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NTFS: Fix cluster (de)allocators to work when the runlist is NULL and more

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importantly to take a locked runlist rather than them locking it
      which leads to lock reversal.

Signed-off-by: Anton Altaparmakov <aia21@cantab.net>
This commit is contained in:
Anton Altaparmakov
2005-09-08 21:09:06 +01:00
parent 807c453de7
commit bbf1813fb8
4 changed files with 32 additions and 33 deletions
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39
fs/ntfs/lcnalloc.c
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@@ -54,6 +54,8 @@ int ntfs_cluster_free_from_rl_nolock(ntfs_volume *vol,
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_volume *vol, const VCN start_vcn,
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, const VCN start_vcn, s64 count,
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, const VCN start_vcn, s64 count,
/* 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, const VCN start_vcn, s64 count,
/* 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, const VCN start_vcn, s64 count,
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 "