.c
index b68a7b78026294ed699de5e012bd50935483b7e8..4f04e8594a8fea64300b4807df020150944b0619 100644 (file)
--- a/fs/ntfs3/fsntfs.c
+++ b/fs/ntfs3/fsntfs.c
@@ -443,6 +443,39 @@ up_write:
        return err;
 }
 
+/*
+ * ntfs_check_for_free_space
+ *
+ * Check if it is possible to allocate 'clen' clusters and 'mlen' Mft records
+ */
+bool ntfs_check_for_free_space(struct ntfs_sb_info *sbi, CLST clen, CLST mlen)
+{
+       size_t free, zlen, avail;
+       struct wnd_bitmap *wnd;
+
+       wnd = &sbi->used.bitmap;
+       down_read_nested(&wnd->rw_lock, BITMAP_MUTEX_CLUSTERS);
+       free = wnd_zeroes(wnd);
+       zlen = wnd_zone_len(wnd);
+       up_read(&wnd->rw_lock);
+
+       if (free < zlen + clen)
+               return false;
+
+       avail = free - (zlen + clen);
+
+       wnd = &sbi->mft.bitmap;
+       down_read_nested(&wnd->rw_lock, BITMAP_MUTEX_MFT);
+       free = wnd_zeroes(wnd);
+       zlen = wnd_zone_len(wnd);
+       up_read(&wnd->rw_lock);
+
+       if (free >= zlen + mlen)
+               return true;
+
+       return avail >= bytes_to_cluster(sbi, mlen << sbi->record_bits);
+}
+
 /*
  * ntfs_extend_mft - Allocate additional MFT records.
  *

diff --git a/fs/ntfs3/ntfs_fs.h b/fs/ntfs3/ntfs_fs.h
index 776993ae498b27ec70ce11423a34295e03095232..bfb7493c521649488f40b38d275d6c81e4cd83b2 100644 (file)
--- a/fs/ntfs3/ntfs_fs.h
+++ b/fs/ntfs3/ntfs_fs.h
@@ -588,6 +588,7 @@ int ntfs_loadlog_and_replay(struct ntfs_inode *ni, struct ntfs_sb_info *sbi);
 int ntfs_look_for_free_space(struct ntfs_sb_info *sbi, CLST lcn, CLST len,
                             CLST *new_lcn, CLST *new_len,
                             enum ALLOCATE_OPT opt);
+bool ntfs_check_for_free_space(struct ntfs_sb_info *sbi, CLST clen, CLST mlen);
 int ntfs_look_free_mft(struct ntfs_sb_info *sbi, CLST *rno, bool mft,
                       struct ntfs_inode *ni, struct mft_inode **mi);
 void ntfs_mark_rec_free(struct ntfs_sb_info *sbi, CLST rno, bool is_mft);