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* fuse: invalidation reverse callsJohn Muir2009-06-304-3/+198
| | | | | | | | | | | | | | | | | | | | | | | | | Add notification messages that allow the filesystem to invalidate VFS caches. Two notifications are added: 1) inode invalidation - invalidate cached attributes - invalidate a range of pages in the page cache (this is optional) 2) dentry invalidation - try to invalidate a subtree in the dentry cache Care must be taken while accessing the 'struct super_block' for the mount, as it can go away while an invalidation is in progress. To prevent this, introduce a rw-semaphore, that is taken for read during the invalidation and taken for write in the ->kill_sb callback. Cc: Csaba Henk <csaba@gluster.com> Cc: Anand Avati <avati@zresearch.com> Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
* fuse: allow umask processing in userspaceMiklos Szeredi2009-06-303-4/+28
| | | | | | | | | | | | | | This patch lets filesystems handle masking the file mode on creation. This is needed if filesystem is using ACLs. - The CREATE, MKDIR and MKNOD requests are extended with a "umask" parameter. - A new FUSE_DONT_MASK flag is added to the INIT request/reply. With this the filesystem may request that the create mode is not masked. CC: Jean-Pierre André <jean-pierre.andre@wanadoo.fr> Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
* fuse: fix bad return value in fuse_file_poll()Miklos Szeredi2009-06-301-1/+1
| | | | | | | | Fix fuse_file_poll() which returned a -errno value instead of a poll mask. Signed-off-by: Miklos Szeredi <mszeredi@suse.cz> CC: stable@kernel.org
* fuse: fix return value of fuse_dev_write()Csaba Henk2009-06-301-1/+1
| | | | | | | | | | | | | On 64 bit systems -- where sizeof(ssize_t) > sizeof(int) -- the following test exposes a bug due to a non-careful return of an int or unsigned value: implement a FUSE filesystem which sends an unsolicited notification to the kernel with invalid opcode. The respective write to /dev/fuse will return (1 << 32) - EINVAL with errno == 0 instead of -1 with errno == EINVAL. Signed-off-by: Miklos Szeredi <mszeredi@suse.cz> CC: stable@kernel.org
* fuse doesn't need BKL in ->umount_begin()Al Viro2009-06-171-3/+0
| | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* Merge branch 'cuse' of ↵Linus Torvalds2009-06-127-231/+939
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse * 'cuse' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse: CUSE: implement CUSE - Character device in Userspace fuse: export symbols to be used by CUSE fuse: update fuse_conn_init() and separate out fuse_conn_kill() fuse: don't use inode in fuse_file_poll fuse: don't use inode in fuse_do_ioctl() helper fuse: don't use inode in fuse_sync_release() fuse: create fuse_do_open() helper for CUSE fuse: clean up args in fuse_finish_open() and fuse_release_fill() fuse: don't use inode in helpers called by fuse_direct_io() fuse: add members to struct fuse_file fuse: prepare fuse_direct_io() for CUSE fuse: clean up fuse_write_fill() fuse: use struct path in release structure fuse: misc cleanups
| * CUSE: implement CUSE - Character device in UserspaceTejun Heo2009-06-092-0/+611
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | CUSE enables implementing character devices in userspace. With recent additions of ioctl and poll support, FUSE already has most of what's necessary to implement character devices. All CUSE has to do is bonding all those components - FUSE, chardev and the driver model - nicely. When client opens /dev/cuse, kernel starts conversation with CUSE_INIT. The client tells CUSE which device it wants to create. As the previous patch made fuse_file usable without associated fuse_inode, CUSE doesn't create super block or inodes. It attaches fuse_file to cdev file->private_data during open and set ff->fi to NULL. The rest of the operation is almost identical to FUSE direct IO case. Each CUSE device has a corresponding directory /sys/class/cuse/DEVNAME (which is symlink to /sys/devices/virtual/class/DEVNAME if SYSFS_DEPRECATED is turned off) which hosts "waiting" and "abort" among other things. Those two files have the same meaning as the FUSE control files. The only notable lacking feature compared to in-kernel implementation is mmap support. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
| * fuse: export symbols to be used by CUSETejun Heo2009-04-284-9/+39
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Export the following symbols for CUSE. fuse_conn_put() fuse_conn_get() fuse_conn_kill() fuse_send_init() fuse_do_open() fuse_sync_release() fuse_direct_io() fuse_do_ioctl() fuse_file_poll() fuse_request_alloc() fuse_get_req() fuse_put_request() fuse_request_send() fuse_abort_conn() fuse_dev_release() fuse_dev_operations Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
| * fuse: update fuse_conn_init() and separate out fuse_conn_kill()Tejun Heo2009-04-283-53/+72
| | | | | | | | | | | | | | | | | | | | | | Update fuse_conn_init() such that it doesn't take @sb and move bdi registration into a separate function. Also separate out fuse_conn_kill() from fuse_put_super(). These will be used to implement cuse. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
| * fuse: don't use inode in fuse_file_pollMiklos Szeredi2009-04-281-3/+2
| | | | | | | | | | | | | | | | | | | | Use ff->fc and ff->nodeid instead of file->f_dentry->d_inode in the fuse_file_poll() implementation. This prepares this function for use by CUSE, where the inode is not owned by a fuse filesystem. Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
| * fuse: don't use inode in fuse_do_ioctl() helperMiklos Szeredi2009-04-281-14/+21
| | | | | | | | | | | | | | | | | | | | Create a helper for sending an IOCTL request that doesn't use a struct inode. This prepares this function for use by CUSE, where the inode is not owned by a fuse filesystem. Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
| * fuse: don't use inode in fuse_sync_release()Miklos Szeredi2009-04-283-39/+36
| | | | | | | | | | | | | | | | | | Make fuse_sync_release() a generic helper function that doesn't need a struct inode pointer. This makes it suitable for use by CUSE. Change return value of fuse_release_common() from int to void. Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
| * fuse: create fuse_do_open() helper for CUSEMiklos Szeredi2009-04-283-27/+42
| | | | | | | | | | | | | | Create a helper for sending an OPEN request that doesn't need a struct inode pointer. Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
| * fuse: clean up args in fuse_finish_open() and fuse_release_fill()Miklos Szeredi2009-04-283-23/+30
| | | | | | | | | | | | | | | | | | | | | | Move setting ff->fh, ff->nodeid and file->private_data outside fuse_finish_open(). Add ->open_flags member to struct fuse_file. This simplifies the argument passing to fuse_finish_open() and fuse_release_fill(), and paves the way for creating an open helper that doesn't need an inode pointer. Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
| * fuse: don't use inode in helpers called by fuse_direct_io()Miklos Szeredi2009-04-283-34/+32
| | | | | | | | | | | | | | | | | | Use ff->fc and ff->nodeid instead of passing down the inode. This prepares this function for use by CUSE, where the inode is not owned by a fuse filesystem. Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
| * fuse: add members to struct fuse_fileMiklos Szeredi2009-04-282-2/+10
| | | | | | | | | | | | | | | | Add new members ->fc and ->nodeid to struct fuse_file. This will aid in converting functions for use by CUSE, where the inode is not owned by a fuse filesystem. Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
| * fuse: prepare fuse_direct_io() for CUSEMiklos Szeredi2009-04-281-10/+23
| | | | | | | | | | | | | | | | | | Move code operating on the inode out from fuse_direct_io(). This prepares this function for use by CUSE, where the inode is not owned by a fuse filesystem. Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
| * fuse: clean up fuse_write_fill()Miklos Szeredi2009-04-281-9/+8
| | | | | | | | | | | | | | | | | | | | Move out code from fuse_write_fill() which is not common to all callers. Remove two function arguments which become unnecessary. Also remove unnecessary memset(), the request is already initialized to zero. Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
| * fuse: use struct path in release structureMiklos Szeredi2009-04-282-7/+5
| | | | | | | | | | | | | | Use struct path instead of separate dentry and vfsmount in req->misc.release. Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
| * fuse: misc cleanupsTejun Heo2009-04-281-37/+44
| | | | | | | | | | | | | | | | | | | | | | | | * fuse_file_alloc() was structured in weird way. The success path was split between else block and code following the block. Restructure the code such that it's easier to read and modify. * Unindent success path of fuse_release_common() to ease future changes. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
* | Merge branch 'for-linus' of ↵Linus Torvalds2009-05-131-0/+1
|\ \ | |/ | | | | | | | | | | 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
| * fuse: destroy bdi on errorMiklos Szeredi2009-04-281-0/+1
| | | | | | | | | | | | | | | | | | | | | | Destroy bdi on error in fuse_fill_super(). This was an omission from commit 26c3679101dbccc054dcf370143941844ba70531 "fuse: destroy bdi on umount", which moved the bdi_destroy() call from fuse_conn_put() to fuse_put_super(). Signed-off-by: Miklos Szeredi <mszeredi@suse.cz> CC: stable@kernel.org
* | vfs: umount_begin BKL pushdownAlessio Igor Bogani2009-05-091-0/+3
|/ | | | | | | Push BKL down into ->umount_begin() Signed-off-by: Alessio Igor Bogani <abogani@texware.it> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* fuse: fix "direct_io" private mmapMiklos Szeredi2009-04-091-0/+2
| | | | | | | | | MAP_PRIVATE mmap could return stale data from the cache for "direct_io" files. Fix this by flushing the cache on mmap. Found with a slightly modified fsx-linux. Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
* fuse: fix argument type in fuse_get_user_pages()Miklos Szeredi2009-04-091-3/+3
| | | | | | | | | | | | Fix the following warning: fs/fuse/file.c: In function 'fuse_direct_io': fs/fuse/file.c:1002: warning: passing argument 3 of 'fuse_get_user_pages' from incompatible pointer type This was introduced by commit f4975c67 "fuse: allow kernel to access "direct_io" files". Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
* fuse: allow private mappings of "direct_io" filesMiklos Szeredi2009-04-021-1/+11
| | | | | | | | | | | | Allow MAP_PRIVATE mmaps of "direct_io" files. This is necessary for execute support. MAP_SHARED mappings require some sort of coherency between the underlying file and the mapping. With "direct_io" it is difficult to provide this, so for the moment just disallow shared (read-write and read-only) mappings altogether. Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
* fuse: allow kernel to access "direct_io" filesMiklos Szeredi2009-04-022-12/+31
| | | | | | | | | | | Allow the kernel read and write on "direct_io" files. This is necessary for nfs export and execute support. The implementation is simple: if an access from the kernel is detected, don't perform get_user_pages(), just use the kernel address provided by the requester to copy from/to the userspace filesystem. Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
* mm: page_mkwrite change prototype to match faultNick Piggin2009-04-011-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | Change the page_mkwrite prototype to take a struct vm_fault, and return VM_FAULT_xxx flags. There should be no functional change. This makes it possible to return much more detailed error information to the VM (and also can provide more information eg. virtual_address to the driver, which might be important in some special cases). This is required for a subsequent fix. And will also make it easier to merge page_mkwrite() with fault() in future. Signed-off-by: Nick Piggin <npiggin@suse.de> Cc: Chris Mason <chris.mason@oracle.com> Cc: Trond Myklebust <trond.myklebust@fys.uio.no> Cc: Miklos Szeredi <miklos@szeredi.hu> Cc: Steven Whitehouse <swhiteho@redhat.com> Cc: Mark Fasheh <mfasheh@suse.com> Cc: Joel Becker <joel.becker@oracle.com> Cc: Artem Bityutskiy <dedekind@infradead.org> Cc: Felix Blyakher <felixb@sgi.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* fuse: fix fuse_file_lseek returning with lock heldDan Carpenter2009-03-301-1/+2
| | | | | | | | | This bug was found with smatch (http://repo.or.cz/w/smatch.git/). If we return directly the inode->i_mutex lock doesn't get released. Signed-off-by: Dan Carpenter <error27@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@suse.cz> CC: stable@kernel.org
* constify dentry_operations: FUSEAl Viro2009-03-272-2/+2
| | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* Merge branch 'Kconfig' of ↵Linus Torvalds2009-01-261-0/+15
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/adobriyan/misc * 'Kconfig' of git://git.kernel.org/pub/scm/linux/kernel/git/adobriyan/misc: (36 commits) fs/Kconfig: move 9p out fs/Kconfig: move afs out fs/Kconfig: move coda out fs/Kconfig: move the rest of ncpfs out fs/Kconfig: move smbfs out fs/Kconfig: move sunrpc out fs/Kconfig: move nfsd out fs/Kconfig: move nfs out fs/Kconfig: move ufs out fs/Kconfig: move sysv out fs/Kconfig: move romfs out fs/Kconfig: move qnx4 out fs/Kconfig: move hpfs out fs/Kconfig: move omfs out fs/Kconfig: move minix out fs/Kconfig: move vxfs out fs/Kconfig: move squashfs out fs/Kconfig: move cramfs out fs/Kconfig: move efs out fs/Kconfig: move bfs out ...
| * fs/Kconfig: move fuse outAlexey Dobriyan2009-01-221-0/+15
| | | | | | | | Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
* | fuse: fix poll notifyMiklos Szeredi2009-01-261-4/+9
| | | | | | | | | | | | | | | | | | Move fuse_copy_finish() to before calling fuse_notify_poll_wakeup(). This is not a big issue because fuse_notify_poll_wakeup() should be atomic, but it's cleaner this way, and later uses of notification will need to be able to finish the copying before performing some actions. Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
* | fuse: destroy bdi on umountMiklos Szeredi2009-01-262-2/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If a fuse filesystem is unmounted but the device file descriptor remains open and a new mount reuses the old device number, then the mount fails with EEXIST and the following warning is printed in the kernel log: WARNING: at fs/sysfs/dir.c:462 sysfs_add_one+0x35/0x3d() sysfs: duplicate filename '0:15' can not be created The cause is that the bdi belonging to the fuse filesystem was destoryed only after the device file was released. Fix this by calling bdi_destroy() from fuse_put_super() instead. Signed-off-by: Miklos Szeredi <mszeredi@suse.cz> CC: stable@kernel.org
* | fuse: fuse_fill_super error handling cleanupMiklos Szeredi2009-01-261-18/+19
| | | | | | | | | | | | Clean up error handling for the whole of fuse_fill_super() function. Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
* | fuse: fix missing fput on errorMiklos Szeredi2009-01-261-2/+7
| | | | | | | | | | | | | | | | Fix the leaking file reference if allocation or initialization of fuse_conn failed. Signed-off-by: Miklos Szeredi <mszeredi@suse.cz> CC: stable@kernel.org
* | fuse: fix NULL deref in fuse_file_alloc()Dan Carpenter2009-01-261-1/+1
|/ | | | | | | | ff is set to NULL and then dereferenced on line 65. Compile tested only. Signed-off-by: Dan Carpenter <error27@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@suse.cz> CC: stable@kernel.org
* Merge branch 'for-linus' of ↵Linus Torvalds2009-01-066-171/+693
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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: clean up annotations of fc->lock fuse: fix sparse warning in ioctl fuse: update interface version fuse: add fuse_conn->release() fuse: separate out fuse_conn_init() from new_conn() fuse: add fuse_ prefix to several functions fuse: implement poll support fuse: implement unsolicited notification fuse: add file kernel handle fuse: implement ioctl support fuse: don't let fuse_req->end() put the base reference fuse: move FUSE_MINOR to miscdevice.h fuse: style fixes
| * fuse: clean up annotations of fc->lockHarvey Harrison2008-12-022-5/+16
| | | | | | | | | | | | | | | | Makes the existing annotations match the more common one per line style and adds a few missing annotations. Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
| * fuse: fix sparse warning in ioctlMiklos Szeredi2008-12-021-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | Fix sparse warning: CHECK fs/fuse/file.c fs/fuse/file.c:1615:17: warning: incorrect type in assignment (different address spaces) fs/fuse/file.c:1615:17: expected void [noderef] <asn:1>*iov_base fs/fuse/file.c:1615:17: got void *<noident> This was introduced by "fuse: implement ioctl support". Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
| * fuse: add fuse_conn->release()Tejun Heo2008-11-262-1/+10
| | | | | | | | | | | | | | | | Add fuse_conn->release() so that fuse_conn can be embedded in other structures. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
| * fuse: separate out fuse_conn_init() from new_conn()Tejun Heo2008-11-262-57/+67
| | | | | | | | | | | | | | | | | | | | Separate out fuse_conn_init() from new_conn() and while at it initialize fuse_conn->entry during conn initialization. This will be used by CUSE. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
| * fuse: add fuse_ prefix to several functionsTejun Heo2008-11-265-52/+54
| | | | | | | | | | | | | | | | | | | | Add fuse_ prefix to request_send*() and get_root_inode() as some of those functions will be exported for CUSE. With or without CUSE export, having the function names scoped is a good idea for debuggability. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
| * fuse: implement poll supportTejun Heo2008-11-264-0/+172
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Implement poll support. Polled files are indexed using kh in a RB tree rooted at fuse_conn->polled_files. Client should send FUSE_NOTIFY_POLL notification once after processing FUSE_POLL which has FUSE_POLL_SCHEDULE_NOTIFY set. Sending notification unconditionally after the latest poll or everytime file content might have changed is inefficient but won't cause malfunction. fuse_file_poll() can sleep and requires patches from the following thread which allows f_op->poll() to sleep. http://thread.gmane.org/gmane.linux.kernel/726176 Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
| * fuse: implement unsolicited notificationTejun Heo2008-11-261-2/+25
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Clients always used to write only in response to read requests. To implement poll efficiently, clients should be able to issue unsolicited notifications. This patch implements basic notification support. Zero fuse_out_header.unique is now accepted and considered unsolicited notification and the error field contains notification code. This patch doesn't implement any actual notification. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
| * fuse: add file kernel handleTejun Heo2008-11-264-4/+15
| | | | | | | | | | | | | | | | | | | | | | | | | | | | The file handle, fuse_file->fh, is opaque value supplied by userland FUSE server and uniqueness is not guaranteed. Add file kernel handle, fuse_file->kh, which is allocated by the kernel on file allocation and guaranteed to be unique. This will be used by poll to match notification to the respective file but can be used for other purposes where unique file handle is necessary. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
| * fuse: implement ioctl supportTejun Heo2008-11-261-0/+280
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Generic ioctl support is tricky to implement because only the ioctl implementation itself knows which memory regions need to be read and/or written. To support this, fuse client can request retry of ioctl specifying memory regions to read and write. Deep copying (nested pointers) can be implemented by retrying multiple times resolving one depth of dereference at a time. For security and cleanliness considerations, ioctl implementation has restricted mode where the kernel determines data transfer directions and sizes using the _IOC_*() macros on the ioctl command. In this mode, retry is not allowed. For all FUSE servers, restricted mode is enforced. Unrestricted ioctl will be used by CUSE. Plese read the comment on top of fs/fuse/file.c::fuse_file_do_ioctl() for more information. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
| * fuse: don't let fuse_req->end() put the base referenceTejun Heo2008-11-263-7/+4
| | | | | | | | | | | | | | | | | | fuse_req->end() was supposed to be put the base reference but there's no reason why it should. It only makes things more complex. Move it out of ->end() and make it the responsibility of request_end(). Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
| * fuse: style fixesMiklos Szeredi2008-11-266-47/+54
| | | | | | | | | | | | | | Fix coding style errors reported by checkpatch and others. Uptdate copyright date to 2008. Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
* | fs: symlink write_begin allocation context fixNick Piggin2009-01-041-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | With the write_begin/write_end aops, page_symlink was broken because it could no longer pass a GFP_NOFS type mask into the point where the allocations happened. They are done in write_begin, which would always assume that the filesystem can be entered from reclaim. This bug could cause filesystem deadlocks. The funny thing with having a gfp_t mask there is that it doesn't really allow the caller to arbitrarily tinker with the context in which it can be called. It couldn't ever be GFP_ATOMIC, for example, because it needs to take the page lock. The only thing any callers care about is __GFP_FS anyway, so turn that into a single flag. Add a new flag for write_begin, AOP_FLAG_NOFS. Filesystems can now act on this flag in their write_begin function. Change __grab_cache_page to accept a nofs argument as well, to honour that flag (while we're there, change the name to grab_cache_page_write_begin which is more instructive and does away with random leading underscores). This is really a more flexible way to go in the end anyway -- if a filesystem happens to want any extra allocations aside from the pagecache ones in ints write_begin function, it may now use GFP_KERNEL (rather than GFP_NOFS) for common case allocations (eg. ocfs2_alloc_write_ctxt, for a random example). [kosaki.motohiro@jp.fujitsu.com: fix ubifs] [kosaki.motohiro@jp.fujitsu.com: fix fuse] Signed-off-by: Nick Piggin <npiggin@suse.de> Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: <stable@kernel.org> [2.6.28.x] Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> [ Cleaned up the calling convention: just pass in the AOP flags untouched to the grab_cache_page_write_begin() function. That just simplifies everybody, and may even allow future expansion of the logic. - Linus ] Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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