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2017-11-17block: Deprecate bdrv_set_read_only() and usersKevin Wolf1-3/+10
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>
2017-04-24block: do not set BDS read_only if copy_on_read enabledJeff Cody1-1/+4
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 Cody1-1/+1
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 Wolf1-0/+1
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 Wolf1-0/+6
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>
2016-07-05block: Convert bdrv_co_preadv/pwritev to BdrvChildKevin Wolf1-1/+1
This is the final patch for converting the common I/O path to take a BdrvChild parameter instead of BlockDriverState. The completion of this conversion means that all users that perform I/O on an image need to actually hold a reference (in the form of BdrvChild, possible as part of a BlockBackend) to that image. This also protects against inconsistent use of BlockBackend vs. BlockDriverState functions because direct use of a BlockDriverState isn't possible any more and blk->root is private for block-backends.c. In addition, we can now distinguish different users in the I/O path, and the future op blockers work is going to add assertions based on permissions stored in BdrvChild. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
2016-07-05block: Convert bdrv_pread(v) to BdrvChildKevin Wolf1-3/+3
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 Blake1-1/+1
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 Blake1-1/+1
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 Blake1-1/+6
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>
2016-05-19qemu-common: stop including qemu/bswap.h from qemu-common.hPaolo Bonzini1-0/+1
Move it to the actual users. There are still a few includes of qemu/bswap.h in headers; removing them is left for future work. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-05-12bochs: Implement .bdrv_co_preadv() interfaceKevin Wolf1-18/+33
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 Armbruster1-0/+1
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 Maydell1-0/+1
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 Wolf1-4/+4
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>
2014-08-20block: Use g_new() & friends to avoid multiplying sizesMarkus Armbruster1-1/+1
g_new(T, n) is safer than g_malloc(sizeof(*v) * n) for two reasons. One, it catches multiplication overflowing size_t. Two, it returns T * rather than void *, which lets the compiler catch more type errors. Perhaps a conversion to g_malloc_n() would be neater in places, but that's merely four years old, and we can't use such newfangled stuff. This commit only touches allocations with size arguments of the form sizeof(T), plus two that use 4 instead of sizeof(uint32_t). We can make the others safe by converting to g_malloc_n() when it becomes available to us in a couple of years. Signed-off-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Jeff Cody <jcody@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2014-08-15bochs: Handle failure for potentially large allocationsKevin Wolf1-1/+5
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 bochs 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/bochs: Fix error handling for seek_to_sector()Max Reitz1-9/+14
Currently, seek_to_sector() returns -1 both for errors and unallocated sectors, resulting in silent errors. As 0 is an invalid offset of data clusters (bitmap_offset is greater than 0 because s->data_offset is greater than 0), just return 0 for unallocated sectors and -errno in case of error. This should then be propagated by bochs_read(), the sole user of seek_to_sector(). That function also has a case of "return -1 in case of error", which is fixed by this patch as well. bochs_read() is called by bochs_co_read() which passes the return value through, therefore it is indeed correct for bochs_read() to return -errno. Signed-off-by: Max Reitz <mreitz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2014-04-11bochs: Fix catalog size checkKevin Wolf1-3/+11
The old check was off by a factor of 512 and didn't consider cases where we don't get an exact division. This could lead to an out-of-bounds array access in seek_to_sector(). Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Laszlo Ersek <lersek@redhat.com>
2014-04-11bochs: Fix memory leak in bochs_open() error pathKevin Wolf1-2/+4
Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Laszlo Ersek <lersek@redhat.com>
2014-04-01bochs: Fix bitmap offset calculationKevin Wolf1-2/+3
32 bit truncation could let us access the wrong offset in the image. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2014-04-01bochs: Check extent_size header field (CVE-2014-0142)Kevin Wolf1-0/+8
This fixes two possible division by zero crashes: In bochs_open() and in seek_to_sector(). Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2014-04-01bochs: Check catalog_size header field (CVE-2014-0143)Kevin Wolf1-0/+13
It should neither become negative nor allow unbounded memory allocations. This fixes aborts in g_malloc() and an s->catalog_bitmap buffer overflow on big endian hosts. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2014-04-01bochs: Use unsigned variables for offsets and sizes (CVE-2014-0147)Kevin Wolf1-8/+8
Gets us rid of integer overflows resulting in negative sizes which aren't correctly checked. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2014-04-01bochs: Unify header structs and make them QEMU_PACKEDKevin Wolf1-42/+25
This is an on-disk structure, so offsets must be accurate. Before this patch, sizeof(bochs) != sizeof(header_v1), which makes the memcpy() between both invalid. We're lucky enough that the destination buffer happened to be the larger one, and the memcpy size to be taken from the smaller one, so we didn't get a buffer overflow in practice. This patch unifies the both structures, eliminating the need to do a memcpy in the first place. The common fields are extracted to the top level of the struct and the actually differing part gets a union of the two versions. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2014-02-21block: do not abuse EMEDIUMTYPEPaolo Bonzini1-1/+2
Returning "Wrong medium type" for an image that does not have a valid header is a bit weird. Improve the error by mentioning what format was trying to open it. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Fam Zheng <famz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2013-09-12bdrv: Use "Error" for opening imagesMax Reitz1-1/+2
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>
2013-03-15block: Add options QDict to .bdrv_open()Kevin Wolf1-1/+1
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>
2013-02-01bochs: Fix bdrv_open() error handlingKevin Wolf1-7/+15
Return -errno instead of -1 on errors. While touching the code, fix a memory leak. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2013-01-25block: Use error code EMEDIUMTYPE for wrong format in some block driversStefan Weil1-1/+1
This improves error reports for bochs, cow, qcow, qcow2, qed and vmdk when a file with the wrong format is selected. Signed-off-by: Stefan Weil <sw@weilnetz.de> Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-12-19misc: move include files to include/qemu/Paolo Bonzini1-1/+1
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2012-12-19block: move include files to include/block/Paolo Bonzini1-1/+1
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2011-10-21block: take lock around bdrv_read implementationsPaolo Bonzini1-1/+12
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 Bonzini1-0/+2
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 Liguori1-2/+2
qemu_malloc/qemu_free no longer exist after this commit. Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2010-05-17bochs: use qemu block APIChristoph Hellwig1-21/+9
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. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2010-05-17bochs: use preadChristoph Hellwig1-43/+20
Use pread instead of lseek + read in preparation of using the qemu block API. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2010-05-03block: Open the underlying image file in generic codeKevin Wolf1-1/+1
Format drivers shouldn't need to bother with things like file names, but rather just get an open BlockDriverState for the underlying protocol. This patch introduces this behaviour for bdrv_open implementation. For protocols which need to access the filename to open their file/device/connection/... a new callback bdrv_file_open is introduced which doesn't get an underlying file opened. For now, also some of the more obscure formats use bdrv_file_open because they open() the file themselves instead of using the block.c functions. They need to be fixed in later patches. Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2010-01-26Read-only device changed to opens it's file for read-only.Naphtali Sprei1-4/+2
Signed-off-by: Naphtali Sprei <nsprei@redhat.com> Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2009-12-25block/bochs: improve format checkingBlue Swirl1-3/+10
Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
2009-12-25block/bochs.c: fix warning with _FORTIFY_SOURCEKirill A. Shutemov1-1/+2
CC block/bochs.o cc1: warnings being treated as errors block/bochs.c: In function 'seek_to_sector': block/bochs.c:202: error: ignoring return value of 'read', declared with attribute warn_unused_result make: *** [block/bochs.o] Error 1 Signed-off-by: Kirill A. Shutemov <kirill@shutemov.name> Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
2009-05-14Move block drivers into their own directoryAnthony Liguori1-0/+259
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>