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2012-03-06CIFS: Do not kmalloc under the flocks spinlockPavel Shilovsky
Reorganize the code to make the memory already allocated before spinlock'ed loop. Cc: stable@vger.kernel.org Reviewed-by: Jeff Layton <jlayton@redhat.com> Signed-off-by: Pavel Shilovsky <piastry@etersoft.ru> Signed-off-by: Steve French <sfrench@us.ibm.com>
2012-03-06cifs: possible memory leak in xattr.Santosh Nayak
Memory is allocated irrespective of whether CIFS_ACL is configured or not. But free is happenning only if CIFS_ACL is set. This is a possible memory leak scenario. Fix is: Allocate and free memory only if CIFS_ACL is configured. Signed-off-by: Santosh Nayak <santoshprasadnayak@gmail.com> Reviewed-by: Shirish Pargaonkar <shirishpargaonkar@gmail.com> Signed-off-by: Steve French <sfrench@us.ibm.com>
2012-02-26cifs: fix dentry refcount leak when opening a FIFO on lookupJeff Layton
The cifs code will attempt to open files on lookup under certain circumstances. What happens though if we find that the file we opened was actually a FIFO or other special file? Currently, the open filehandle just ends up being leaked leading to a dentry refcount mismatch and oops on umount. Fix this by having the code close the filehandle on the server if it turns out not to be a regular file. While we're at it, change this spaghetti if statement into a switch too. Cc: stable@vger.kernel.org Reported-by: CAI Qian <caiqian@redhat.com> Tested-by: CAI Qian <caiqian@redhat.com> Reviewed-by: Shirish Pargaonkar <shirishpargaonkar@gmail.com> Signed-off-by: Jeff Layton <jlayton@redhat.com> Signed-off-by: Steve French <smfrench@gmail.com>
2012-02-26CIFS: Fix mkdir/rmdir bug for the non-POSIX casePavel Shilovsky
Currently we do inc/drop_nlink for a parent directory for every mkdir/rmdir calls. That's wrong when Unix extensions are disabled because in this case a server doesn't follow the same semantic and returns the old value on the next QueryInfo request. As the result, we update our value with the server one and then decrement it on every rmdir call - go to negative nlink values. Fix this by removing inc/drop_nlink for the parent directory from mkdir/rmdir, setting it for a revalidation and ignoring NumberOfLinks for directories when Unix extensions are disabled. Signed-off-by: Pavel Shilovsky <piastry@etersoft.ru> Reviewed-by: Jeff Layton <jlayton@samba.org> Signed-off-by: Steve French <smfrench@gmail.com>
2012-02-07cifs: don't return error from standard_receive3 after marking response malformedJeff Layton
standard_receive3 will check the validity of the response from the server (via checkSMB). It'll pass the result of that check to handle_mid which will dequeue it and mark it with a status of MID_RESPONSE_MALFORMED if checkSMB returned an error. At that point, standard_receive3 will also return an error, which will make the demultiplex thread skip doing the callback for the mid. This is wrong -- if we were able to identify the request and the response is marked malformed, then we want the demultiplex thread to do the callback. Fix this by making standard_receive3 return 0 in this situation. Cc: stable@vger.kernel.org Reported-and-Tested-by: Mark Moseley <moseleymark@gmail.com> Signed-off-by: Jeff Layton <jlayton@redhat.com> Signed-off-by: Steve French <smfrench@gmail.com>
2012-02-07cifs: request oplock when doing open on lookupJeff Layton
Currently, it's always set to 0 (no oplock requested). Cc: <stable@vger.kernel.org> Signed-off-by: Jeff Layton <jlayton@redhat.com> Signed-off-by: Steve French <smfrench@gmail.com>
2012-02-07cifs: fix error handling when cifscreds key payload is an errorJeff Layton
Reported-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Jeff Layton <jlayton@redhat.com> Signed-off-by: Steve French <smfrench@gmail.com>
2012-02-02cifs: Fix oops in session setup code for null user mountsShirish Pargaonkar
For null user mounts, do not invoke string length function during session setup. Cc: <stable@kernel.org Reported-and-Tested-by: Chris Clayton <chris2553@googlemail.com> Acked-by: Jeff Layton <jlayton@redhat.com> Signed-off-by: Shirish Pargaonkar <shirishpargaonkar@gmail.com> Signed-off-by: Steve French <smfrench@gmail.com>
2012-01-31[CIFS] Update cifs Kconfig title to match removal of experimental dependencySteve French
Removed the dependency on CONFIG_EXPERIMENTAL but forgot to update the text description to be consistent. Signed-off-by: Steve French <smfrench@gmail.com>
2012-01-31cifs: fix printk format warningsRandy Dunlap
Fix printk format warnings for ssize_t variables: fs/cifs/connect.c:2145:3: warning: format '%ld' expects type 'long int', but argument 3 has type 'ssize_t' fs/cifs/connect.c:2152:3: warning: format '%ld' expects type 'long int', but argument 3 has type 'ssize_t' fs/cifs/connect.c:2160:3: warning: format '%ld' expects type 'long int', but argument 3 has type 'ssize_t' fs/cifs/connect.c:2170:3: warning: format '%ld' expects type 'long int', but argument 3 has type 'ssize_t' Signed-off-by: Randy Dunlap <rdunlap@xenotime.net> Acked-by: Jeff Layton <jlayton@redhat.com> Cc: linux-cifs@vger.kernel.org
2012-01-31cifs: check offset in decode_ntlmssp_challenge()Dan Carpenter
We should check that we're not copying memory from beyond the end of the blob. Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Reviewed-by: Jeff Layton <jlayton@redhat.com>
2012-01-24cifs: NULL dereference on allocation failureDan Carpenter
We should just return directly here, the goto causes a NULL dereference. Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Reviewed-by: Jeff Layton <jlayton@redhat.com> Signed-off-by: Steve French <smfrench@gmail.com>
2012-01-18CIFS: Rename *UCS* functions to *UTF16*Steve French
to reflect the unicode encoding used by CIFS protocol. Signed-off-by: Pavel Shilovsky <piastry@etersoft.ru> Acked-by: Jeff Layton <jlayton@samba.org> Reviewed-by: Shirish Pargaonkar <shirishpargaonkar@gmail.com>
2012-01-18[CIFS] ACL and FSCACHE support no longer EXPERIMENTALSteve French
CIFS ACL support and FSCACHE support have been in long enough to be no longer considered experimental. Remove obsolete Kconfig dependency. Signed-off-by: Steve French <sfrench@us.ibm.com> Acked-by: Jeff Layton <jlayton@redhat.com>
2012-01-18[CIFS] Fix build break with multiuser patch when LANMAN disabledSteve French
CC: Jeff Layton <jlayton@redhat.com> Signed-off-by: Steve French <sfrench@us.ibm.com>
2012-01-17cifs: warn about impending deprecation of legacy MultiuserMount codeJeff Layton
We'll allow a grace period of 2 releases (3.3 and 3.4) and then remove the legacy code in 3.5. Signed-off-by: Jeff Layton <jlayton@redhat.com> Signed-off-by: Steve French <smfrench@gmail.com>
2012-01-17cifs: fetch credentials out of keyring for non-krb5 auth multiuser mountsJeff Layton
Fix up multiuser mounts to set the secType and set the username and password from the key payload in the vol info for non-krb5 auth types. Look for a key of type "secret" with a description of "cifs:a:<server address>" or "cifs:d:<domainname>". If that's found, then scrape the username and password out of the key payload and use that to create a new user session. Finally, don't have the code enforce krb5 auth on multiuser mounts, but do require a kernel with keys support. Signed-off-by: Jeff Layton <jlayton@redhat.com> Signed-off-by: Steve French <smfrench@gmail.com>
2012-01-17cifs: sanitize username handlingJeff Layton
Currently, it's not very clear whether you're allowed to have a NULL vol->username or ses->user_name. Some places check for it and some don't. Make it clear that a NULL pointer is OK in these fields, and ensure that all the callers check for that. Signed-off-by: Jeff Layton <jlayton@redhat.com> Signed-off-by: Steve French <smfrench@gmail.com>
2012-01-17cifs: lower default wsize when unix extensions are not usedJeff Layton
We've had some reports of servers (namely, the Solaris in-kernel CIFS server) that don't deal properly with writes that are "too large" even though they set CAP_LARGE_WRITE_ANDX. Change the default to better mirror what windows clients do. Cc: stable@vger.kernel.org Cc: Pavel Shilovsky <piastry@etersoft.ru> Reported-by: Nick Davis <phireph0x@yahoo.com> Signed-off-by: Jeff Layton <jlayton@redhat.com> Signed-off-by: Steve French <smfrench@gmail.com>
2012-01-17cifs: better instrumentation for coalesce_t2Jeff Layton
When coalesce_t2 returns an error, have it throw a cFYI message that explains the reason. Also rename some variables to clarify what they represent. Reported-and-Tested-by: Konstantinos Skarlatos <k.skarlatos@gmail.com> Signed-off-by: Jeff Layton <jlayton@redhat.com> Signed-off-by: Steve French <smfrench@gmail.com>
2012-01-12cifs: integer overflow in parse_dacl()Dan Carpenter
On 32 bit systems num_aces * sizeof(struct cifs_ace *) could overflow leading to a smaller ppace buffer than we expected. Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Acked-by: Jeff Layton <jlayton@samba.org> Signed-off-by: Steve French <smfrench@gmail.com>
2012-01-08Merge branch 'for-linus2' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs * 'for-linus2' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (165 commits) reiserfs: Properly display mount options in /proc/mounts vfs: prevent remount read-only if pending removes vfs: count unlinked inodes vfs: protect remounting superblock read-only vfs: keep list of mounts for each superblock vfs: switch ->show_options() to struct dentry * vfs: switch ->show_path() to struct dentry * vfs: switch ->show_devname() to struct dentry * vfs: switch ->show_stats to struct dentry * switch security_path_chmod() to struct path * vfs: prefer ->dentry->d_sb to ->mnt->mnt_sb vfs: trim includes a bit switch mnt_namespace ->root to struct mount vfs: take /proc/*/mounts and friends to fs/proc_namespace.c vfs: opencode mntget() mnt_set_mountpoint() vfs: spread struct mount - remaining argument of next_mnt() vfs: move fsnotify junk to struct mount vfs: move mnt_devname vfs: move mnt_list to struct mount vfs: switch pnode.h macros to struct mount * ...
2012-01-06vfs: switch ->show_options() to struct dentry *Al Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-01-06vfs: switch ->show_stats to struct dentry *Al Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-01-04[CIFS] default ntlmv2 for cifs mount delayed to 3.3Steve French
Turned out the ntlmv2 (default security authentication) upgrade was harder to test than expected, and we ran out of time to test against Apple and a few other servers that we wanted to. Delay upgrade of default security from ntlm to ntlmv2 (on mount) to 3.3. Still works fine to specify it explicitly via "sec=ntlmv2" so this should be fine. Acked-by: Jeff Layton <jlayton@samba.org> Signed-off-by: Steve French <smfrench@gmail.com>
2012-01-03cifs: propagate umode_tAl Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-01-03switch ->mknod() to umode_tAl Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-01-03switch ->create() to umode_tAl Viro
vfs_create() ignores everything outside of 16bit subset of its mode argument; switching it to umode_t is obviously equivalent and it's the only caller of the method Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-01-03switch vfs_mkdir() and ->mkdir() to umode_tAl Viro
vfs_mkdir() gets int, but immediately drops everything that might not fit into umode_t and that's the only caller of ->mkdir()... Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-01-03cifs: fix bad buffer length check in coalesce_t2Jeff Layton
The current check looks to see if the RFC1002 length is larger than CIFSMaxBufSize, and fails if it is. The buffer is actually larger than that by MAX_CIFS_HDR_SIZE. This bug has been around for a long time, but the fact that we used to cap the clients MaxBufferSize at the same level as the server tended to paper over it. Commit c974befa changed that however and caused this bug to bite in more cases. Reported-and-Tested-by: Konstantinos Skarlatos <k.skarlatos@gmail.com> Tested-by: Shirish Pargaonkar <shirishpargaonkar@gmail.com> Signed-off-by: Jeff Layton <jlayton@redhat.com> Signed-off-by: Steve French <smfrench@gmail.com>
2011-12-08cifs: check for NULL last_entry before calling cifs_save_resume_keyJeff Layton
Prior to commit eaf35b1, cifs_save_resume_key had some NULL pointer checks at the top. It turns out that at least one of those NULL pointer checks is needed after all. When the LastNameOffset in a FIND reply appears to be beyond the end of the buffer, CIFSFindFirst and CIFSFindNext will set srch_inf.last_entry to NULL. Since eaf35b1, the code will now oops in this situation. Fix this by having the callers check for a NULL last entry pointer before calling cifs_save_resume_key. No change is needed for the call site in cifs_readdir as it's not reachable with a NULL current_entry pointer. This should fix: https://bugzilla.redhat.com/show_bug.cgi?id=750247 Cc: stable@vger.kernel.org Cc: Christoph Hellwig <hch@infradead.org> Reported-by: Adam G. Metzler <adamgmetzler@gmail.com> Signed-off-by: Jeff Layton <jlayton@redhat.com> Signed-off-by: Steve French <smfrench@gmail.com>
2011-12-08cifs: attempt to freeze while looping on a receive attemptJeff Layton
In the recent overhaul of the demultiplex thread receive path, I neglected to ensure that we attempt to freeze on each pass through the receive loop. Reported-and-Tested-by: Woody Suwalski <terraluna977@gmail.com> Reported-and-Tested-by: Adam Williamson <awilliam@redhat.com> Signed-off-by: Jeff Layton <jlayton@redhat.com> Signed-off-by: Steve French <smfrench@gmail.com>
2011-12-08cifs: Fix sparse warning when calling cifs_strtoUCSSteve French
Fix sparse endian check warning while calling cifs_strtoUCS CHECK fs/cifs/smbencrypt.c fs/cifs/smbencrypt.c:216:37: warning: incorrect type in argument 1 (different base types) fs/cifs/smbencrypt.c:216:37: expected restricted __le16 [usertype] *<noident> fs/cifs/smbencrypt.c:216:37: got unsigned short *<noident> Signed-off-by: Steve French <smfrench@gmail.com> Acked-by: Shirish Pargaonkar <shirishpargaonkar@gmail.com
2011-12-08CIFS: Add descriptions to the brlock cache functionsPavel Shilovsky
Signed-off-by: Pavel Shilovsky <piastry@etersoft.ru> Signed-off-by: Steve French <sfrench@us.ibm.com>
2011-11-07Merge git://git.samba.org/sfrench/cifs-2.6Linus Torvalds
* git://git.samba.org/sfrench/cifs-2.6: CIFS: Cleanup byte-range locking code style CIFS: Simplify setlk error handling for mandatory locking
2011-11-06Merge branch 'modsplit-Oct31_2011' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/paulg/linux * 'modsplit-Oct31_2011' of git://git.kernel.org/pub/scm/linux/kernel/git/paulg/linux: (230 commits) Revert "tracing: Include module.h in define_trace.h" irq: don't put module.h into irq.h for tracking irqgen modules. bluetooth: macroize two small inlines to avoid module.h ip_vs.h: fix implicit use of module_get/module_put from module.h nf_conntrack.h: fix up fallout from implicit moduleparam.h presence include: replace linux/module.h with "struct module" wherever possible include: convert various register fcns to macros to avoid include chaining crypto.h: remove unused crypto_tfm_alg_modname() inline uwb.h: fix implicit use of asm/page.h for PAGE_SIZE pm_runtime.h: explicitly requires notifier.h linux/dmaengine.h: fix implicit use of bitmap.h and asm/page.h miscdevice.h: fix up implicit use of lists and types stop_machine.h: fix implicit use of smp.h for smp_processor_id of: fix implicit use of errno.h in include/linux/of.h of_platform.h: delete needless include <linux/module.h> acpi: remove module.h include from platform/aclinux.h miscdevice.h: delete unnecessary inclusion of module.h device_cgroup.h: delete needless include <linux/module.h> net: sch_generic remove redundant use of <linux/module.h> net: inet_timewait_sock doesnt need <linux/module.h> ... Fix up trivial conflicts (other header files, and removal of the ab3550 mfd driver) in - drivers/media/dvb/frontends/dibx000_common.c - drivers/media/video/{mt9m111.c,ov6650.c} - drivers/mfd/ab3550-core.c - include/linux/dmaengine.h
2011-11-04CIFS: Cleanup byte-range locking code stylePavel Shilovsky
Reorder parms of cifs_lock_init, trivially simplify getlk code and remove extra {} in cifs_lock_add_if. Cc: Dan Carpenter <dan.carpenter@oracle.com> Acked-by: Jeff Layton <jlayton@samba.org> Signed-off-by: Pavel Shilovsky <piastry@etersoft.ru> Signed-off-by: Steve French <sfrench@us.ibm.com>
2011-11-04CIFS: Simplify setlk error handling for mandatory lockingPavel Shilovsky
Now we allocate a lock structure at first, then we request to the server and save the lock if server returned OK though void function - it prevents the situation when we locked a file on the server and then return -ENOMEM from setlk. Signed-off-by: Pavel Shilovsky <piastry@etersoft.ru> Acked-by: Jeff Layton <jlayton@samba.org> Signed-off-by: Steve French <sfrench@us.ibm.com>
2011-11-03Merge git://git.samba.org/sfrench/cifs-2.6Linus Torvalds
* git://git.samba.org/sfrench/cifs-2.6: cifs: Assume passwords are encoded according to iocharset (try #2) CIFS: Fix the VFS brlock cache usage in posix locking case [CIFS] Update cifs version to 1.76 CIFS: Remove extra mutex_unlock in cifs_lock_add_if
2011-11-02filesystems: add set_nlink()Miklos Szeredi
Replace remaining direct i_nlink updates with a new set_nlink() updater function. Signed-off-by: Miklos Szeredi <mszeredi@suse.cz> Tested-by: Toshiyuki Okajima <toshi.okajima@jp.fujitsu.com> Signed-off-by: Christoph Hellwig <hch@lst.de>
2011-11-02filesystems: add missing nlink wrappersMiklos Szeredi
Replace direct i_nlink updates with the respective updater function (inc_nlink, drop_nlink, clear_nlink, inode_dec_link_count). Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
2011-10-31fs: add module.h to files that were implicitly using itPaul Gortmaker
Some files were using the complete module.h infrastructure without actually including the header at all. Fix them up in advance so once the implicit presence is removed, we won't get failures like this: CC [M] fs/nfsd/nfssvc.o fs/nfsd/nfssvc.c: In function 'nfsd_create_serv': fs/nfsd/nfssvc.c:335: error: 'THIS_MODULE' undeclared (first use in this function) fs/nfsd/nfssvc.c:335: error: (Each undeclared identifier is reported only once fs/nfsd/nfssvc.c:335: error: for each function it appears in.) fs/nfsd/nfssvc.c: In function 'nfsd': fs/nfsd/nfssvc.c:555: error: implicit declaration of function 'module_put_and_exit' make[3]: *** [fs/nfsd/nfssvc.o] Error 1 Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2011-10-29cifs: Assume passwords are encoded according to iocharset (try #2)Shirish Pargaonkar
Re-posting a patch originally posted by Oskar Liljeblad after rebasing on 3.2. Modify cifs to assume that the supplied password is encoded according to iocharset. Before this patch passwords would be treated as raw 8-bit data, which made authentication with Unicode passwords impossible (at least passwords with characters > 0xFF). The previous code would as a side effect accept passwords encoded with ISO 8859-1, since Unicode < 0x100 basically is ISO 8859-1. Software which relies on that will no longer support password chars > 0x7F unless it also uses iocharset=iso8859-1. (mount.cifs does not care about the encoding so it will work as expected.) Signed-off-by: Oskar Liljeblad <oskar@osk.mine.nu> Signed-off-by: Shirish Pargaonkar <shirishpargaonkar@gmail.com> Reviewed-by: Pavel Shilovsky <piastry@etersoft.ru> Tested-by: A <nimbus1_03087@yahoo.com> Signed-off-by: Steve French <smfrench@gmail.com>
2011-10-29CIFS: Fix the VFS brlock cache usage in posix locking casePavel Shilovsky
Request to the cache in FL_POSIX case only. Signed-off-by: Pavel Shilovsky <piastry@etersoft.ru> Signed-off-by: Steve French <smfrench@gmail.com>
2011-10-28[CIFS] Update cifs version to 1.76Steve French
Update cifs version to 1.76 now that async read, lock caching, and changes to oplock enabled interface are in. Thanks to Pavel for reminding me. Reviewed-by: Pavel Shilovsky <piastry@etersoft.ru> Signed-off-by: Steve French <smfrench@gmail.com>
2011-10-28CIFS: Remove extra mutex_unlock in cifs_lock_add_ifPavel Shilovsky
to prevent the mutex being unlocked twice if we interrupt a blocked lock. Signed-off-by: Pavel Shilovsky <piastry@etersoft.ru> Signed-off-by: Steve French <smfrench@gmail.com>
2011-10-28Merge branch 'for-next' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/hch/vfs-queue * 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/hch/vfs-queue: (21 commits) leases: fix write-open/read-lease race nfs: drop unnecessary locking in llseek ext4: replace cut'n'pasted llseek code with generic_file_llseek_size vfs: add generic_file_llseek_size vfs: do (nearly) lockless generic_file_llseek direct-io: merge direct_io_walker into __blockdev_direct_IO direct-io: inline the complete submission path direct-io: separate map_bh from dio direct-io: use a slab cache for struct dio direct-io: rearrange fields in dio/dio_submit to avoid holes direct-io: fix a wrong comment direct-io: separate fields only used in the submission path from struct dio vfs: fix spinning prevention in prune_icache_sb vfs: add a comment to inode_permission() vfs: pass all mask flags check_acl and posix_acl_permission vfs: add hex format for MAY_* flag values vfs: indicate that the permission functions take all the MAY_* flags compat: sync compat_stats with statfs. vfs: add "device" tag to /proc/self/mountstats cleanup: vfs: small comment fix for block_invalidatepage ... Fix up trivial conflict in fs/gfs2/file.c (llseek changes)
2011-10-28Merge branch '3.2-without-smb2' of git://git.samba.org/sfrench/cifs-2.6Linus Torvalds
* '3.2-without-smb2' of git://git.samba.org/sfrench/cifs-2.6: (52 commits) Fix build break when freezer not configured Add definition for share encryption CIFS: Make cifs_push_locks send as many locks at once as possible CIFS: Send as many mandatory unlock ranges at once as possible CIFS: Implement caching mechanism for posix brlocks CIFS: Implement caching mechanism for mandatory brlocks CIFS: Fix DFS handling in cifs_get_file_info CIFS: Fix error handling in cifs_readv_complete [CIFS] Fixup trivial checkpatch warning [CIFS] Show nostrictsync and noperm mount options in /proc/mounts cifs, freezer: add wait_event_freezekillable and have cifs use it cifs: allow cifs_max_pending to be readable under /sys/module/cifs/parameters cifs: tune bdi.ra_pages in accordance with the rsize cifs: allow for larger rsize= options and change defaults cifs: convert cifs_readpages to use async reads cifs: add cifs_async_readv cifs: fix protocol definition for READ_RSP cifs: add a callback function to receive the rest of the frame cifs: break out 3rd receive phase into separate function cifs: find mid earlier in receive codepath ...
2011-10-28vfs: do (nearly) lockless generic_file_llseekAndi Kleen
The i_mutex lock use of generic _file_llseek hurts. Independent processes accessing the same file synchronize over a single lock, even though they have no need for synchronization at all. Under high utilization this can cause llseek to scale very poorly on larger systems. This patch does some rethinking of the llseek locking model: First the 64bit f_pos is not necessarily atomic without locks on 32bit systems. This can already cause races with read() today. This was discussed on linux-kernel in the past and deemed acceptable. The patch does not change that. Let's look at the different seek variants: SEEK_SET: Doesn't really need any locking. If there's a race one writer wins, the other loses. For 32bit the non atomic update races against read() stay the same. Without a lock they can also happen against write() now. The read() race was deemed acceptable in past discussions, and I think if it's ok for read it's ok for write too. => Don't need a lock. SEEK_END: This behaves like SEEK_SET plus it reads the maximum size too. Reading the maximum size would have the 32bit atomic problem. But luckily we already have a way to read the maximum size without locking (i_size_read), so we can just use that instead. Without i_mutex there is no synchronization with write() anymore, however since the write() update is atomic on 64bit it just behaves like another racy SEEK_SET. On non atomic 32bit it's the same as SEEK_SET. => Don't need a lock, but need to use i_size_read() SEEK_CUR: This has a read-modify-write race window on the same file. One could argue that any application doing unsynchronized seeks on the same file is already broken. But for the sake of not adding a regression here I'm using the file->f_lock to synchronize this. Using this lock is much better than the inode mutex because it doesn't synchronize between processes. => So still need a lock, but can use a f_lock. This patch implements this new scheme in generic_file_llseek. I dropped generic_file_llseek_unlocked and changed all callers. Signed-off-by: Andi Kleen <ak@linux.intel.com> Signed-off-by: Christoph Hellwig <hch@lst.de>
2011-10-27Add definition for share encryptionSteve French
Samba supports a setfs info level to negotiate encrypted shares. This patch adds the defines so we recognize this info level. Later patches will add the enablement for it. Acked-by: Jeremy Allison <jra@samba.org> Signed-off-by: Steve French <smfrench@gmail.com>