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2009-12-019p: fix build breakage introduced by FS-CacheDavid Howells
While building 2.6.32-rc8-git2 for Fedora I noticed the following thinko in commit 201a15428bd54f83eccec8b7c64a04b8f9431204 ("FS-Cache: Handle pages pending storage that get evicted under OOM conditions"): fs/9p/cache.c: In function '__v9fs_fscache_release_page': fs/9p/cache.c:346: error: 'vnode' undeclared (first use in this function) fs/9p/cache.c:346: error: (Each undeclared identifier is reported only once fs/9p/cache.c:346: error: for each function it appears in.) make[2]: *** [fs/9p/cache.o] Error 1 Fix the 9P filesystem to correctly construct the argument to fscache_maybe_release_page(). Signed-off-by: Kyle McMartin <kyle@redhat.com> Signed-off-by: Xiaotian Feng <dfeng@redhat.com> [from identical patch] Signed-off-by: Stefan Lippers-Hollmann <s.l-h@gmx.de> [from identical patch] Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-11-19FS-Cache: Handle pages pending storage that get evicted under OOM conditionsDavid Howells
Handle netfs pages that the vmscan algorithm wants to evict from the pagecache under OOM conditions, but that are waiting for write to the cache. Under these conditions, vmscan calls the releasepage() function of the netfs, asking if a page can be discarded. The problem is typified by the following trace of a stuck process: kslowd005 D 0000000000000000 0 4253 2 0x00000080 ffff88001b14f370 0000000000000046 ffff880020d0d000 0000000000000007 0000000000000006 0000000000000001 ffff88001b14ffd8 ffff880020d0d2a8 000000000000ddf0 00000000000118c0 00000000000118c0 ffff880020d0d2a8 Call Trace: [<ffffffffa00782d8>] __fscache_wait_on_page_write+0x8b/0xa7 [fscache] [<ffffffff8104c0f1>] ? autoremove_wake_function+0x0/0x34 [<ffffffffa0078240>] ? __fscache_check_page_write+0x63/0x70 [fscache] [<ffffffffa00b671d>] nfs_fscache_release_page+0x4e/0xc4 [nfs] [<ffffffffa00927f0>] nfs_release_page+0x3c/0x41 [nfs] [<ffffffff810885d3>] try_to_release_page+0x32/0x3b [<ffffffff81093203>] shrink_page_list+0x316/0x4ac [<ffffffff8109372b>] shrink_inactive_list+0x392/0x67c [<ffffffff813532fa>] ? __mutex_unlock_slowpath+0x100/0x10b [<ffffffff81058df0>] ? trace_hardirqs_on_caller+0x10c/0x130 [<ffffffff8135330e>] ? mutex_unlock+0x9/0xb [<ffffffff81093aa2>] shrink_list+0x8d/0x8f [<ffffffff81093d1c>] shrink_zone+0x278/0x33c [<ffffffff81052d6c>] ? ktime_get_ts+0xad/0xba [<ffffffff81094b13>] try_to_free_pages+0x22e/0x392 [<ffffffff81091e24>] ? isolate_pages_global+0x0/0x212 [<ffffffff8108e743>] __alloc_pages_nodemask+0x3dc/0x5cf [<ffffffff81089529>] grab_cache_page_write_begin+0x65/0xaa [<ffffffff8110f8c0>] ext3_write_begin+0x78/0x1eb [<ffffffff81089ec5>] generic_file_buffered_write+0x109/0x28c [<ffffffff8103cb69>] ? current_fs_time+0x22/0x29 [<ffffffff8108a509>] __generic_file_aio_write+0x350/0x385 [<ffffffff8108a588>] ? generic_file_aio_write+0x4a/0xae [<ffffffff8108a59e>] generic_file_aio_write+0x60/0xae [<ffffffff810b2e82>] do_sync_write+0xe3/0x120 [<ffffffff8104c0f1>] ? autoremove_wake_function+0x0/0x34 [<ffffffff810b18e1>] ? __dentry_open+0x1a5/0x2b8 [<ffffffff810b1a76>] ? dentry_open+0x82/0x89 [<ffffffffa00e693c>] cachefiles_write_page+0x298/0x335 [cachefiles] [<ffffffffa0077147>] fscache_write_op+0x178/0x2c2 [fscache] [<ffffffffa0075656>] fscache_op_execute+0x7a/0xd1 [fscache] [<ffffffff81082093>] slow_work_execute+0x18f/0x2d1 [<ffffffff8108239a>] slow_work_thread+0x1c5/0x308 [<ffffffff8104c0f1>] ? autoremove_wake_function+0x0/0x34 [<ffffffff810821d5>] ? slow_work_thread+0x0/0x308 [<ffffffff8104be91>] kthread+0x7a/0x82 [<ffffffff8100beda>] child_rip+0xa/0x20 [<ffffffff8100b87c>] ? restore_args+0x0/0x30 [<ffffffff8102ef83>] ? tg_shares_up+0x171/0x227 [<ffffffff8104be17>] ? kthread+0x0/0x82 [<ffffffff8100bed0>] ? child_rip+0x0/0x20 In the above backtrace, the following is happening: (1) A page storage operation is being executed by a slow-work thread (fscache_write_op()). (2) FS-Cache farms the operation out to the cache to perform (cachefiles_write_page()). (3) CacheFiles is then calling Ext3 to perform the actual write, using Ext3's standard write (do_sync_write()) under KERNEL_DS directly from the netfs page. (4) However, for Ext3 to perform the write, it must allocate some memory, in particular, it must allocate at least one page cache page into which it can copy the data from the netfs page. (5) Under OOM conditions, the memory allocator can't immediately come up with a page, so it uses vmscan to find something to discard (try_to_free_pages()). (6) vmscan finds a clean netfs page it might be able to discard (possibly the one it's trying to write out). (7) The netfs is called to throw the page away (nfs_release_page()) - but it's called with __GFP_WAIT, so the netfs decides to wait for the store to complete (__fscache_wait_on_page_write()). (8) This blocks a slow-work processing thread - possibly against itself. The system ends up stuck because it can't write out any netfs pages to the cache without allocating more memory. To avoid this, we make FS-Cache cancel some writes that aren't in the middle of actually being performed. This means that some data won't make it into the cache this time. To support this, a new FS-Cache function is added fscache_maybe_release_page() that replaces what the netfs releasepage() functions used to do with respect to the cache. The decisions fscache_maybe_release_page() makes are counted and displayed through /proc/fs/fscache/stats on a line labelled "VmScan". There are four counters provided: "nos=N" - pages that weren't pending storage; "gon=N" - pages that were pending storage when we first looked, but weren't by the time we got the object lock; "bsy=N" - pages that we ignored as they were actively being written when we looked; and "can=N" - pages that we cancelled the storage of. What I'd really like to do is alter the behaviour of the cancellation heuristics, depending on how necessary it is to expel pages. If there are plenty of other pages that aren't waiting to be written to the cache that could be ejected first, then it would be nice to hold up on immediate cancellation of cache writes - but I don't see a way of doing that. Signed-off-by: David Howells <dhowells@redhat.com>
2009-11-029p: fix readdir corner casesEric Van Hensbergen
The patch below also addresses a couple of other corner cases in readdir seen with a large (e.g. 64k) msize. I'm not sure what people think of my co-opting of fid->aux here. I'd be happy to rework if there's a better way. When the size of the user supplied buffer passed to readdir is smaller than the data returned in one go by the 9P read request, v9fs_dir_readdir() currently discards extra data so that, on the next call, a 9P read request will be issued with offset < previous offset + bytes returned, which voilates the constraint described in paragraph 3 of read(5) description. This patch preseves the leftover data in fid->aux for use in the next call. Signed-off-by: Jim Garlick <garlick@llnl.gov> Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
2009-11-029p: fix readlinkMartin Stava
I do not know if you've looked on the patch, but unfortunately it is incorrect. A suggested better version is in this email (the old version didn't work in case the user provided buffer was not long enough - it incorrectly appended null byte on a position of last char, and thus broke the contract of the readlink method). However, I'm still not sure this is 100% correct thing to do, I think readlink is supposed to return buffer without last null byte in all cases, but we do return last null byte (even the old version).. on the other hand it is likely unspecified what is in the remaining part of the buffer, so null character may be fine there ;): Signed-off-by: Martin Stava <martin.stava@gmail.com> Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
2009-11-029p: fix a small bug in readdir for long directoriesMartin Stava
Here is a proposed patch for bug in readdir. Listing of dirs with many files fails without this patch. Signed-off-by: Martin Stava <martin.stava@gmail.com> Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
2009-09-239p: Add fscache support to 9pAbhishek Kulkarni
This patch adds a persistent, read-only caching facility for 9p clients using the FS-Cache caching backend. When the fscache facility is enabled, each inode is associated with a corresponding vcookie which is an index into the FS-Cache indexing tree. The FS-Cache indexing tree is indexed at 3 levels: - session object associated with each mount. - inode/vcookie - actual data (pages) A cache tag is chosen randomly for each session. These tags can be read off /sys/fs/9p/caches and can be passed as a mount-time parameter to re-attach to the specified caching session. Signed-off-by: Abhishek Kulkarni <adkulkar@umail.iu.edu> Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
2009-09-239p: Fix the incorrect update of inode size in v9fs_file_write()Abhishek Kulkarni
When using the cache=loose flags, the inode's size was not being updated correctly on a remote write. Thus subsequent reads of the whole file resulted in a truncated read. Fix it. Signed-off-by: Abhishek Kulkarni <adkulkar@umail.iu.edu> Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
2009-09-239p: Use the i_size_[read, write]() macros instead of using inode->i_size ↵Abhishek Kulkarni
directly. Change all occurrence of inode->i_size with i_size_read() or i_size_write() as appropriate. Signed-off-by: Abhishek Kulkarni <adkulkar@umail.iu.edu> Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
2009-08-179p: remove unnecessary v9fses->options which duplicates the mount stringAbhishek Kulkarni
The mount options string is saved in sb->s_options. This patch removes the redundant duplicating of the mount options. Also, since we are not displaying anything special in show options, we replace v9fs_show_options with generic_show_options for now. Signed-off-by: Abhishek Kulkarni <adkulkar@umail.iu.edu> Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
2009-08-179p: Add missing cast for the error return value in v9fs_get_inodeAbhishek Kulkarni
Cast the error return value (ENOMEM) in v9fs_get_inode() to its correct type using ERR_PTR. Signed-off-by: Abhishek Kulkarni <adkulkar@umail.iu.edu> Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
2009-08-179p: Remove redundant inode uid/gid assignmentAbhishek Kulkarni
Remove a redundant update of inode's i_uid and i_gid after v9fs_get_inode() since the latter already sets up a new inode and sets the proper uid and gid values. Signed-off-by: Abhishek Kulkarni <adkulkar@umail.iu.edu> Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
2009-08-179p: Fix possible regressions when ->get_sb fails.Abhishek Kulkarni
->get_sb can fail causing some badness. this patch fixes * clear sb->fs_s_info in kill_sb. * deactivate_locked_super() calls kill_sb (v9fs_kill_super) which closes the destroys the client, clunks all its fids and closes the v9fs session. Attempting to do it twice will cause an oops. Signed-off-by: Abhishek Kulkarni <adkulkar@umail.iu.edu> Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
2009-08-179p: Fix v9fs show_optionsAbhishek Kulkarni
Add the delimiter ',' before the options when they are passed and check if no option parameters are passed to prevent displaying NULL in /proc/mounts. Signed-off-by: Abhishek Kulkarni <adkulkar@umail.iu.edu> Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
2009-08-179p: Fix possible memleak in v9fs_inode_from fid.Abhishek Kulkarni
Add missing p9stat_free in v9fs_inode_from_fid to avoid any possible leaks. Signed-off-by: Abhishek Kulkarni <adkulkar@umail.iu.edu> Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
2009-08-179p: minor comment fixesAbhishek Kulkarni
Fix the comments -- mostly the improper and/or missing descriptions of function parameters. Signed-off-by: Abhishek Kulkarni <adkulkar@umail.iu.edu> Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
2009-08-179p: Fix possible inode leak in v9fs_get_inode.Abhishek Kulkarni
Add a missing iput when cleaning up if v9fs_get_inode fails after returning a valid inode. Signed-off-by: Abhishek Kulkarni <adkulkar@umail.iu.edu> Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
2009-08-179p: Check for error in return value of v9fs_fid_addAbhishek Kulkarni
Check if v9fs_fid_add was successful or not based on its return value. Signed-off-by: Abhishek Kulkarni <adkulkar@umail.iu.edu> Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
2009-07-149p: Fix incorrect parameters to v9fs_file_readn.Abhishek Kulkarni
Fix v9fs_vfs_readpage. The offset and size parameters to v9fs_file_readn were interchanged and hence passed incorrectly. Signed-off-by: Abhishek Kulkarni <adkulkar@umail.iu.edu> Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
2009-06-179P doesn't need BKL in ->umount_begin()Al Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-05-09Fix a leak in failure exit in 9p ->get_sb()Al Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-05-09Convert obvious places to deactivate_locked_super()Al Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-05-09vfs: umount_begin BKL pushdownAlessio Igor Bogani
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>
2009-03-27vfs: simple_set_mnt() should return voidSukadev Bhattiprolu
simple_set_mnt() is defined as returning 'int' but always returns 0. Callers assume simple_set_mnt() never fails and don't properly cleanup if it were to _ever_ fail. For instance, get_sb_single() and get_sb_nodev() should: up_write(sb->s_unmount); deactivate_super(sb); if simple_set_mnt() fails. Since simple_set_mnt() never fails, would be cleaner if it did not return anything. [akpm@linux-foundation.org: fix build] Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com> Acked-by: Serge Hallyn <serue@us.ibm.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Christoph Hellwig <hch@lst.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-03-27constify dentry_operations: 9pAl Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-01-22fs/Kconfig: move 9p outAlexey Dobriyan
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
2008-12-25Merge branch 'next' into for-linusJames Morris
2008-12-19fs/9p: change simple_strtol to simple_strtoulJulia Lawall
Since v9ses->uid is unsigned, it would seem better to use simple_strtoul that simple_strtol. A simplified version of the semantic patch that makes this change is as follows: (http://www.emn.fr/x-info/coccinelle/) // <smpl> @r2@ long e; position p; @@ e = simple_strtol@p(...) @@ position p != r2.p; type T; T e; @@ e = - simple_strtol@p + simple_strtoul (...) // </smpl> Signed-off-by: Julia Lawall <julia@diku.dk> Acked-by: Eric Van Hensbergen <ericvh@gmail.com>
2008-12-199p: convert d_iname references to d_name.nameWu Fengguang
d_iname is rubbish for long file names. Use d_name.name in printks instead. Signed-off-by: Wu Fengguang <wfg@linux.intel.com> Acked-by: Eric Van Hensbergen <ericvh@gmail.com>
2008-12-199p: Remove potentially bad parameter from function entry debug print.Duane Griffin
Signed-off-by: Duane Griffin <duaneg@dghda.com> Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
2008-11-14CRED: Wrap task credential accesses in 9P2000 filesystemDavid Howells
Wrap access to task credentials so that they can be separated more easily from the task_struct during the introduction of COW creds. Change most current->(|e|s|fs)[ug]id to current_(|e|s|fs)[ug]id(). Change some task->e?[ug]id to task_e?[ug]id(). In some places it makes more sense to use RCU directly rather than a convenient wrapper; these will be addressed by later patches. Signed-off-by: David Howells <dhowells@redhat.com> Reviewed-by: James Morris <jmorris@namei.org> Acked-by: Serge Hallyn <serue@us.ibm.com> Reviewed-by: Eric Van Hensbergen <ericvh@gmail.com> Cc: Ron Minnich <rminnich@sandia.gov> Cc: Latchesar Ionkov <lucho@ionkov.net> Cc: v9fs-developer@lists.sourceforge.net Signed-off-by: James Morris <jmorris@namei.org>
2008-10-229p: fix format warningEric Van Hensbergen
This patch fixes a format warning which appears on 64-bit builds. Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
2008-10-179p: fix device file handlingMagnus Deininger
In v9fs_get_inode(), for block, as well as char devices (in theory), the function init_special_inode() is called to set up callback functions for file ops. this function uses the file mode's value to determine whether to use block or char dev functions. In v9fs_inode_from_fid(), the function p9mode2unixmode() is used, but for all devices it initially returns S_IFBLK, then uses v9fs_get_inode() to initialise a new inode, then finally uses v9fs_stat2inode(), which would determine whether the inode is a block or character device. However, at that point init_special_inode() had already decided to use the block device functions, so even if the inode's mode is turned to a character device, the block functions are still used to operate on them. The attached patch simply calls init_special_inode() again for devices after parsing device node data in v9fs_stat2inode() so that the proper functions are used. Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
2008-10-179p: eliminate depricated conv functionsEric Van Hensbergen
Remove depricated conv functions which have been replaced with new protocol routines. This patch also reworks the one instance of the file-system code which directly calls conversion routines (to accomplish unpacking dirreads). Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
2008-10-179p: rework client code to use new protocol support functionsEric Van Hensbergen
Now that the new protocol functions are in place, this patch switches the client code to using the new support code. Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
2008-10-179p: move dirread to fs layerEric Van Hensbergen
Currently reading a directory is implemented in the client code. This function is not actually a wire operation, but a meta operation which calls read operations and processes the results. This patch moves this functionality to the fs layer and calls component wire operations instead of constructing their packets. This provides a cleaner separation and will help when we reorganize the client functions and protocol processing methods. Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
2008-10-179p: adjust 9p vfs write operationEric Van Hensbergen
Currently, the 9p net wire operation ensures that all data is sent by sending multiple packets if the data requested is larger than the msize. This is better handled in the vfs code so that we can simplify wire operations to being concerned with only putting data onto and taking data off of the wire. Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
2008-10-179p: move readn meta-function from client to fs layerEric Van Hensbergen
There are a couple of methods in the client code which aren't actually wire operations. To keep things organized cleaner, these operations are being moved to the fs layer. This patch moves the readn meta-function (which executes multiple wire reads until a buffer is full) to the fs layer. Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
2008-10-179p: consolidate read/write functionsEric Van Hensbergen
Currently there are two separate versions of read and write. One for dealing with user buffers and the other for dealing with kernel buffers. There is a tremendous amount of code duplication in the otherwise identical versions of these functions. This patch adds an additional user buffer parameter to read and write and conditionalizes handling of the buffer on whether the kernel buffer or the user buffer is populated. Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
2008-10-179p: consolidate transport structureEric Van Hensbergen
Right now there is a transport module structure which provides per-transport type functions and data and a transport structure which contains per-instance public data as well as function pointers to instance specific functions. This patch moves public transport visible instance data to the client structure (which in some cases had duplicate data) and consolidates the functions into the transport module structure. Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
2008-10-13vfs: Use const for kernel parser tableSteven Whitehouse
This is a much better version of a previous patch to make the parser tables constant. Rather than changing the typedef, we put the "const" in all the various places where its required, allowing the __initconst exception for nfsroot which was the cause of the previous trouble. This was posted for review some time ago and I believe its been in -mm since then. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com> Cc: Alexander Viro <aviro@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-09-249p: use an IS_ERR test rather than a NULL testJulien Brunel
In case of error, the function p9_client_walk returns an ERR pointer, but never returns a NULL pointer. So a NULL test that comes after an IS_ERR test should be deleted. The semantic match that finds this problem is as follows: (http://www.emn.fr/x-info/coccinelle/) // <smpl> @match_bad_null_test@ expression x, E; statement S1,S2; @@ x = p9_client_walk(...) ... when != x = E * if (x != NULL) S1 else S2 // </smpl> Signed-off-by: Julien Brunel <brunel@diku.dk> Signed-off-by: Julia Lawall <julia@diku.dk> Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2008-08-25[PATCH] fix ->llseek() for a bunch of directoriesAl Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2008-07-039p: fix O_APPEND in legacy modeEric Van Hensbergen
The legacy protocol's open operation doesn't handle an append operation (it is expected that the client take care of it). We were incorrectly passing the extended protocol's flag through even in legacy mode. This was reported in bugzilla report #10689. This patch fixes the problem by disallowing extended protocol open modes from being passed in legacy mode and implemented append functionality on the client side by adding a seek after the open. Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
2008-05-149p: fix error path during early mountEric Van Hensbergen
There was some cleanup issues during early mount which would trigger a kernel bug for certain types of failure. This patch reorganizes the cleanup to get rid of the bad behavior. This also merges the 9pnet and 9pnet_fd modules for the purpose of configuration and initialization. Keeping the fd transport separate from the core 9pnet code seemed like a good idea at the time, but in practice has caused more harm and confusion than good. Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
2008-05-14fs/9p/v9fs.c (v9fs_parse_options): Handle kstrdup and match_strdup failure. ↵Jim Meyering
Now that this function can fail, return an int, diagnose other option-parsing failures, and adjust the sole caller: (v9fs_session_init): Handle kstrdup failure. Propagate any new v9fs_parse_options failure "up". Signed-off-by: Jim Meyering <meyering@redhat.com> Cc: Ron Minnich <rminnich@sandia.gov> Cc: Latchesar Ionkov <lucho@ionkov.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: Eric Van Hensbergen <ericvh@gmail.com>
2008-05-149p: Documentation updatesEric Van Hensbergen
The kernel-doc comments of much of the 9p system have been in disarray since reorganization. This patch fixes those problems, adds additional documentation and a template book which collects the 9p information. Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
2008-05-14add match_strlcpy() us it to make v9fs make uname and remotename parsing ↵Markus Armbruster
more robust match_strcpy() is a somewhat creepy function: the caller needs to make sure that the destination buffer is big enough, and when he screws up or forgets, match_strcpy() happily overruns the buffer. There's exactly one customer: v9fs_parse_options(). I believe it currently can't overflow its buffer, but that's not exactly obvious. The source string is a substing of the mount options. The kernel silently truncates those to PAGE_SIZE bytes, including the terminating zero. See compat_sys_mount() and do_mount(). The destination buffer is obtained from __getname(), which allocates from name_cachep, which is initialized by vfs_caches_init() for size PATH_MAX. We're safe as long as PATH_MAX <= PAGE_SIZE. PATH_MAX is 4096. As far as I know, the smallest PAGE_SIZE is also 4096. Here's a patch that makes the code a bit more obviously correct. It doesn't depend on PATH_MAX <= PAGE_SIZE. Signed-off-by: Markus Armbruster <armbru@redhat.com> Cc: Latchesar Ionkov <lucho@ionkov.net> Cc: Jim Meyering <meyering@redhat.com> Cc: "Randy.Dunlap" <rdunlap@xenotime.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
2008-04-25[PATCH] restore sane ->umount_begin() APIAl Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2008-04-18fs: Remove unnecessary inclusions of asm/semaphore.hMatthew Wilcox
None of these files use any of the functionality promised by asm/semaphore.h. Signed-off-by: Matthew Wilcox <willy@linux.intel.com>
2008-02-07Convert ERR_PTR(PTR_ERR(p)) instances to ERR_CAST(p)David Howells
Convert instances of ERR_PTR(PTR_ERR(p)) to ERR_CAST(p) using: perl -spi -e 's/ERR_PTR[(]PTR_ERR[(](.*)[)][)]/ERR_CAST(\1)/' `grep -rl 'ERR_PTR[(]*PTR_ERR' fs crypto net security` Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>