libceph: eliminate overflows in ceph_calc_file_object_mapping()
bl, stripeno and objsetno should be u64 -- otherwise large enough files get corrupted. How large depends on file layout: - 4M-objects layout (default): any file over 16P - 64K-objects layout (smallest possible object size): any file over 512T Only CephFS is affected, rbd doesn't use ceph_calc_file_object_mapping() yet. Fortunately, CephFS has a max_file_size configurable, the default for which is way below both of the above numbers. Reimplement the logic from scratch with no layout validation -- it's done on the MDS side. Signed-off-by: Ilya Dryomov <idryomov@gmail.com> Reviewed-by: Alex Elder <elder@linaro.org>
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@ -2141,72 +2141,40 @@ bool ceph_osds_changed(const struct ceph_osds *old_acting,
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}
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}
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/*
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/*
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* calculate file layout from given offset, length.
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* Map a file extent to a stripe unit within an object.
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* fill in correct oid, logical length, and object extent
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* Fill in objno, offset into object, and object extent length (i.e. the
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* offset, length.
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* number of bytes mapped, less than or equal to @l->stripe_unit).
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*
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*
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* for now, we write only a single su, until we can
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* Example for stripe_count = 3, stripes_per_object = 4:
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* pass a stride back to the caller.
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*
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* blockno | 0 3 6 9 | 1 4 7 10 | 2 5 8 11 | 12 15 18 21 | 13 16 19
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* stripeno | 0 1 2 3 | 0 1 2 3 | 0 1 2 3 | 4 5 6 7 | 4 5 6
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* stripepos | 0 | 1 | 2 | 0 | 1
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* objno | 0 | 1 | 2 | 3 | 4
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* objsetno | 0 | 1
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*/
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*/
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int ceph_calc_file_object_mapping(struct ceph_file_layout *layout,
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int ceph_calc_file_object_mapping(struct ceph_file_layout *l,
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u64 off, u64 len,
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u64 off, u64 len,
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u64 *ono,
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u64 *objno, u64 *objoff, u64 *xlen)
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u64 *oxoff, u64 *oxlen)
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{
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{
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u32 osize = layout->object_size;
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u32 stripes_per_object = l->object_size / l->stripe_unit;
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u32 su = layout->stripe_unit;
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u64 blockno; /* which su in the file (i.e. globally) */
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u32 sc = layout->stripe_count;
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u32 blockoff; /* offset into su */
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u32 bl, stripeno, stripepos, objsetno;
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u64 stripeno; /* which stripe */
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u32 su_per_object;
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u32 stripepos; /* which su in the stripe,
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u64 t, su_offset;
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which object in the object set */
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u64 objsetno; /* which object set */
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u32 objsetpos; /* which stripe in the object set */
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dout("mapping %llu~%llu osize %u fl_su %u\n", off, len,
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blockno = div_u64_rem(off, l->stripe_unit, &blockoff);
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osize, su);
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stripeno = div_u64_rem(blockno, l->stripe_count, &stripepos);
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if (su == 0 || sc == 0)
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objsetno = div_u64_rem(stripeno, stripes_per_object, &objsetpos);
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goto invalid;
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su_per_object = osize / su;
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if (su_per_object == 0)
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goto invalid;
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dout("osize %u / su %u = su_per_object %u\n", osize, su,
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su_per_object);
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if ((su & ~PAGE_MASK) != 0)
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*objno = objsetno * l->stripe_count + stripepos;
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goto invalid;
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*objoff = objsetpos * l->stripe_unit + blockoff;
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*xlen = min_t(u64, len, l->stripe_unit - blockoff);
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/* bl = *off / su; */
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t = off;
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do_div(t, su);
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bl = t;
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dout("off %llu / su %u = bl %u\n", off, su, bl);
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stripeno = bl / sc;
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stripepos = bl % sc;
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objsetno = stripeno / su_per_object;
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*ono = objsetno * sc + stripepos;
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dout("objset %u * sc %u = ono %u\n", objsetno, sc, (unsigned int)*ono);
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/* *oxoff = *off % layout->fl_stripe_unit; # offset in su */
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t = off;
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su_offset = do_div(t, su);
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*oxoff = su_offset + (stripeno % su_per_object) * su;
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/*
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* Calculate the length of the extent being written to the selected
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* object. This is the minimum of the full length requested (len) or
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* the remainder of the current stripe being written to.
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*/
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*oxlen = min_t(u64, len, su - su_offset);
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dout(" obj extent %llu~%llu\n", *oxoff, *oxlen);
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return 0;
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return 0;
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invalid:
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dout(" invalid layout\n");
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*ono = 0;
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*oxoff = 0;
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*oxlen = 0;
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return -EINVAL;
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}
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}
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EXPORT_SYMBOL(ceph_calc_file_object_mapping);
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EXPORT_SYMBOL(ceph_calc_file_object_mapping);
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