[PATCH 15/25] NTFS: Fix cluster (de)allocators to work when the runlist is NULL and more
importantly to take a locked runlist rather than them locking it
which leads to lock reversal.
Signed-off-by: Anton Altaparmakov <[email protected]>
---
fs/ntfs/ChangeLog | 3 +++
fs/ntfs/lcnalloc.c | 39 ++++++++++++++++-----------------------
fs/ntfs/lcnalloc.h | 21 ++++++++++++---------
fs/ntfs/mft.c | 2 +-
4 files changed, 32 insertions(+), 33 deletions(-)
bbf1813fb8ff9d21171bf22e6d1f0e0393601e86
diff --git a/fs/ntfs/ChangeLog b/fs/ntfs/ChangeLog
--- a/fs/ntfs/ChangeLog
+++ b/fs/ntfs/ChangeLog
@@ -70,6 +70,9 @@ ToDo/Notes:
- Add BUG() checks to ntfs_attr_make_non_resident() and ntfs_attr_set()
to ensure that these functions are never called for compressed or
encrypted attributes.
+ - Fix cluster (de)allocators to work when the runlist is NULL and more
+ importantly to take a locked runlist rather than them locking it
+ which leads to lock reversal.
2.1.23 - Implement extension of resident files and make writing safe as well as
many bug fixes, cleanups, and enhancements...
diff --git a/fs/ntfs/lcnalloc.c b/fs/ntfs/lcnalloc.c
--- a/fs/ntfs/lcnalloc.c
+++ b/fs/ntfs/lcnalloc.c
@@ -54,6 +54,8 @@ int ntfs_cluster_free_from_rl_nolock(ntf
int ret = 0;
ntfs_debug("Entering.");
+ if (!rl)
+ return 0;
for (; rl->length; rl++) {
int err;
@@ -163,17 +165,9 @@ runlist_element *ntfs_cluster_alloc(ntfs
BUG_ON(zone < FIRST_ZONE);
BUG_ON(zone > LAST_ZONE);
- /* Return empty runlist if @count == 0 */
- // FIXME: Do we want to just return NULL instead? (AIA)
- if (!count) {
- rl = ntfs_malloc_nofs(PAGE_SIZE);
- if (!rl)
- return ERR_PTR(-ENOMEM);
- rl[0].vcn = start_vcn;
- rl[0].lcn = LCN_RL_NOT_MAPPED;
- rl[0].length = 0;
- return rl;
- }
+ /* Return NULL if @count is zero. */
+ if (!count)
+ return NULL;
/* Take the lcnbmp lock for writing. */
down_write(&vol->lcnbmp_lock);
/*
@@ -788,7 +782,8 @@ out:
* @vi: vfs inode whose runlist describes the clusters to free
* @start_vcn: vcn in the runlist of @vi at which to start freeing clusters
* @count: number of clusters to free or -1 for all clusters
- * @is_rollback: if TRUE this is a rollback operation
+ * @write_locked: true if the runlist is locked for writing
+ * @is_rollback: true if this is a rollback operation
*
* Free @count clusters starting at the cluster @start_vcn in the runlist
* described by the vfs inode @vi.
@@ -806,17 +801,17 @@ out:
* Return the number of deallocated clusters (not counting sparse ones) on
* success and -errno on error.
*
- * Locking: - The runlist described by @vi must be unlocked on entry and is
- * unlocked on return.
- * - This function takes the runlist lock of @vi for reading and
- * sometimes for writing and sometimes modifies the runlist.
+ * Locking: - The runlist described by @vi must be locked on entry and is
+ * locked on return. Note if the runlist is locked for reading the
+ * lock may be dropped and reacquired. Note the runlist may be
+ * modified when needed runlist fragments need to be mapped.
* - The volume lcn bitmap must be unlocked on entry and is unlocked
* on return.
* - This function takes the volume lcn bitmap lock for writing and
* modifies the bitmap contents.
*/
s64 __ntfs_cluster_free(struct inode *vi, const VCN start_vcn, s64 count,
- const BOOL is_rollback)
+ const BOOL write_locked, const BOOL is_rollback)
{
s64 delta, to_free, total_freed, real_freed;
ntfs_inode *ni;
@@ -848,8 +843,7 @@ s64 __ntfs_cluster_free(struct inode *vi
total_freed = real_freed = 0;
- down_read(&ni->runlist.lock);
- rl = ntfs_attr_find_vcn_nolock(ni, start_vcn, FALSE);
+ rl = ntfs_attr_find_vcn_nolock(ni, start_vcn, write_locked);
if (IS_ERR(rl)) {
if (!is_rollback)
ntfs_error(vol->sb, "Failed to find first runlist "
@@ -903,7 +897,7 @@ s64 __ntfs_cluster_free(struct inode *vi
/* Attempt to map runlist. */
vcn = rl->vcn;
- rl = ntfs_attr_find_vcn_nolock(ni, vcn, FALSE);
+ rl = ntfs_attr_find_vcn_nolock(ni, vcn, write_locked);
if (IS_ERR(rl)) {
err = PTR_ERR(rl);
if (!is_rollback)
@@ -950,7 +944,6 @@ s64 __ntfs_cluster_free(struct inode *vi
/* Update the total done clusters. */
total_freed += to_free;
}
- up_read(&ni->runlist.lock);
if (likely(!is_rollback))
up_write(&vol->lcnbmp_lock);
@@ -960,7 +953,6 @@ s64 __ntfs_cluster_free(struct inode *vi
ntfs_debug("Done.");
return real_freed;
err_out:
- up_read(&ni->runlist.lock);
if (is_rollback)
return err;
/* If no real clusters were freed, no need to rollback. */
@@ -973,7 +965,8 @@ err_out:
* If rollback fails, set the volume errors flag, emit an error
* message, and return the error code.
*/
- delta = __ntfs_cluster_free(vi, start_vcn, total_freed, TRUE);
+ delta = __ntfs_cluster_free(vi, start_vcn, total_freed, write_locked,
+ TRUE);
if (delta < 0) {
ntfs_error(vol->sb, "Failed to rollback (error %i). Leaving "
"inconsistent metadata! Unmount and run "
diff --git a/fs/ntfs/lcnalloc.h b/fs/ntfs/lcnalloc.h
--- a/fs/ntfs/lcnalloc.h
+++ b/fs/ntfs/lcnalloc.h
@@ -43,13 +43,14 @@ extern runlist_element *ntfs_cluster_all
const NTFS_CLUSTER_ALLOCATION_ZONES zone);
extern s64 __ntfs_cluster_free(struct inode *vi, const VCN start_vcn,
- s64 count, const BOOL is_rollback);
+ s64 count, const BOOL write_locked, const BOOL is_rollback);
/**
* ntfs_cluster_free - free clusters on an ntfs volume
* @vi: vfs inode whose runlist describes the clusters to free
* @start_vcn: vcn in the runlist of @vi at which to start freeing clusters
* @count: number of clusters to free or -1 for all clusters
+ * @write_locked: true if the runlist is locked for writing
*
* Free @count clusters starting at the cluster @start_vcn in the runlist
* described by the vfs inode @vi.
@@ -64,19 +65,19 @@ extern s64 __ntfs_cluster_free(struct in
* Return the number of deallocated clusters (not counting sparse ones) on
* success and -errno on error.
*
- * Locking: - The runlist described by @vi must be unlocked on entry and is
- * unlocked on return.
- * - This function takes the runlist lock of @vi for reading and
- * sometimes for writing and sometimes modifies the runlist.
+ * Locking: - The runlist described by @vi must be locked on entry and is
+ * locked on return. Note if the runlist is locked for reading the
+ * lock may be dropped and reacquired. Note the runlist may be
+ * modified when needed runlist fragments need to be mapped.
* - The volume lcn bitmap must be unlocked on entry and is unlocked
* on return.
* - This function takes the volume lcn bitmap lock for writing and
* modifies the bitmap contents.
*/
static inline s64 ntfs_cluster_free(struct inode *vi, const VCN start_vcn,
- s64 count)
+ s64 count, const BOOL write_locked)
{
- return __ntfs_cluster_free(vi, start_vcn, count, FALSE);
+ return __ntfs_cluster_free(vi, start_vcn, count, write_locked, FALSE);
}
extern int ntfs_cluster_free_from_rl_nolock(ntfs_volume *vol,
@@ -93,8 +94,10 @@ extern int ntfs_cluster_free_from_rl_nol
*
* Return 0 on success and -errno on error.
*
- * Locking: This function takes the volume lcn bitmap lock for writing and
- * modifies the bitmap contents.
+ * Locking: - This function takes the volume lcn bitmap lock for writing and
+ * modifies the bitmap contents.
+ * - The caller must have locked the runlist @rl for reading or
+ * writing.
*/
static inline int ntfs_cluster_free_from_rl(ntfs_volume *vol,
const runlist_element *rl)
diff --git a/fs/ntfs/mft.c b/fs/ntfs/mft.c
--- a/fs/ntfs/mft.c
+++ b/fs/ntfs/mft.c
@@ -1953,7 +1953,7 @@ restore_undo_alloc:
a = ctx->attr;
a->data.non_resident.highest_vcn = cpu_to_sle64(old_last_vcn - 1);
undo_alloc:
- if (ntfs_cluster_free(vol->mft_ino, old_last_vcn, -1) < 0) {
+ if (ntfs_cluster_free(vol->mft_ino, old_last_vcn, -1, TRUE) < 0) {
ntfs_error(vol->sb, "Failed to free clusters from mft data "
"attribute.%s", es);
NVolSetErrors(vol);
-
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