diff options
| -rw-r--r-- | fs/ntfs/ChangeLog | 3 | ||||
| -rw-r--r-- | fs/ntfs/runlist.c | 68 |
2 files changed, 53 insertions, 18 deletions
diff --git a/fs/ntfs/ChangeLog b/fs/ntfs/ChangeLog index c3bf17be0e1..c5bbedff5ae 100644 --- a/fs/ntfs/ChangeLog +++ b/fs/ntfs/ChangeLog @@ -40,6 +40,9 @@ ToDo/Notes: - Add fs/ntfs/malloc.h::ntfs_malloc_nofs_nofail() which is analogous to ntfs_malloc_nofs() but it performs allocations with __GFP_NOFAIL and hence cannot fail. + - Use ntfs_malloc_nofs_nofail() in the two critical regions in + fs/ntfs/runlist.c::ntfs_runlists_merge(). This means we no longer + need to panic() if the allocation fails as it now cannot fail. 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/runlist.c b/fs/ntfs/runlist.c index 758855b0414..3bb4a57d1fa 100644 --- a/fs/ntfs/runlist.c +++ b/fs/ntfs/runlist.c @@ -35,7 +35,7 @@ static inline void ntfs_rl_mm(runlist_element *base, int dst, int src, int size) { if (likely((dst != src) && (size > 0))) - memmove(base + dst, base + src, size * sizeof (*base)); + memmove(base + dst, base + src, size * sizeof(*base)); } /** @@ -95,6 +95,51 @@ static inline runlist_element *ntfs_rl_realloc(runlist_element *rl, } /** + * ntfs_rl_realloc_nofail - Reallocate memory for runlists + * @rl: original runlist + * @old_size: number of runlist elements in the original runlist @rl + * @new_size: number of runlist elements we need space for + * + * As the runlists grow, more memory will be required. To prevent the + * kernel having to allocate and reallocate large numbers of small bits of + * memory, this function returns an entire page of memory. + * + * This function guarantees that the allocation will succeed. It will sleep + * for as long as it takes to complete the allocation. + * + * It is up to the caller to serialize access to the runlist @rl. + * + * N.B. If the new allocation doesn't require a different number of pages in + * memory, the function will return the original pointer. + * + * On success, return a pointer to the newly allocated, or recycled, memory. + * On error, return -errno. The following error codes are defined: + * -ENOMEM - Not enough memory to allocate runlist array. + * -EINVAL - Invalid parameters were passed in. + */ +static inline runlist_element *ntfs_rl_realloc_nofail(runlist_element *rl, + int old_size, int new_size) +{ + runlist_element *new_rl; + + old_size = PAGE_ALIGN(old_size * sizeof(*rl)); + new_size = PAGE_ALIGN(new_size * sizeof(*rl)); + if (old_size == new_size) + return rl; + + new_rl = ntfs_malloc_nofs_nofail(new_size); + BUG_ON(!new_rl); + + if (likely(rl != NULL)) { + if (unlikely(old_size > new_size)) + old_size = new_size; + memcpy(new_rl, rl, old_size); + ntfs_free(rl); + } + return new_rl; +} + +/** * ntfs_are_rl_mergeable - test if two runlists can be joined together * @dst: original runlist * @src: new runlist to test for mergeability with @dst @@ -621,11 +666,8 @@ runlist_element *ntfs_runlists_merge(runlist_element *drl, if (drl[ds].lcn != LCN_RL_NOT_MAPPED) { /* Add an unmapped runlist element. */ if (!slots) { - /* FIXME/TODO: We need to have the - * extra memory already! (AIA) */ - drl = ntfs_rl_realloc(drl, ds, ds + 2); - if (!drl) - goto critical_error; + drl = ntfs_rl_realloc_nofail(drl, ds, + ds + 2); slots = 2; } ds++; @@ -640,13 +682,8 @@ runlist_element *ntfs_runlists_merge(runlist_element *drl, drl[ds].length = marker_vcn - drl[ds].vcn; /* Finally add the ENOENT terminator. */ ds++; - if (!slots) { - /* FIXME/TODO: We need to have the extra - * memory already! (AIA) */ - drl = ntfs_rl_realloc(drl, ds, ds + 1); - if (!drl) - goto critical_error; - } + if (!slots) + drl = ntfs_rl_realloc_nofail(drl, ds, ds + 1); drl[ds].vcn = marker_vcn; drl[ds].lcn = LCN_ENOENT; drl[ds].length = (s64)0; @@ -659,11 +696,6 @@ finished: ntfs_debug("Merged runlist:"); ntfs_debug_dump_runlist(drl); return drl; - -critical_error: - /* Critical error! We cannot afford to fail here. */ - ntfs_error(NULL, "Critical error! Not enough memory."); - panic("NTFS: Cannot continue."); } /** |