|
From: Richard R. <fl...@us...> - 2005-09-15 23:42:15
|
Changes by: flatcap Update of /cvsroot/linux-ntfs/ntfsprogs/libntfs In directory sc8-pr-cvs1.sourceforge.net:/tmp/cvs-serv17705/libntfs Modified Files: runlist.c Log Message: runlist behaviour changed! please check your applications. test case 16, where a run is added beyond the end of a file, now behaves differently. the discontinuity (gap) is now filled with a "not mapped" run (before the preceding hole would have been extended). Anton's bugfix applied and tested minor code tidyups loads more comments in runlist_{insert,append,split,replace} test cases checked and updated where necessary valgrind happy Index: runlist.c =================================================================== RCS file: /cvsroot/linux-ntfs/ntfsprogs/libntfs/runlist.c,v retrieving revision 1.55 retrieving revision 1.56 diff -u -p -r1.55 -r1.56 --- runlist.c 13 Sep 2005 18:51:16 -0000 1.55 +++ runlist.c 15 Sep 2005 23:42:02 -0000 1.56 @@ -166,8 +166,8 @@ static __inline__ void __ntfs_rl_merge(r static __inline__ runlist_element *ntfs_rl_append(runlist_element *dst, int dsize, runlist_element *src, int ssize, int loc) { - BOOL right; - int magic; + BOOL right; /* Right end of @src needs merging */ + int marker; /* End of the inserted runs */ if (!dst || !src) { Dputs("Eeek. ntfs_rl_append() invoked with NULL pointer!"); @@ -181,7 +181,7 @@ static __inline__ runlist_element *ntfs_ /* Space required: @dst size + @src size, less one if we merged. */ dst = ntfs_rl_realloc(dst, dsize, dsize + ssize - right); if (!dst) - return dst; + return NULL; /* * We are guaranteed to succeed from here so can start modifying the * original runlists. @@ -191,19 +191,19 @@ static __inline__ runlist_element *ntfs_ if (right) __ntfs_rl_merge(src + ssize - 1, dst + loc + 1); - /* FIXME: What does this mean? (AIA) */ - magic = loc + ssize; + /* marker - First run after the @src runs that have been inserted */ + marker = loc + ssize + 1; /* Move the tail of @dst out of the way, then copy in @src. */ - ntfs_rl_mm(dst, magic + 1, loc + 1 + right, dsize - loc - 1 - right); + ntfs_rl_mm(dst, marker, loc + 1 + right, dsize - loc - 1 - right); ntfs_rl_mc(dst, loc + 1, src, 0, ssize); /* Adjust the size of the preceding hole. */ dst[loc].length = dst[loc + 1].vcn - dst[loc].vcn; /* We may have changed the length of the file, so fix the end marker */ - if (dst[magic + 1].lcn == LCN_ENOENT) - dst[magic + 1].vcn = dst[magic].vcn + dst[magic].length; + if (dst[marker].lcn == LCN_ENOENT) + dst[marker].vcn = dst[marker-1].vcn + dst[marker-1].length; return dst; } @@ -233,10 +233,9 @@ static __inline__ runlist_element *ntfs_ static __inline__ runlist_element *ntfs_rl_insert(runlist_element *dst, int dsize, runlist_element *src, int ssize, int loc) { - BOOL left = FALSE; - BOOL disc = FALSE; /* Discontinuity */ - BOOL hole = FALSE; /* Following a hole */ - int magic; + BOOL left = FALSE; /* Left end of @src needs merging */ + BOOL disc = FALSE; /* Discontinuity between @dst and @src */ + int marker; /* End of the inserted runs */ if (!dst || !src) { Dputs("Eeek. ntfs_rl_insert() invoked with NULL pointer!"); @@ -245,9 +244,7 @@ static __inline__ runlist_element *ntfs_ } /* disc => Discontinuity between the end of @dst and the start of @src. - * This means we might need to insert a hole. - * hole => @dst ends with a hole or an unmapped region which we can - * extend to match the discontinuity. + * This means we might need to insert a "notmapped" run. */ if (loc == 0) disc = (src[0].vcn > 0); @@ -261,16 +258,14 @@ static __inline__ runlist_element *ntfs_ merged_length += src->length; disc = (src[0].vcn > dst[loc - 1].vcn + merged_length); - if (disc) - hole = (dst[loc - 1].lcn == LCN_HOLE); } /* Space required: @dst size + @src size, less one if we merged, plus - * one if there was a discontinuity, less one for a trailing hole. + * one if there was a discontinuity. */ - dst = ntfs_rl_realloc(dst, dsize, dsize + ssize - left + disc - hole); + dst = ntfs_rl_realloc(dst, dsize, dsize + ssize - left + disc); if (!dst) - return dst; + return NULL; /* * We are guaranteed to succeed from here so can start modifying the * original runlist. @@ -279,40 +274,34 @@ static __inline__ runlist_element *ntfs_ if (left) __ntfs_rl_merge(dst + loc - 1, src); - /* FIXME: What does this mean? (AIA) */ - magic = loc + ssize - left + disc - hole; + /* + * marker - First run after the @src runs that have been inserted + * Nominally: marker = @loc + @ssize (location + number of runs in @src) + * If "left", then the first run in @src has been merged with one in @dst. + * If "disc", then @dst and @src don't meet and we need an extra run to fill the gap. + */ + marker = loc + ssize - left + disc; /* Move the tail of @dst out of the way, then copy in @src. */ - ntfs_rl_mm(dst, magic, loc, dsize - loc); - ntfs_rl_mc(dst, loc + disc - hole, src, left, ssize - left); + ntfs_rl_mm(dst, marker, loc, dsize - loc); + ntfs_rl_mc(dst, loc + disc, src, left, ssize - left); - /* Adjust the VCN of the last run ... */ - if (dst[magic].lcn <= LCN_HOLE) - dst[magic].vcn = dst[magic - 1].vcn + dst[magic - 1].length; + /* Adjust the VCN of the first run after the insertion ... */ + dst[marker].vcn = dst[marker - 1].vcn + dst[marker - 1].length; /* ... and the length. */ - if (dst[magic].lcn == LCN_HOLE || dst[magic].lcn == LCN_RL_NOT_MAPPED) - dst[magic].length = dst[magic + 1].vcn - dst[magic].vcn; + if (dst[marker].lcn == LCN_HOLE || dst[marker].lcn == LCN_RL_NOT_MAPPED) + dst[marker].length = dst[marker + 1].vcn - dst[marker].vcn; /* Writing beyond the end of the file and there's a discontinuity. */ if (disc) { - if (hole) - dst[loc - 1].length = dst[loc].vcn - dst[loc - 1].vcn; - else { - if (loc > 0) { - dst[loc].vcn = dst[loc - 1].vcn + - dst[loc - 1].length; - dst[loc].length = dst[loc + 1].vcn - - dst[loc].vcn; - } else { - dst[loc].vcn = 0; - dst[loc].length = dst[loc + 1].vcn; - } - dst[loc].lcn = LCN_RL_NOT_MAPPED; + if (loc > 0) { + dst[loc].vcn = dst[loc - 1].vcn + dst[loc - 1].length; + dst[loc].length = dst[loc + 1].vcn - dst[loc].vcn; + } else { + dst[loc].vcn = 0; + dst[loc].length = dst[loc + 1].vcn; } - - if (dst[magic].lcn == LCN_ENOENT) - dst[magic].vcn = dst[magic - 1].vcn + - dst[magic - 1].length; + dst[loc].lcn = LCN_RL_NOT_MAPPED; } return dst; } @@ -341,9 +330,9 @@ static __inline__ runlist_element *ntfs_ static __inline__ runlist_element *ntfs_rl_replace(runlist_element *dst, int dsize, runlist_element *src, int ssize, int loc) { - BOOL left = FALSE; - BOOL right; - int magic; + BOOL left = FALSE; /* Left end of @src needs merging */ + BOOL right; /* Right end of @src needs merging */ + int marker; /* End of the inserted runs */ if (!dst || !src) { Dputs("Eeek. ntfs_rl_replace() invoked with NULL pointer!"); @@ -361,7 +350,7 @@ static __inline__ runlist_element *ntfs_ */ dst = ntfs_rl_realloc(dst, dsize, dsize + ssize - left - right); if (!dst) - return dst; + return NULL; /* * We are guaranteed to succeed from here so can start modifying the * original runlists. @@ -371,16 +360,21 @@ static __inline__ runlist_element *ntfs_ if (left) __ntfs_rl_merge(dst + loc - 1, src); - /* FIXME: What does this mean? (AIA) */ - magic = loc + ssize - left; + /* + * marker - First run after the @src runs that have been inserted + * Nominally: marker = @loc + @ssize (location + number of runs in @src) + * If "left", then the first run in @src has been merged with one in @dst. + */ + marker = loc + ssize - left; /* Move the tail of @dst out of the way, then copy in @src. */ - ntfs_rl_mm(dst, magic, loc + right + 1, dsize - loc - right - 1); + ntfs_rl_mm(dst, marker, loc + right + 1, dsize - loc - right - 1); ntfs_rl_mc(dst, loc, src, left, ssize - left); /* We may have changed the length of the file, so fix the end marker */ - if (((dsize - loc - right - 1) > 0) && (dst[magic].lcn == LCN_ENOENT)) - dst[magic].vcn = dst[magic - 1].vcn + dst[magic - 1].length; + if (((dsize - loc - right - 1) > 0) && (dst[marker].lcn == LCN_ENOENT)) + dst[marker].vcn = dst[marker - 1].vcn + dst[marker - 1].length; + return dst; } @@ -498,6 +492,7 @@ runlist_element *ntfs_runlists_merge(run /* Scan to the end of the source runlist. */ for (dend = 0; drl[dend].length; dend++) ; + dend++; drl = ntfs_rl_realloc(drl, dend, dend + 1); if (!drl) return drl; @@ -574,7 +569,7 @@ runlist_element *ntfs_runlists_merge(run (srl[send - 1].vcn + srl[send - 1].length))); /* Or we'll lose an end marker */ - if (start && finish && (drl[dins].length == 0)) + if (finish && !drl[dins].length) ss++; if (marker && (drl[dins].vcn + drl[dins].length > srl[send - 1].vcn)) finish = FALSE; @@ -1732,11 +1727,9 @@ static void test_rl_dump_runlist (const if (ind > -LCN_ENOENT - 1) ind = 3; - //printf("%8llx %8s %8llx\n", printf("%8lld %8s %8lld\n", rl->vcn, lcn_str[ind], rl->length); } else - //printf("%8llx %8llx %8llx\n", printf("%8lld %8lld %8lld\n", rl->vcn, rl->lcn, rl->length); if (!rl->length) @@ -1834,7 +1827,6 @@ static void test_rl_pure_test (int test, res = test_rl_runlists_merge (dst, src); free (res); - test = 0; } /** |
