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2017-11-17block: Deprecate bdrv_set_read_only() and usersKevin Wolf
bdrv_set_read_only() is used by some block drivers to override the read-only option given by the user. This is not how read-only images generally work in QEMU: Instead of second guessing what the user really meant (which currently includes making an image read-only even if the user didn't only use the default, but explicitly said read-only=off), we should error out if we can't provide what the user requested. This adds deprecation warnings to all callers of bdrv_set_read_only() so that the behaviour can be corrected after the usual deprecation period. Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2017-08-31dmg: use DIV_ROUND_UPMarc-André Lureau
I used the clang-tidy qemu-round check to generate the fix: https://github.com/elmarco/clang-tools-extra Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Richard Henderson <rth@twiddle.net>
2017-04-24block: do not set BDS read_only if copy_on_read enabledJeff Cody
A few block drivers will set the BDS read_only flag from their .bdrv_open() function. This means the bs->read_only flag could be set after we enable copy_on_read, as the BDRV_O_COPY_ON_READ flag check occurs prior to the call to bdrv->bdrv_open(). This adds an error return to bdrv_set_read_only(), and an error will be return if we try to set the BDS to read_only while copy_on_read is enabled. This patch also changes the behavior of vvfat. Before, vvfat could override the drive 'readonly' flag with its own, internal 'rw' flag. For instance, this -drive parameter would result in a writable image: "-drive format=vvfat,dir=/tmp/vvfat,rw,if=virtio,readonly=on" This is not correct. Now, attempting to use the above -drive parameter will result in an error (i.e., 'rw' is incompatible with 'readonly=on'). Signed-off-by: Jeff Cody <jcody@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: John Snow <jsnow@redhat.com> Message-id: 0c5b4c1cc2c651471b131f21376dfd5ea24d2196.1491597120.git.jcody@redhat.com
2017-04-24block: add bdrv_set_read_only() helper functionJeff Cody
We have a helper wrapper for checking for the BDS read_only flag, add a helper wrapper to set the read_only flag as well. Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Jeff Cody <jcody@redhat.com> Reviewed-by: John Snow <jsnow@redhat.com> Message-id: 9b18972d05f5fa2ac16c014f0af98d680553048d.1491597120.git.jcody@redhat.com
2017-02-28block: Request child permissions in format driversKevin Wolf
This makes use of the .bdrv_child_perm() implementation for formats that we just added. All format drivers expose the permissions they actually need nows, so that they can be set accordingly and updated when parents are attached or detached. The only format not included here is raw, which was already converted with the other filter drivers. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Acked-by: Fam Zheng <famz@redhat.com>
2017-02-24block: Attach bs->file only during .bdrv_open()Kevin Wolf
The way that attaching bs->file worked was a bit unusual in that it was the only child that would be attached to a node which is not opened yet. Because of this, the block layer couldn't know yet which permissions the driver would eventually need. This patch moves the point where bs->file is attached to the beginning of the individual .bdrv_open() implementations, so drivers already know what they are going to do with the child. This is also more consistent with how driver-specific children work. For a moment, bdrv_open() gets its own BdrvChild to perform image probing, but instead of directly assigning this BdrvChild to the BDS, it becomes a temporary one and the node name is passed as an option to the drivers, so that they can simply use bdrv_open_child() to create another reference for their own use. This duplicated child for (the not opened yet) bs is not the final state, a follow-up patch will change the image probing code to use a BlockBackend, which is completely independent of bs. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com>
2016-10-07dmg: Move libbz2 code to dmg-bz2.soFam Zheng
dmg.o was moved to block-obj-m in 5505e8b76 to become a separate module, so that its reference to libbz2, since 6b383c08c, doesn't add an extra library to the main executable. Until recently, commit 06e60f70a (blockdev: Add dynamic module loading for block drivers) moved it back to block-obj-y to simplify the design of dynamic loading of block modules. But we don't want to lose the feature of less library dependency on the main executable. The solution here is to move only the bz2 related code to a separate DSO file, and load it when dmg_open is called. dmg_probe doesn't depend on bz2 support to work, and is the only code in this file which can run before dmg_open. While we are at it, fix the unhelpful cast of last argument passed to dmg_uncompress_bz2. Signed-off-by: Fam Zheng <famz@redhat.com> Message-id: 1473043845-13197-4-git-send-email-famz@redhat.com Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Max Reitz <mreitz@redhat.com>
2016-07-05block: Convert bdrv_pread(v) to BdrvChildKevin Wolf
Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
2016-07-05block: Use bool as appropriate for BDS membersEric Blake
Using int for values that are only used as booleans is confusing. While at it, rearrange a couple of members so that all the bools are contiguous. Signed-off-by: Eric Blake <eblake@redhat.com> Reviewed-by: Fam Zheng <famz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2016-07-05block: Move request_alignment into BlockLimitEric Blake
It makes more sense to have ALL block size limit constraints in the same struct. Improve the documentation while at it. Simplify a couple of conditionals, now that we have audited and documented that request_alignment is always non-zero. Signed-off-by: Eric Blake <eblake@redhat.com> Reviewed-by: Fam Zheng <famz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2016-07-05block: Set request_alignment during .bdrv_refresh_limits()Eric Blake
We want to eventually stick request_alignment alongside other BlockLimits, but first, we must ensure it is populated at the same time as all other limits, rather than being a special case that is set only when a block is first opened. Add a .bdrv_refresh_limits() to all four of our legacy devices that will always be sector-only (bochs, cloop, dmg, vvfat), in spite of their recent conversion to expose a byte interface. Signed-off-by: Eric Blake <eblake@redhat.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Fam Zheng <famz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2016-06-07all: Remove unnecessary glib.h includesPeter Maydell
Remove glib.h includes, as it is provided by osdep.h. This commit was created with scripts/clean-includes. Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Reviewed-by: Eric Blake <eblake@redhat.com> Tested-by: Eric Blake <eblake@redhat.com> Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
2016-05-12dmg: Implement .bdrv_co_preadv() interfaceKevin Wolf
This implements .bdrv_co_preadv() for the cloop block driver. While updating the error paths, change -1 to a valid -errno code. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Fam Zheng <famz@redhat.com>
2016-03-22include/qemu/osdep.h: Don't include qapi/error.hMarkus Armbruster
Commit 57cb38b included qapi/error.h into qemu/osdep.h to get the Error typedef. Since then, we've moved to include qemu/osdep.h everywhere. Its file comment explains: "To avoid getting into possible circular include dependencies, this file should not include any other QEMU headers, with the exceptions of config-host.h, compiler.h, os-posix.h and os-win32.h, all of which are doing a similar job to this file and are under similar constraints." qapi/error.h doesn't do a similar job, and it doesn't adhere to similar constraints: it includes qapi-types.h. That's in excess of 100KiB of crap most .c files don't actually need. Add the typedef to qemu/typedefs.h, and include that instead of qapi/error.h. Include qapi/error.h in .c files that need it and don't get it now. Include qapi-types.h in qom/object.h for uint16List. Update scripts/clean-includes accordingly. Update it further to match reality: replace config.h by config-target.h, add sysemu/os-posix.h, sysemu/os-win32.h. Update the list of includes in the qemu/osdep.h comment quoted above similarly. This reduces the number of objects depending on qapi/error.h from "all of them" to less than a third. Unfortunately, the number depending on qapi-types.h shrinks only a little. More work is needed for that one. Signed-off-by: Markus Armbruster <armbru@redhat.com> [Fix compilation without the spice devel packages. - Paolo] Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-01-20block: Clean up includesPeter Maydell
Clean up includes so that osdep.h is included first and headers which it implies are not included manually. This commit was created with scripts/clean-includes. Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2015-10-16block: Convert bs->file to BdrvChildKevin Wolf
This patch removes the temporary duplication between bs->file and bs->file_child by converting everything to BdrvChild. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Alberto Garcia <berto@igalia.com> Reviewed-by: Fam Zheng <famz@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
2015-06-22qerror: Move #include out of qerror.hMarkus Armbruster
Signed-off-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Luiz Capitulino <lcapitulino@redhat.com>
2015-02-06block/dmg: improve zeroes handlingPeter Wu
Disk images may contain large all-zeroes gaps (1.66k sectors or 812 MiB is seen in the real world). These blocks (type 2) do not need to be extracted into a temporary buffer, there is no need to allocate memory for these blocks nor to check its length. (For the test image, the maximum uncompressed size is 1054371 bytes, probably for a bzip2-compressed block.) Signed-off-by: Peter Wu <peter@lekensteyn.nl> Reviewed-by: John Snow <jsnow@redhat.com> Message-id: 1420566495-13284-13-git-send-email-peter@lekensteyn.nl Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2015-02-06block/dmg: support bzip2 block entry typesPeter Wu
This patch adds support for bzip2-compressed block entries as introduced with OS X 10.4 (source: https://en.wikipedia.org/wiki/Apple_Disk_Image). It was tested against a 5.2G "OS X Yosemite" installation image which stores the BLXX block in the XML property list (instead of resource forks) and has over 5k chunks. New configure entries are added (--enable-bzip2 / --disable-bzip2) to control inclusion of bzip2 functionality (which requires linking against libbz2). The help message suggests that this option is needed for DMG files, but the tests are generic enough that other parts of QEMU can use bzip2 if needed. The identifiers are based on http://newosxbook.com/DMG.html. The decompression routines are based on the zlib case, but as there is no way to reset the decompression state (unlike zlib), memory is allocated and deallocated for every decompression. This should not be problematic as the decompression takes most of the time and as blocks are typically about/over 1 MiB in size, only one allocation is done every 2000 sectors. Signed-off-by: Peter Wu <peter@lekensteyn.nl> Reviewed-by: John Snow <jsnow@redhat.com> Acked-by: Paolo Bonzini <pbonzini@redhat.com> Message-id: 1420566495-13284-12-git-send-email-peter@lekensteyn.nl Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2015-02-06block/dmg: factor out block type checkPeter Wu
In preparation for adding bzip2 support, split the type check into a separate function. Make all offsets relative to the begin of a chunk such that it is easier to recognize the position without having to add up all offsets. Some comments are added to describe the fields. There is no functional change. Signed-off-by: Peter Wu <peter@lekensteyn.nl> Reviewed-by: John Snow <jsnow@redhat.com> Message-id: 1420566495-13284-11-git-send-email-peter@lekensteyn.nl Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2015-02-06block/dmg: use SectorNumber from BLKX headerPeter Wu
Previously the sector table parsing relied on the previous offset of the DMG file. Now it uses the sector number from the BLKX header (see http://newosxbook.com/DMG.html). The implementation of dmg2img (from vu1tur) does not base the output sector on the location of the terminator (0xffffffff) either so it should be safe to drop this dependency on the previous state. (It makes somehow makes sense, a terminator should halt further processing of a block and is perhaps used to preallocate some space.) Signed-off-by: Peter Wu <peter@lekensteyn.nl> Reviewed-by: John Snow <jsnow@redhat.com> Message-id: 1420566495-13284-10-git-send-email-peter@lekensteyn.nl Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2015-02-06block/dmg: fix sector data offset calculationPeter Wu
This patch addresses two issues: - The data fork offset was not taken into account, resulting in failure to read an InstallESD.dmg file (5164763151 bytes) which had a non-zero DataForkOffset field. - The offset of the previous block ("partition") was unconditionally added to the current block because older files would start the input offset of a new block at zero. Newer files (including vlc-2.1.5.dmg, tuxpaint-0.9.15-macosx.dmg and OS X Yosemite [MAS].dmg) failed in reads because these files have chunk offsets, relative to the begin of a data fork. Now the data offset of the mish is taken into account. While we could check that the data_offset is within the data fork, let's not do that here as it would only result in parse failures on invalid files (rather than gracefully handling such bad files). dmg_read will error out if the offset is incorrect. Signed-off-by: Peter Wu <peter@lekensteyn.nl> Reviewed-by: John Snow <jsnow@redhat.com> Message-id: 1420566495-13284-9-git-send-email-peter@lekensteyn.nl Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2015-02-06block/dmg: set virtual size to a non-zero valuePeter Wu
Right now the virtual size is always reported as zero which makes it impossible to convert between formats. After this patch, the number of sectors will be read from the trailer ("koly" block). To verify the behavior, the output of `dmg2img foo.dmg foo.img` was compared against `qemu-img convert -f dmg -O raw foo.dmg foo.raw`. The tests showed that the file contents are exactly the same, except that QEMU creates a slightly larger file (it matches the total sectors count). Signed-off-by: Peter Wu <peter@lekensteyn.nl> Reviewed-by: John Snow <jsnow@redhat.com> Message-id: 1420566495-13284-8-git-send-email-peter@lekensteyn.nl Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2015-02-06block/dmg: process XML plistsPeter Wu
The format is simple enough to avoid using a full-blown XML parser. It assumes that all BLKX items begin with the "mish" magic word, therefore it is not a problem if other values get matched which are not a BLKX block. The offsets are based on the description at http://newosxbook.com/DMG.html For compatibility with glib 2.12, use g_base64_decode (which additionally requires an extra buffer allocation) instead of g_base64_decode_inplace (which is only available since glib 2.20). Signed-off-by: Peter Wu <peter@lekensteyn.nl> Reviewed-by: John Snow <jsnow@redhat.com> Message-id: 1420566495-13284-7-git-send-email-peter@lekensteyn.nl Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2015-02-06block/dmg: validate chunk size to avoid overflowPeter Wu
Previously the chunk size was not checked, allowing for a large memory allocation. This patch checks whether the chunks size is within the resource fork length, and whether the resource fork is below the trailer of the dmg file. Signed-off-by: Peter Wu <peter@lekensteyn.nl> Reviewed-by: John Snow <jsnow@redhat.com> Message-id: 1420566495-13284-6-git-send-email-peter@lekensteyn.nl Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2015-02-06block/dmg: process a buffer instead of reading intsPeter Wu
As the decoded plist XML is not a pointer in the file, dmg_read_mish_block must be able to process a buffer instead of a file pointer. Since the full buffer must be processed, let's change the return value again to just a success flag. Signed-off-by: Peter Wu <peter@lekensteyn.nl> Reviewed-by: John Snow <jsnow@redhat.com> Message-id: 1420566495-13284-5-git-send-email-peter@lekensteyn.nl Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2015-02-06block/dmg: extract processing of resource forksPeter Wu
Besides the offset, also read the resource length. This length is now used in the extracted function to verify the end of the resource fork against "count" from the resource fork. Instead of relying on the value of offset to conclude whether the resource fork is available or not (info_begin==0), check the rsrc_fork_length instead. This would allow a dmg file to begin with a resource fork. This seemingly unnecessary restriction was found while trying to craft a DMG file by hand. Other changes: - Do not require resource data offset to be 0x100 (but check that it is within bounds though). - Further improve boundary checking (resource data must be within the resource fork). - Use correct value for resource data length (spotted by John Snow) - Consider the resource data offset when determining info_end. This fixes an EINVAL on the tuxpaint dmg example. The resource fork format is documented at https://developer.apple.com/legacy/library/documentation/mac/pdf/MoreMacintoshToolbox.pdf#page=151 Signed-off-by: Peter Wu <peter@lekensteyn.nl> Reviewed-by: John Snow <jsnow@redhat.com> Message-id: 1420566495-13284-4-git-send-email-peter@lekensteyn.nl Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2015-02-06block/dmg: extract mish block decoding functionalityPeter Wu
Extract the mish block decoder such that this can be used for other formats in the future. A new DmgHeaderState struct is introduced to share state while decoding. The code is kept unchanged as much as possible, a "fail" label is added for example where a simple return would probably do. In dmg_open, the variable "tmp" is renamed to "rsrc_data_offset" for clarity and comments have been added explaining various data. Note that this patch has one subtle difference with the previous version which should not affect functionality. In the previous code, the end of a resource was inferred from the mish block (the offsets would be increased by the fields). In this patch, the resource length is used instead to avoid the need to rely on the previous offsets. Signed-off-by: Peter Wu <peter@lekensteyn.nl> Reviewed-by: John Snow <jsnow@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Message-id: 1420566495-13284-3-git-send-email-peter@lekensteyn.nl Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2015-02-06block/dmg: properly detect the UDIF trailerPeter Wu
DMG files have a variable length with a UDIF trailer at the end of a file. This UDIF trailer is essential as it describes the contents of the image. At the moment however, the start of this trailer is almost always incorrect as bdrv_getlength() returns a multiple of the block size (rounded up). This results in a failure to recognize DMG files, resulting in Invalid argument (EINVAL) errors. As there is no API to retrieve the real file size, look for the magic header in the last two sectors to find the start of this 512-byte UDIF trailer (the "koly" block). The resource fork offset ("info_begin") has its offset adjusted as the initial value of offset does not mean "end of file" anymore, but "begin of UDIF trailer". [Replaced error_set(errp, ERROR_CLASS_GENERIC_ERROR, ...) with error_setg(errp, ...) as discussed with Peter. --Stefan] Signed-off-by: Peter Wu <peter@lekensteyn.nl> Reviewed-by: John Snow <jsnow@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Message-id: 1420566495-13284-2-git-send-email-peter@lekensteyn.nl Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2014-08-15dmg: Handle failure for potentially large allocationsKevin Wolf
Some code in the block layer makes potentially huge allocations. Failure is not completely unexpected there, so avoid aborting qemu and handle out-of-memory situations gracefully. This patch addresses the allocations in the dmg block driver. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Benoit Canet <benoit@irqsave.net>
2014-04-30block: Use correct width in format stringsMax Reitz
Instead of blindly relying on a normal integer having a width of 32 bits (which is a pretty good assumption, but we should not rely on it if there is no need), use the correct format string macros. This does not touch DEBUG output. Signed-off-by: Max Reitz <mreitz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2014-04-01dmg: prevent chunk buffer overflow (CVE-2014-0145)Stefan Hajnoczi
Both compressed and uncompressed I/O is buffered. dmg_open() calculates the maximum buffer size needed from the metadata in the image file. There is currently a buffer overflow since ->lengths[] is accounted against the maximum compressed buffer size but actually uses the uncompressed buffer: switch (s->types[chunk]) { case 1: /* copy */ ret = bdrv_pread(bs->file, s->offsets[chunk], s->uncompressed_chunk, s->lengths[chunk]); We must account against the maximum uncompressed buffer size for type=1 chunks. This patch fixes the maximum buffer size calculation to take into account the chunk type. It is critical that we update the correct maximum since there are two buffers ->compressed_chunk and ->uncompressed_chunk. Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2014-04-01dmg: use uint64_t consistently for sectors and lengthsStefan Hajnoczi
The DMG metadata is stored as uint64_t, so use the same type for sector_num. int was a particularly poor choice since it is only 32-bit and would truncate large values. Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2014-04-01dmg: sanitize chunk length and sectorcount (CVE-2014-0145)Stefan Hajnoczi
Chunk length and sectorcount are used for decompression buffers as well as the bdrv_pread() count argument. Ensure that they have reasonable values so neither memory allocation nor conversion from uint64_t to int will cause problems. Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2014-04-01dmg: use appropriate types when reading chunksStefan Hajnoczi
Use the right types instead of signed int: size_t new_size; This is a byte count for g_realloc() that is calculated from uint32_t and size_t values. uint32_t chunk_count; Use the same type as s->n_chunks, which is used together with chunk_count. This patch is a cleanup and does not fix bugs. Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2014-04-01dmg: drop broken bdrv_pread() loopStefan Hajnoczi
It is not necessary to check errno for EINTR and the block layer does not produce short reads. Therefore we can drop the loop that attempts to read a compressed chunk. The loop is buggy because it incorrectly adds the transferred bytes twice: do { ret = bdrv_pread(...); i += ret; } while (ret >= 0 && ret + i < s->lengths[chunk]); Luckily we can drop the loop completely and perform a single bdrv_pread(). Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2014-04-01dmg: prevent out-of-bounds array access on terminatorStefan Hajnoczi
When a terminator is reached the base for offsets and sectors is stored. The following records that are processed will use this base value. If the first record we encounter is a terminator, then calculating the base values would result in out-of-bounds array accesses. Don't do that. Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2014-04-01dmg: coding style and indentation cleanupStefan Hajnoczi
Clean up the mix of tabs and spaces, as well as the coding style violations in block/dmg.c. There are no semantic changes since this patch simply reformats the code. This patch is necessary before we can make meaningful changes to this file, due to the inconsistent formatting and confusing indentation. Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2013-09-12bdrv: Use "Error" for opening imagesMax Reitz
Add an Error ** parameter to BlockDriver.bdrv_open and BlockDriver.bdrv_file_open to allow more specific error messages. Signed-off-by: Max Reitz <mreitz@redhat.com>
2013-03-22block: Make find_image_format safe with NULL filenameKevin Wolf
In order to achieve this, the .bdrv_probe callbacks of all drivers must cope with this. The DMG driver is the only one that bases its decision on the filename and it needs to be changed. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com>
2013-03-15block: Add options QDict to .bdrv_open()Kevin Wolf
Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2013-02-01dmg: Use g_free instead of freeKevin Wolf
The buffers are allocated with g_(re)alloc, so use g_free to free them. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2013-02-01dmg: Fix bdrv_open() error handlingKevin Wolf
Return -errno instead of -1 on errors and add error checks in some places that didn't have one. Passing things by reference requires more correct typing, replaced a few off_ts therefore - with a 32-bit off_t this is even a fix for truncation bugs. While touching the code, fix even some more memory leaks than in the other drivers... Signed-off-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2012-12-19misc: move include files to include/qemu/Paolo Bonzini
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2012-12-19block: move include files to include/block/Paolo Bonzini
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2011-10-21block: take lock around bdrv_read implementationsPaolo Bonzini
This does the first part of the conversion to coroutines, by wrapping bdrv_read implementations to take the mutex. Drivers that implement bdrv_read rather than bdrv_co_readv can then benefit from asynchronous operation (at least if the underlying protocol supports it, which is not the case for raw-win32), even though they still operate with a bounce buffer. raw-win32 does not need the lock, because it cannot yield. nbd also doesn't probably, but better be safe. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-10-21block: add a CoMutex to synchronous read driversPaolo Bonzini
The big conversion of bdrv_read/write to coroutines caused the two homonymous callbacks in BlockDriver to become reentrant. It goes like this: 1) bdrv_read is now called in a coroutine, and calls bdrv_read or bdrv_pread. 2) the nested bdrv_read goes through the fast path in bdrv_rw_co_entry; 3) in the common case when the protocol is file, bdrv_co_do_readv calls bdrv_co_readv_em (and from here goes to bdrv_co_io_em), which yields until the AIO operation is complete; 4) if bdrv_read had been called from a bottom half, the main loop is free to iterate again: a device model or another bottom half can then come and call bdrv_read again. This applies to all four of read/write/flush/discard. It would also apply to is_allocated, but it is not used from within coroutines: besides qemu-img.c and qemu-io.c, which operate synchronously, the only user is the monitor. Copy-on-read will introduce a use in the block layer, and will require converting it. The solution is "simply" to convert all drivers to coroutines! We just need to add a CoMutex that is taken around affected operations. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-08-20Use glib memory allocation and free functionsAnthony Liguori
qemu_malloc/qemu_free no longer exist after this commit. Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2010-05-17dmg: use qemu block APIChristoph Hellwig
Use bdrv_pwrite to access the backing device instead of pread, and convert the driver to implementing the bdrv_open method which gives it an already opened BlockDriverState for the underlying device. Dmg actually does an lseek to a negative offset in the open routine, which we replace with offset arithmetics after doing a bdrv_getlength. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2010-05-17dmg: use preadChristoph Hellwig
Use pread instead of lseek + read in preparation of using the qemu block API. Note that dmg actually uses the implicit file offset a lot in dmg_open, and we had to replace it with an offset variable. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Kevin Wolf <kwolf@redhat.com>