aboutsummaryrefslogtreecommitdiff
path: root/fs
AgeCommit message (Collapse)Author
2009-05-22block: Export I/O topology for block devices and partitionsMartin K. Petersen
To support devices with physical block sizes bigger than 512 bytes we need to ensure proper alignment. This patch adds support for exposing I/O topology characteristics as devices are stacked. logical_block_size is the smallest unit the device can address. physical_block_size indicates the smallest I/O the device can write without incurring a read-modify-write penalty. The io_min parameter is the smallest preferred I/O size reported by the device. In many cases this is the same as the physical block size. However, the io_min parameter can be scaled up when stacking (RAID5 chunk size > physical block size). The io_opt characteristic indicates the optimal I/O size reported by the device. This is usually the stripe width for arrays. The alignment_offset parameter indicates the number of bytes the start of the device/partition is offset from the device's natural alignment. Partition tools and MD/DM utilities can use this to pad their offsets so filesystems start on proper boundaries. Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-05-22block: Use accessor functions for queue limitsMartin K. Petersen
Convert all external users of queue limits to using wrapper functions instead of poking the request queue variables directly. Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-05-22block: Do away with the notion of hardsect_sizeMartin K. Petersen
Until now we have had a 1:1 mapping between storage device physical block size and the logical block sized used when addressing the device. With SATA 4KB drives coming out that will no longer be the case. The sector size will be 4KB but the logical block size will remain 512-bytes. Hence we need to distinguish between the physical block size and the logical ditto. This patch renames hardsect_size to logical_block_size. Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-05-22Merge branch 'master' into for-2.6.31Jens Axboe
Conflicts: drivers/ide/ide-io.c Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-05-22Merge branch 'master' into for-2.6.31Jens Axboe
Conflicts: drivers/block/hd.c drivers/block/mg_disk.c Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-05-22Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/ryusuke/nilfs2 * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ryusuke/nilfs2: nilfs2: fix memory leak in nilfs_ioctl_clean_segments
2009-05-22nilfs2: fix memory leak in nilfs_ioctl_clean_segmentsRyusuke Konishi
This fixes a new memory leak problem in garbage collection. The problem was brought by the bugfix patch ("nilfs2: fix lock order reversal in nilfs_clean_segments ioctl"). Thanks to Kentaro Suzuki for finding this problem. Reported-by: Kentaro Suzuki <k_suzuki@ms.sylc.co.jp> Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
2009-05-21[CIFS] fix posix open regressionSteve French
Posix open code was not properly adding the file to the list of open files. Fix allocating cifsFileInfo more than once, and adding twice to flist and tlist. Also fix mode setting to be done in one place in these paths. Signed-off-by: Steve French <sfrench@us.ibm.com> Reviewed-by: Shirish Pargaonkar <shirishp@us.ibm.com> Tested-by: Jeff Layton <jlayton@redhat.com> Tested-by: Luca Tettamanti <kronos.it@gmail.com>
2009-05-20Merge git://git.kernel.org/pub/scm/linux/kernel/git/sfrench/cifs-2.6Linus Torvalds
* git://git.kernel.org/pub/scm/linux/kernel/git/sfrench/cifs-2.6: cifs: fix pointer initialization and checks in cifs_follow_symlink (try #4)
2009-05-19cifs: fix pointer initialization and checks in cifs_follow_symlink (try #4)Jeff Layton
This is the third respin of the patch posted yesterday to fix the error handling in cifs_follow_symlink. It also includes a fix for a bogus NULL pointer check in CIFSSMBQueryUnixSymLink that Jeff Moyer spotted. It's possible for CIFSSMBQueryUnixSymLink to return without setting target_path to a valid pointer. If that happens then the current value to which we're initializing this pointer could cause an oops when it's kfree'd. This patch is a little more comprehensive than the last patches. It reorganizes cifs_follow_link a bit for (hopefully) better readability. It should also eliminate the uneeded allocation of full_path on servers without unix extensions (assuming they can get to this point anyway, of which I'm not convinced). On a side note, I'm not sure I agree with the logic of enabling this query even when unix extensions are disabled on the client. It seems like that should disable this as well. But, changing that is outside the scope of this fix, so I've left it alone for now. Reported-by: Jeff Moyer <jmoyer@redhat.com> Signed-off-by: Jeff Layton <jlayton@redhat.com> Reviewed-by: Jeff Moyer <jmoyer@redhat.com> Reviewed-by: Christoph Hellwig <hch@inraded.com> Signed-off-by: Steve French <sfrench@us.ibm.com>
2009-05-19splice: fix kmaps in default_file_splice_write()Miklos Szeredi
Unfortunately multiple kmap() within a single thread are deadlockable, so writing out multiple buffers with writev() isn't possible. Change the implementation so that it does a separate write() for each buffer. This actually simplifies the code a lot since the splice_from_pipe() helper can be used. This limitation is caused by HIGHMEM pages, and so only affects a subset of architectures and configurations. In the future it may be worth to implement default_file_splice_write() in a more efficient way on configs that allow it. Signed-off-by: Miklos Szeredi <mszeredi@suse.cz> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-05-19bio: always copy back data for copied kernel requestsTejun Heo
When a read bio_copy_kern() request fails, the content of the bounce buffer is not copied back. However, as request failure doesn't necessarily mean complete failure, the buffer state can be useful. This behavior is also inconsistent with the user map counterpart and causes the subtle difference between bounced and unbounced IO causes confusion. This patch makes bio_copy_kern_endio() ignore @err and always copy back data on request completion. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Boaz Harrosh <bharrosh@panasas.com> Cc: James Bottomley <James.Bottomley@HansenPartnership.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-05-18nfs: Fix NFS v4 client handling of MAY_EXEC in nfs_permission.Frank Filz
The problem is that permission checking is skipped if atomic open is possible, but when exec opens a file, it just opens it O_READONLY which means EXEC permission will not be checked at that time. This problem is observed by the following sequence (executed as root): mount -t nfs4 server:/ /mnt4 echo "ls" >/mnt4/foo chmod 744 /mnt4/foo su guest -c "mnt4/foo" Signed-off-by: Frank Filz <ffilzlnx@us.ibm.com> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com> Cc: stable@kernel.org Tested-by: Eugene Teo <eugeneteo@kernel.sg> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-05-17reiserfs: fixup perms when xattrs are disabledJeff Mahoney
This adds CONFIG_REISERFS_FS_XATTR protection from reiserfs_permission. This is needed to avoid warnings during file deletions and chowns with xattrs disabled. Signed-off-by: Jeff Mahoney <jeffm@suse.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-05-17reiserfs: deal with NULL xattr root w/ xattrs disabledJeff Mahoney
This avoids an Oops in open_xa_root that can occur when deleting a file with xattrs disabled. It assumes that the xattr root will be there, and that is not guaranteed. Signed-off-by: Jeff Mahoney <jeffm@suse.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-05-17reiserfs: clean up ifdefsJeff Mahoney
With xattr cleanup even with xattrs disabled, much of the initial setup is still performed. Some #ifdefs are just not needed since the options they protect wouldn't be available anyway. This cleans those up. Signed-off-by: Jeff Mahoney <jeffm@suse.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-05-15Merge branch 'for_linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4 * 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4: ext4: Fix race in ext4_inode_info.i_cached_extent ext4: Clear the unwritten buffer_head flag after the extent is initialized ext4: Use a fake block number for delayed new buffer_head ext4: Fix sub-block zeroing for writes into preallocated extents
2009-05-15devpts: correctly set default optionsSukadev Bhattiprolu
devpts_get_sb() calls memset(0) to clear mount options and calls parse_mount_options() if user specified any mount options. The memset(0) is bogus since the 'mode' and 'ptmxmode' options are non-zero by default. parse_mount_options() restores options to default anyway and can properly deal with NULL mount options. So in devpts_get_sb() remove memset(0) and call parse_mount_options() even for NULL mount options. Bug reported by Eric Paris: http://lkml.org/lkml/2009/5/7/448. Signed-off-by: Sukadev Bhattiprolu <sukadev@us.ibm.com> Tested-by: Marc Dionne <marc.c.dionne@gmail.com> Reported-by: Eric Paris <eparis@redhat.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Acked-by: Serge Hallyn <serue@us.ibm.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: "Rafael J. Wysocki" <rjw@sisk.pl> Reviewed-by: "H. Peter Anvin" <hpa@zytor.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-05-15ext4: Fix race in ext4_inode_info.i_cached_extentTheodore Ts'o
If two CPU's simultaneously call ext4_ext_get_blocks() at the same time, there is nothing protecting the i_cached_extent structure from being used and updated at the same time. This could potentially cause the wrong location on disk to be read or written to, including potentially causing the corruption of the block group descriptors and/or inode table. This bug has been in the ext4 code since almost the very beginning of ext4's development. Fortunately once the data is stored in the page cache cache, ext4_get_blocks() doesn't need to be called, so trying to replicate this problem to the point where we could identify its root cause was *extremely* difficult. Many thanks to Kevin Shanahan for working over several months to be able to reproduce this easily so we could finally nail down the cause of the corruption. Signed-off-by: "Theodore Ts'o" <tytso@mit.edu> Reviewed-by: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
2009-05-14Merge git://git.kernel.org/pub/scm/linux/kernel/git/sfrench/cifs-2.6Linus Torvalds
* git://git.kernel.org/pub/scm/linux/kernel/git/sfrench/cifs-2.6: cifs: fix error handling in parse_DFS_referrals
2009-05-14Merge git://git.kernel.org/pub/scm/linux/kernel/git/mason/btrfs-unstableLinus Torvalds
* git://git.kernel.org/pub/scm/linux/kernel/git/mason/btrfs-unstable: Btrfs: Spelling fix in btrfs_lookup_first_block_group comments Btrfs: make show_options result match actual option names Btrfs: remove outdated comment in btrfs_ioctl_resize() Btrfs: remove some WARN_ONs in the IO failure path Btrfs: Don't loop forever on metadata IO failures Btrfs: init inode ordered_data_close flag properly
2009-05-14ext4: Clear the unwritten buffer_head flag after the extent is initializedAneesh Kumar K.V
The BH_Unwritten flag indicates that the buffer is allocated on disk but has not been written; that is, the disk was part of a persistent preallocation area. That flag should only be set when a get_blocks() function is looking up a inode's logical to physical block mapping. When ext4_get_blocks_wrap() is called with create=1, the uninitialized extent is converted into an initialized one, so the BH_Unwritten flag is no longer appropriate. Hence, we need to make sure the BH_Unwritten is not left set, since the combination of BH_Mapped and BH_Unwritten is not allowed; among other things, it will result ext4's get_block() to be called over and over again during the write_begin phase of write(2). Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2009-05-14Btrfs: Spelling fix in btrfs_lookup_first_block_group commentsSankar P
Signed-off-by: Sankar P <sankar.curiosity@gmail.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-05-14Btrfs: make show_options result match actual option namesSage Weil
The notreelog and flushoncommit mount options were being printed slightly differently. Signed-off-by: Sage Weil <sage@newdream.net> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-05-14Btrfs: remove outdated comment in btrfs_ioctl_resize()Li Hong
In Li Zefan's commit dae7b665cf6d6e6e733f1c9c16cf55547dd37e33, a combination call of kmalloc() and copy_from_user() is replaced by memdup_user(). So btrfs_ioctl_resize() doesn't use GFP_NOFS any more. Signed-off-by: Li Hong <lihong.hi@gmail.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-05-14Btrfs: remove some WARN_ONs in the IO failure pathChris Mason
These debugging WARN_ONs make too much console noise during regular IO failures. An IO failure will still generate a number of messages as we verify checksums etc, but these two are not needed. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-05-14Btrfs: Don't loop forever on metadata IO failuresChris Mason
When a btrfs metadata read fails, the first thing we try to do is find a good copy on another mirror of the block. If this fails, read_tree_block() ends up returning a buffer that isn't up to date. The btrfs btree reading code was reworked to drop locks and repeat the search when IO was done, but the changes didn't add a check for failed reads. The end result was looping forever on buffers that were never going to become up to date. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-05-14Btrfs: init inode ordered_data_close flag properlyChris Mason
This flag is used to decide when we need to send a given file through the ordered code to make sure it is fully written before a transaction commits. It was not being properly set to zero when the inode was being setup. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-05-14cifs: fix error handling in parse_DFS_referralsJeff Layton
cifs_strndup_from_ucs returns NULL on error, not an ERR_PTR Signed-off-by: Jeff Layton <jlayton@redhat.com> Signed-off-by: Steve French <sfrench@us.ibm.com>
2009-05-14splice: fix error return codeAndrew Morton
fs/splice.c: In function 'default_file_splice_read': fs/splice.c:566: warning: 'error' may be used uninitialized in this function which is sort-of true. The code will in fact return -ENOMEM instead of the kernel_readv() return value. Cc: Miklos Szeredi <miklos@szeredi.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-05-13Merge git://git.kernel.org/pub/scm/linux/kernel/git/pkl/squashfs-linusLinus Torvalds
* git://git.kernel.org/pub/scm/linux/kernel/git/pkl/squashfs-linus: Squashfs: cody tidying, remove commented out line in Makefile Squashfs: check page size is not larger than the filesystem block size Squashfs: fix breakage when page size > metadata block size
2009-05-13Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse: fuse: destroy bdi on error
2009-05-13Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/ryusuke/nilfs2 * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ryusuke/nilfs2: nilfs2: check size of array structured data exchanged via ioctls nilfs2: fix lock order reversal in nilfs_clean_segments ioctl nilfs2: fix possible circular locking for get information ioctls nilfs2: ensure to clear dirty state when deleting metadata file block nilfs2: fix circular locking dependency of writer mutex nilfs2: fix possible recovery failure due to block creation without writer
2009-05-13Remove implementation of readpage from the hugetlbfs_aopsMel Gorman
The core VM assumes the page size used by the address_space in inode->i_mapping is PAGE_SIZE but hugetlbfs breaks this assumption by inserting pages into the page cache at offsets the core VM considers unexpected. This would not be a problem except that hugetlbfs also provide a ->readpage implementation. As it exists, the core VM can assume the base page size is being used, allocate pages on behalf of the filesystem, insert them into the page cache and call ->readpage to populate them. These pages are the wrong size and at the wrong offset for hugetlbfs causing confusion. This patch deletes the ->readpage implementation for hugetlbfs on the grounds the core VM should not be allocating and populating pages on behalf of hugetlbfs. There should be no existing users of the ->readpage implementation so it should not cause a regression. Signed-off-by: Mel Gorman <mel@csn.ul.ie> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-05-13splice: fix repeated kmap()'s in default_file_splice_read()Jens Axboe
We cannot reliably map more than one page at the time, or we risk deadlocking. Just allocate the pages from low mem instead. Reported-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-05-13Squashfs: cody tidying, remove commented out line in MakefilePhillip Lougher
Signed-off-by: Phillip Lougher <phillip@lougher.demon.co.uk>
2009-05-13Squashfs: check page size is not larger than the filesystem block sizePhillip Lougher
Normally the block size (by default 128K) will be larger than the page size, unless a non-standard block size has been specified in Mksquashfs, and the page size is larger than 4K. Signed-off-by: Phillip Lougher <phillip@lougher.demon.co.uk>
2009-05-13Squashfs: fix breakage when page size > metadata block sizeDoug Chapman
Squashfs is broken on any system where the page size is larger than the metadata size (8192). This is easily fixed by ensuring cache->pages is always > 0. [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: Doug Chapman <doug.chapman@hp.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Phillip Lougher <phillip@lougher.demon.co.uk>
2009-05-12Merge branch 'for-2.6.30' of git://linux-nfs.org/~bfields/linuxLinus Torvalds
* 'for-2.6.30' of git://linux-nfs.org/~bfields/linux: nfsd: silence lockdep warning lockd: fix list corruption on lockd restart nfsd4: check for negative dentry before use in nfsv4 readdir nfsd41: slots are freed with session svcrdma: clean up error paths. svcrdma: Fix dma map direction for rdma read targets
2009-05-12epoll: fix size check in epoll_create()Davide Libenzi
Fix a size check WRT the manual pages. This was inadvertently broken by commit 9fe5ad9c8cef9ad5873d8ee55d1cf00d9b607df0 ("flag parameters add-on: remove epoll_create size param"). Signed-off-by: Davide Libenzi <davidel@xmailserver.org> Cc: <Hiroyuki.Mach@gmail.com> Cc: rohit verma <rohit.170309@gmail.com> Cc: Ulrich Drepper <drepper@redhat.com> Cc: <stable@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-05-12ext4: Use a fake block number for delayed new buffer_headAneesh Kumar K.V
Use a very large unsigned number (~0xffff) as as the fake block number for the delayed new buffer. The VFS should never try to write out this number, but if it does, this will make it obvious. Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2009-05-13ext4: Fix sub-block zeroing for writes into preallocated extentsAneesh Kumar K.V
We need to mark the buffer_head mapping preallocated space as new during write_begin. Otherwise we don't zero out the page cache content properly for a partial write. This will cause file corruption with preallocation. Now that we mark the buffer_head new we also need to have a valid buffer_head blocknr so that unmap_underlying_metadata() unmaps the correct block. Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2009-05-11nfsd: silence lockdep warningJ. Bruce Fields
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
2009-05-11dup2: Fix return value with oldfd == newfd and invalid fdJeff Mahoney
The return value of dup2 when oldfd == newfd and the fd isn't valid is not getting properly sign extended. We end up with 4294967287 instead of -EBADF. I've reproduced this on SLE11 (2.6.27.21), openSUSE Factory (2.6.29-rc5), and Ubuntu 9.04 (2.6.28). This patch uses a signed int for the error value so it is properly extended. Commit 6c5d0512a091480c9f981162227fdb1c9d70e555 introduced this regression. Reported-by: Jiri Dluhos <jdluhos@novell.com> Signed-off-by: Jeff Mahoney <jeffm@suse.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-05-12nilfs2: check size of array structured data exchanged via ioctlsRyusuke Konishi
Although some ioctls of nilfs2 exchange data in the form of indirectly referenced array, some of them lack size check on the array elements. This inserts the missing checks and rejects requests if data of ioctl does not have a valid format. We usually don't have to check size of structures that we associated with ioctl commands because the size is tested implicitly for identifying ioctl command; the checks this patch adds are for the cases where the implicit check is not applied. Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
2009-05-11splice: implement default splice_write methodMiklos Szeredi
If f_op->splice_write() is not implemented, fall back to a plain write. Use vfs_writev() to write from the pipe buffers. This will allow splice on all filesystems and file types. This includes "direct_io" files in fuse which bypass the page cache. Signed-off-by: Miklos Szeredi <mszeredi@suse.cz> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-05-11splice: implement default splice_read methodMiklos Szeredi
If f_op->splice_read() is not implemented, fall back to a plain read. Use vfs_readv() to read into previously allocated pages. This will allow splice and functions using splice, such as the loop device, to work on all filesystems. This includes "direct_io" files in fuse which bypass the page cache. Signed-off-by: Miklos Szeredi <mszeredi@suse.cz> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-05-11splice: implement pipe to pipe splicingMiklos Szeredi
Allow splice(2) to work when both the input and the output is a pipe. Based on the impementation of the tee(2) syscall, but instead of duplicating the buffer references move the buffers from the input pipe to the output pipe. Moving the whole buffer only succeeds if the full length of the buffer is spliced. Otherwise duplicate the buffer, just like tee(2), set the length of the output buffer and advance the offset on the input buffer. Since splice is operating on two pipes, special care needs to be taken with locking to prevent AN ABBA deadlock. Again this is done similarly to the tee(2) syscall, first preparing the input and output pipes so there's data to consume and space for that data, and then doing the move operation while holding both locks. If other processes are doing I/O on the same pipes parallel to the splice, then by the time both inodes are locked there might be no buffers left to move, or no space to move them to. In this case retry the whole operation, including the preparation phase. This could lead to starvation, but I'm not sure if that's serious enough to worry about. Signed-off-by: Miklos Szeredi <mszeredi@suse.cz> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-05-11block: add rq->resid_lenTejun Heo
rq->data_len served two purposes - the length of data buffer on issue and the residual count on completion. This duality creates some headaches. First of all, block layer and low level drivers can't really determine what rq->data_len contains while a request is executing. It could be the total request length or it coulde be anything else one of the lower layers is using to keep track of residual count. This complicates things because blk_rq_bytes() and thus [__]blk_end_request_all() relies on rq->data_len for PC commands. Drivers which want to report residual count should first cache the total request length, update rq->data_len and then complete the request with the cached data length. Secondly, it makes requests default to reporting full residual count, ie. reporting that no data transfer occurred. The residual count is an exception not the norm; however, the driver should clear rq->data_len to zero to signify the normal cases while leaving it alone means no data transfer occurred at all. This reverse default behavior complicates code unnecessarily and renders block PC on some drivers (ide-tape/floppy) unuseable. This patch adds rq->resid_len which is used only for residual count. While at it, remove now unnecessasry blk_rq_bytes() caching in ide_pc_intr() as rq->data_len is not changed anymore. Boaz : spotted missing conversion in osd Sergei : spotted too early conversion to blk_rq_bytes() in ide-tape [ Impact: cleanup residual count handling, report 0 resid by default ] Signed-off-by: Tejun Heo <tj@kernel.org> Cc: James Bottomley <James.Bottomley@HansenPartnership.com> Cc: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com> Cc: Borislav Petkov <petkovbb@googlemail.com> Cc: Sergei Shtylyov <sshtylyov@ru.mvista.com> Cc: Mike Miller <mike.miller@hp.com> Cc: Eric Moore <Eric.Moore@lsi.com> Cc: Alan Stern <stern@rowland.harvard.edu> Cc: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp> Cc: Doug Gilbert <dgilbert@interlog.com> Cc: Mike Miller <mike.miller@hp.com> Cc: Eric Moore <Eric.Moore@lsi.com> Cc: Darrick J. Wong <djwong@us.ibm.com> Cc: Pete Zaitcev <zaitcev@redhat.com> Cc: Boaz Harrosh <bharrosh@panasas.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-05-11nilfs2: fix lock order reversal in nilfs_clean_segments ioctlRyusuke Konishi
This is a companion patch to ("nilfs2: fix possible circular locking for get information ioctls"). This corrects lock order reversal between mm->mmap_sem and nilfs->ns_segctor_sem in nilfs_clean_segments() which was detected by lockdep check: ======================================================= [ INFO: possible circular locking dependency detected ] 2.6.30-rc3-nilfs-00003-g360bdc1 #7 ------------------------------------------------------- mmap/5294 is trying to acquire lock: (&nilfs->ns_segctor_sem){++++.+}, at: [<d0d0e846>] nilfs_transaction_begin+0xb6/0x10c [nilfs2] but task is already holding lock: (&mm->mmap_sem){++++++}, at: [<c043700a>] do_page_fault+0x1d8/0x30a which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (&mm->mmap_sem){++++++}: [<c01470a5>] __lock_acquire+0x1066/0x13b0 [<c01474a9>] lock_acquire+0xba/0xdd [<c01836bc>] might_fault+0x68/0x88 [<c023c61d>] copy_from_user+0x2a/0x111 [<d0d120d0>] nilfs_ioctl_prepare_clean_segments+0x1d/0xf1 [nilfs2] [<d0d0e2aa>] nilfs_clean_segments+0x6d/0x1b9 [nilfs2] [<d0d11f68>] nilfs_ioctl+0x2ad/0x318 [nilfs2] [<c01a3be7>] vfs_ioctl+0x22/0x69 [<c01a408e>] do_vfs_ioctl+0x460/0x499 [<c01a4107>] sys_ioctl+0x40/0x5a [<c01031a4>] sysenter_do_call+0x12/0x38 [<ffffffff>] 0xffffffff -> #0 (&nilfs->ns_segctor_sem){++++.+}: [<c0146e0b>] __lock_acquire+0xdcc/0x13b0 [<c01474a9>] lock_acquire+0xba/0xdd [<c0433f1d>] down_read+0x2a/0x3e [<d0d0e846>] nilfs_transaction_begin+0xb6/0x10c [nilfs2] [<d0cfe0e5>] nilfs_page_mkwrite+0xe7/0x154 [nilfs2] [<c0183b0b>] __do_fault+0x165/0x376 [<c01855cd>] handle_mm_fault+0x287/0x5d1 [<c043712d>] do_page_fault+0x2fb/0x30a [<c0435462>] error_code+0x72/0x78 [<ffffffff>] 0xffffffff where nilfs_clean_segments() holds: nilfs->ns_segctor_sem -> copy_from_user() --> page fault -> mm->mmap_sem And, page fault path may hold: page fault -> mm->mmap_sem --> nilfs_page_mkwrite() -> nilfs->ns_segctor_sem Even though nilfs_clean_segments() does not perform write access on given user pages, it may cause deadlock because nilfs->ns_segctor_sem is shared per device and mm->mmap_sem can be shared with other tasks. To avoid this problem, this patch moves all calls of copy_from_user() outside the nilfs->ns_segctor_sem lock in the ioctl. Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>