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Diffstat (limited to 'libparted/cs/geom.c')
-rw-r--r-- | libparted/cs/geom.c | 487 |
1 files changed, 487 insertions, 0 deletions
diff --git a/libparted/cs/geom.c b/libparted/cs/geom.c new file mode 100644 index 0000000..99280ac --- /dev/null +++ b/libparted/cs/geom.c @@ -0,0 +1,487 @@ +/* + libparted - a library for manipulating disk partitions + Copyright (C) 1999-2000, 2005, 2007-2014, 2019-2023 Free Software + Foundation, Inc. + + This program is free software; you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation; either version 3 of the License, or + (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program. If not, see <http://www.gnu.org/licenses/>. +*/ + +/** \file geom.c */ + + +/** + * \addtogroup PedGeometry + * + * \brief PedGeometry represents a continuous region on a device. All addressing + * through a PedGeometry object is in terms of the start of the continuous + * region. + * + * The following conditions are always true on a PedGeometry object manipulated + * with the GNU Parted API: + * + * - <tt>start + length - 1 == end</tt> + * - <tt>length > 0</tt> + * - <tt>start >= 0</tt> + * - <tt>end < dev->length</tt> + * + * @{ + */ + +#include <config.h> + +#include <parted/parted.h> +#include <parted/debug.h> + +#if ENABLE_NLS +# include <libintl.h> +# define _(String) dgettext (PACKAGE, String) +#else +# define _(String) (String) +#endif /* ENABLE_NLS */ + +/** + * Initialize the previously allocated PedGeometry \p geom. + */ +int +ped_geometry_init (PedGeometry* geom, const PedDevice* dev, + PedSector start, PedSector length) +{ + PED_ASSERT (geom != NULL); + PED_ASSERT (dev != NULL); + + geom->dev = (PedDevice*) dev; + return ped_geometry_set (geom, start, length); +} + +/** + * Create a new PedGeometry object on \p disk, starting at \p start with a + * size of \p length sectors. + * + * \return NULL on failure. + */ +PedGeometry* +ped_geometry_new (const PedDevice* dev, PedSector start, PedSector length) +{ + PedGeometry* geom; + + PED_ASSERT (dev != NULL); + + geom = (PedGeometry*) ped_malloc (sizeof (PedGeometry)); + if (!geom) + goto error; + if (!ped_geometry_init (geom, dev, start, length)) + goto error_free_geom; + return geom; + +error_free_geom: + free (geom); +error: + return NULL; +} + +/** + * Duplicate a PedGeometry object. + * + * This function constructs a PedGeometry object that is an identical but + * independent copy of \p geom. Both the input, \p geom, and the output + * should be destroyed with ped_geometry_destroy() when they are no + * longer needed. + * + * \return NULL on failure. + */ +PedGeometry* +ped_geometry_duplicate (const PedGeometry* geom) +{ + PED_ASSERT (geom != NULL); + return ped_geometry_new (geom->dev, geom->start, geom->length); +} + +/** + * Return a PedGeometry object that refers to the intersection of + * \p a and \p b. + * + * This function constructs a PedGeometry object that describes the + * region that is common to both a and b. If there is no such common + * region, it returns NULL. (This situation is not treated as an + * error by much of GNU Parted.) + */ +PedGeometry* +ped_geometry_intersect (const PedGeometry* a, const PedGeometry* b) +{ + PedSector start; + PedSector end; + + if (!a || !b || a->dev != b->dev) + return NULL; + + start = PED_MAX (a->start, b->start); + end = PED_MIN (a->end, b->end); + if (start > end) + return NULL; + + return ped_geometry_new (a->dev, start, end - start + 1); +} + +/** + * Destroy a PedGeometry object. + */ +void +ped_geometry_destroy (PedGeometry* geom) +{ + PED_ASSERT (geom != NULL); + + free (geom); +} + +/** + * Assign a new \p start, \p end (implicitly) and \p length to \p geom. + * + * \p geom->end is calculated from \p start and \p length. + */ +int +ped_geometry_set (PedGeometry* geom, PedSector start, PedSector length) +{ + PED_ASSERT (geom != NULL); + PED_ASSERT (geom->dev != NULL); + PED_ASSERT (start >= 0); + + if (length < 1) { + ped_exception_throw ( + PED_EXCEPTION_ERROR, + PED_EXCEPTION_CANCEL, + _("Can't have the end before the start!" + " (start sector=%jd length=%jd)"), start, length); + return 0; + } + + geom->start = start; + geom->length = length; + geom->end = start + length - 1; + + return 1; +} + +/** + * Assign a new start to \p geom without changing \p geom->end. + * + * \p geom->length is updated accordingly. + */ +int +ped_geometry_set_start (PedGeometry* geom, PedSector start) +{ + return ped_geometry_set (geom, start, geom->end - start + 1); +} + +/** + * Assign a new end to \p geom without changing \p geom->start. + * + * \p geom->length is updated accordingly. + */ +int +ped_geometry_set_end (PedGeometry* geom, PedSector end) +{ + return ped_geometry_set (geom, geom->start, end - geom->start + 1); +} +/** + * Test if \p a overlaps with \p b. + * + * That is, they lie on the same physical device, and they share + * the same physical region at least partially. + * + * \return 1 if \p a and \p b overlap. + */ +int +ped_geometry_test_overlap (const PedGeometry* a, const PedGeometry* b) +{ + PED_ASSERT (a != NULL); + PED_ASSERT (b != NULL); + + if (a->dev != b->dev) + return 0; + + if (a->start < b->start) + return a->end >= b->start; + else + return b->end >= a->start; +} + +/** + * Tests if \p b lies completely within \p a. That is, they lie on the same + * physical device, and all of the \p b's region is contained inside + * \p a's. + * + * \return 1 if the region \p b describes is contained entirely inside \p a +*/ +int +ped_geometry_test_inside (const PedGeometry* a, const PedGeometry* b) +{ + PED_ASSERT (a != NULL); + PED_ASSERT (b != NULL); + + if (a->dev != b->dev) + return 0; + + return b->start >= a->start && b->end <= a->end; +} + +/** + * Tests if \a a and \p b refer to the same physical region. + * + * \return 1 if \p a and \p b describe the same regions + * + */ +int +ped_geometry_test_equal (const PedGeometry* a, const PedGeometry* b) +{ + PED_ASSERT (a != NULL); + PED_ASSERT (b != NULL); + + return a->dev == b->dev + && a->start == b->start + && a->end == b->end; +} + +/** + * Tests if \p sector is inside \p geom. + * + * \return 1 if sector lies within the \p region that \p geom describes + */ +int +ped_geometry_test_sector_inside (const PedGeometry* geom, PedSector sector) +{ + PED_ASSERT (geom != NULL); + + return sector >= geom->start && sector <= geom->end; +} + +/** + * Reads data from the region represented by \p geom. \p offset is the + * location from within the region, not from the start of the disk. + * \p count sectors are read into \p buffer. + * This is essentially equivalent to: + * \code + * ped_device_read (geom->disk->dev, buffer, geom->start + offset, count) + * \endcode + * + * \throws PED_EXCEPTION_ERROR when attempting to read sectors outside of + * partition + * + * \return 0 on failure + */ +int +ped_geometry_read (const PedGeometry* geom, void* buffer, PedSector offset, + PedSector count) +{ + PedSector real_start; + + PED_ASSERT (geom != NULL); + PED_ASSERT (buffer != NULL); + PED_ASSERT (offset >= 0); + PED_ASSERT (count >= 0); + + real_start = geom->start + offset; + + if (real_start + count - 1 > geom->end) + return 0; + + if (!ped_device_read (geom->dev, buffer, real_start, count)) + return 0; + return 1; +} + +/* Like ped_device_read, but read into malloc'd storage. */ +int +ped_geometry_read_alloc (const PedGeometry* geom, void** buffer, + PedSector offset, PedSector count) +{ + char *buf = ped_malloc (count * geom->dev->sector_size); + if (buf == NULL) + return 0; + int ok = ped_geometry_read (geom, buf, offset, count); + if (!ok) { + free (buf); + buf = NULL; + } + + *buffer = buf; + return ok; +} + +/** + * Flushes the cache on \p geom. + * + * This function flushes all write-behind caches that might be holding + * writes made by ped_geometry_write() to \p geom. It is slow, because + * it guarantees cache coherency among all relevant caches. + * + * \return 0 on failure + */ +int +ped_geometry_sync (PedGeometry* geom) +{ + PED_ASSERT (geom != NULL); + return ped_device_sync (geom->dev); +} + +/** + * Flushes the cache on \p geom. + * + * This function flushes all write-behind caches that might be holding writes + * made by ped_geometry_write() to \p geom. It does NOT ensure cache coherency + * with other caches that cache data in the region described by \p geom. + * If you need cache coherency, use ped_geometry_sync() instead. + * + * \return 0 on failure + */ +int +ped_geometry_sync_fast (PedGeometry* geom) +{ + PED_ASSERT (geom != NULL); + return ped_device_sync_fast (geom->dev); +} + +/** + * Writes data into the region represented by \p geom. \p offset is the + * location from within the region, not from the start of the disk. + * \p count sectors are written. + * + * \return 0 on failure + */ +int +ped_geometry_write (PedGeometry* geom, const void* buffer, PedSector offset, + PedSector count) +{ + int exception_status; + PedSector real_start; + + PED_ASSERT (geom != NULL); + PED_ASSERT (buffer != NULL); + PED_ASSERT (offset >= 0); + PED_ASSERT (count >= 0); + + real_start = geom->start + offset; + + if (real_start + count - 1 > geom->end) { + exception_status = ped_exception_throw ( + PED_EXCEPTION_ERROR, + PED_EXCEPTION_IGNORE_CANCEL, + _("Attempt to write sectors %ld-%ld outside of " + "partition on %s."), + (long) offset, (long) (offset + count - 1), + geom->dev->path); + return exception_status == PED_EXCEPTION_IGNORE; + } + + if (!ped_device_write (geom->dev, buffer, real_start, count)) + return 0; + return 1; +} + +/** + * Checks for physical disk errors. \todo use ped_device_check() + * + * Checks a region for physical defects on \p geom. \p buffer is used + * for temporary storage for ped_geometry_check(), and has an undefined + * value. \p buffer is \p buffer_size sectors long. + * The region checked starts at \p offset sectors inside the + * region represented by \p geom, and is \p count sectors long. + * \p granularity specificies how sectors should be grouped + * together. The first bad sector to be returned will always be in + * the form: + * <tt>offset + n * granularity</tt> + * + * \return the first bad sector, or 0 if there were no physical errors + */ +PedSector +ped_geometry_check (PedGeometry* geom, void* buffer, PedSector buffer_size, + PedSector offset, PedSector granularity, PedSector count, + PedTimer* timer) +{ + PedSector group; + PedSector i; + PedSector read_len; + + PED_ASSERT (geom != NULL); + PED_ASSERT (buffer != NULL); + + ped_timer_reset (timer); + ped_timer_set_state_name (timer, _("checking for bad blocks")); + +retry: + ped_exception_fetch_all(); + for (group = offset; group < offset + count; group += buffer_size) { + ped_timer_update (timer, 1.0 * (group - offset) / count); + read_len = PED_MIN (buffer_size, offset + count - group); + if (!ped_geometry_read (geom, buffer, group, read_len)) + goto found_error; + } + ped_exception_leave_all(); + ped_timer_update (timer, 1.0); + return 0; + +found_error: + ped_exception_catch(); + for (i = group; i + granularity < group + count; i += granularity) { + if (!ped_geometry_read (geom, buffer, i, granularity)) { + ped_exception_catch(); + ped_exception_leave_all(); + return i; + } + } + ped_exception_leave_all(); + goto retry; /* weird: failure on group read, but not individually */ +} + +/** + * This function takes a \p sector inside the region described by src, and + * returns that sector's address inside dst. This means that + * + * \code + * ped_geometry_read (dst, buf, ped_geometry_map(dst, src, sector), 1) + * \endcode + * + * does the same thing as + * + * \code + * ped_geometry_read (src, buf, sector, 1) + * \endcode + * + * Clearly, this will only work if \p src and \p dst overlap. + * + * \return -1 if \p sector is not within \p dst's space, + * or \p sector's address inside \p dst + * + */ +PedSector +ped_geometry_map (const PedGeometry* dst, const PedGeometry* src, + PedSector sector) +{ + PedSector result; + + PED_ASSERT (dst != NULL); + PED_ASSERT (src != NULL); + + if (!ped_geometry_test_sector_inside (src, sector)) + return -1; + if (dst->dev != src->dev) + return -1; + + result = src->start + sector - dst->start; + if (result < 0 || result > dst->length) + return -1; + + return result; +} + +/** @} */ |