diff options
author | Michael Tokarev <mjt@tls.msk.ru> | 2014-12-20 08:48:44 +0000 |
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committer | Michael Tokarev <mjt@tls.msk.ru> | 2014-12-20 08:48:44 +0000 |
commit | 489bea7ee8e1dbecfa517b8415568044ab57c73a (patch) | |
tree | 44d4878d4c7da3f4908ea9a765ef9b8f9c141756 /raid5extend.c |
mdadm (3.3.2-5) unstable; urgency=medium
* use-tempnode-not-devnode.patch: change udev rules file to use
$tempnode which works both on wheezy and jessie udev, instead
of $devnode which only works in jessie. At this stage it is
better to make rules file compatible with old version instead
of adding versioned dependency. Should be removed for jessie+1.
(Closes: #770883)
* fix Closes: list in previous entry (Closes: #771852)
# imported from the archive
Diffstat (limited to 'raid5extend.c')
-rw-r--r-- | raid5extend.c | 80 |
1 files changed, 80 insertions, 0 deletions
diff --git a/raid5extend.c b/raid5extend.c new file mode 100644 index 00000000..d8e62c2c --- /dev/null +++ b/raid5extend.c @@ -0,0 +1,80 @@ + +int phys2log(int phys, int stripe, int n, int layout) +{ + /* In an 'n' disk array using 'layout', + * in stripe 'stripe', the physical disc 'phys' + * stores what logical chunk? + * -1 mean parity. + * + */ + switch(layout) { + case ALGORITHM_LEFT_ASYMMETRIC: + pd = (n-1) - (stripe % n); + if (phys < pd) + return phys; + else if (phys == pd) + return -1; + else return phys-1; + + case ALGORITHM_RIGHT_ASYMMETRIC: + pd = stripe % n; + if (phys < pd) + return phys; + else if (phys == pd) + return -1; + else return phys-1; + + case ALGORITHM_LEFT_SYMMETRIC: + pd = (n-1) - (stripe %n); + if (phys < pd) + return phys+ n-1-pd; + else if (phys == pd) + return -1; + else return phys-pd-1; + + case ALGORITHM_RIGHT_SYMMETRIC: + pd = stripe % n; + if (phys < pd) + return phys+ n-1-pd; + else if (phys == pd) + return -1; + else return phys-pd-1; + } + return -2; +} + +raid5_extend(unsigned long len, int chunksize, int layout, int n, int m, int rfds[], int wfds[]) +{ + + static char buf[4096]; + + unsigned long blocks = len/4; + unsigned int blocksperchunk= chunksize/4096; + + unsigned long b; + + for (b=0; b<blocks; b++) { + unsigned long stripe = b / blocksperchunk; + unsigned int offset = b - (stripe*blocksperchunk); + unsigned long chunk = stripe * (n-1); + int src; + for (src=0; src<n; src++) { + int dnum, snum; + if (read(rfds[src], buf, sizeof(buf)) != sizeof(buf)) { + error(); + return 0; + } + + snum = phys2log(src, stripe, n, layout); + + if (snum == -1) + continue; + chunk = stripe*(n-1)+snum; + + dstripe = chunk/(m-1); + dnum = log2phys(chunk-(stripe*(m-1)), dstripe, m, layout); + llseek(wfds[dnum], dstripe*chunksize+(offset*4096), 0); + write(wfds[dnum], buf, sizeof(buf)); + } + } +} |