aboutsummaryrefslogtreecommitdiffstats
path: root/fs/ecryptfs (follow)
AgeCommit message (Collapse)AuthorFilesLines
2011-05-29eCryptfs: Remove ecryptfs_header_cache_2Tyler Hicks3-13/+6
Now that ecryptfs_lookup_interpose() is no longer using ecryptfs_header_cache_2 to read in metadata, the kmem_cache can be removed and the ecryptfs_header_cache_1 kmem_cache can be renamed to ecryptfs_header_cache. Signed-off-by: Tyler Hicks <tyhicks@linux.vnet.ibm.com>
2011-05-29eCryptfs: Cleanup and optimize ecryptfs_lookup_interpose()Tyler Hicks3-105/+88
ecryptfs_lookup_interpose() has turned into spaghetti code over the years. This is an effort to clean it up. - Shorten overly descriptive variable names such as ecryptfs_dentry - Simplify gotos and error paths - Create helper function for reading plaintext i_size from metadata It also includes an optimization when reading i_size from the metadata. A complete page-sized kmem_cache_alloc() was being done to read in 16 bytes of metadata. The buffer for that is now statically declared. Signed-off-by: Tyler Hicks <tyhicks@linux.vnet.ibm.com>
2011-05-29eCryptfs: Return useful code from contains_ecryptfs_markerTyler Hicks1-16/+10
Instead of having the calling functions translate the true/false return code to either 0 or -EINVAL, have contains_ecryptfs_marker() return 0 or -EINVAL so that the calling functions can just reuse the return code. Also, rename the function to ecryptfs_validate_marker() to avoid callers mistakenly thinking that it returns true/false codes. Signed-off-by: Tyler Hicks <tyhicks@linux.vnet.ibm.com>
2011-05-29eCryptfs: Fix new inode race conditionTyler Hicks5-28/+30
Only unlock and d_add() new inodes after the plaintext inode size has been read from the lower filesystem. This fixes a race condition that was sometimes seen during a multi-job kernel build in an eCryptfs mount. https://bugzilla.kernel.org/show_bug.cgi?id=36002 Signed-off-by: Tyler Hicks <tyhicks@linux.vnet.ibm.com> Reported-by: David <david@unsolicited.net> Tested-by: David <david@unsolicited.net>
2011-05-29eCryptfs: Cleanup inode initialization codeTyler Hicks2-68/+69
The eCryptfs inode get, initialization, and dentry interposition code has two separate paths. One is for when dentry interposition is needed after doing things like a mkdir in the lower filesystem and the other is needed after a lookup. Unlocking new inodes and doing a d_add() needs to happen at different times, depending on which type of dentry interposing is being done. This patch cleans up the inode get and initialization code paths and splits them up so that the locking and d_add() differences mentioned above can be handled appropriately in a later patch. Signed-off-by: Tyler Hicks <tyhicks@linux.vnet.ibm.com> Tested-by: David <david@unsolicited.net>
2011-05-29eCryptfs: Consolidate inode functions into inode.cTyler Hicks4-107/+91
These functions should live in inode.c since their focus is on inodes and they're primarily used by functions in inode.c. Also does a simple cleanup of ecryptfs_inode_test() and rolls ecryptfs_init_inode() into ecryptfs_inode_set(). Signed-off-by: Tyler Hicks <tyhicks@linux.vnet.ibm.com> Tested-by: David <david@unsolicited.net>
2011-05-28Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6Linus Torvalds1-5/+0
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6: (36 commits) Cache xattr security drop check for write v2 fs: block_page_mkwrite should wait for writeback to finish mm: Wait for writeback when grabbing pages to begin a write configfs: remove unnecessary dentry_unhash on rmdir, dir rename fat: remove unnecessary dentry_unhash on rmdir, dir rename hpfs: remove unnecessary dentry_unhash on rmdir, dir rename minix: remove unnecessary dentry_unhash on rmdir, dir rename fuse: remove unnecessary dentry_unhash on rmdir, dir rename coda: remove unnecessary dentry_unhash on rmdir, dir rename afs: remove unnecessary dentry_unhash on rmdir, dir rename affs: remove unnecessary dentry_unhash on rmdir, dir rename 9p: remove unnecessary dentry_unhash on rmdir, dir rename ncpfs: fix rename over directory with dangling references ncpfs: document dentry_unhash usage ecryptfs: remove unnecessary dentry_unhash on rmdir, dir rename hostfs: remove unnecessary dentry_unhash on rmdir, dir rename hfsplus: remove unnecessary dentry_unhash on rmdir, dir rename hfs: remove unnecessary dentry_unhash on rmdir, dir rename omfs: remove unnecessary dentry_unhash on rmdir, dir rneame udf: remove unnecessary dentry_unhash from rmdir, dir rename ...
2011-05-28ecryptfs: remove unnecessary dentry_unhash on rmdir, dir renameSage Weil1-5/+0
ecryptfs does not have problems with references to unlinked directories. CC: Tyler Hicks <tyhicks@linux.vnet.ibm.com> CC: Dustin Kirkland <kirkland@canonical.com> CC: ecryptfs-devel@lists.launchpad.net Signed-off-by: Sage Weil <sage@newdream.net> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-05-27Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ecryptfs/ecryptfs-2.6Linus Torvalds2-25/+23
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ecryptfs/ecryptfs-2.6: MAINTAINERS: Update eCryptfs mailing list eCryptfs: Allow 2 scatterlist entries for encrypted filenames eCryptfs: Clear i_nlink in rmdir
2011-05-27eCryptfs: Allow 2 scatterlist entries for encrypted filenamesTyler Hicks1-25/+21
The buffers allocated while encrypting and decrypting long filenames can sometimes straddle two pages. In this situation, virt_to_scatterlist() will return -ENOMEM, causing the operation to fail and the user will get scary error messages in their logs: kernel: ecryptfs_write_tag_70_packet: Internal error whilst attempting to convert filename memory to scatterlist; expected rc = 1; got rc = [-12]. block_aligned_filename_size = [272] kernel: ecryptfs_encrypt_filename: Error attempting to generate tag 70 packet; rc = [-12] kernel: ecryptfs_encrypt_and_encode_filename: Error attempting to encrypt filename; rc = [-12] kernel: ecryptfs_lookup: Error attempting to encrypt and encode filename; rc = [-12] The solution is to allow up to 2 scatterlist entries to be used. Signed-off-by: Tyler Hicks <tyhicks@linux.vnet.ibm.com> Cc: <stable@kernel.org>
2011-05-27eCryptfs: Clear i_nlink in rmdirTyler Hicks1-0/+2
eCryptfs wasn't clearing the eCryptfs inode's i_nlink after a successful vfs_rmdir() on the lower directory. This resulted in the inode evict and destroy paths to be missed. https://bugs.launchpad.net/ecryptfs/+bug/723518 Signed-off-by: Tyler Hicks <tyhicks@linux.vnet.ibm.com> Cc: <stable@kernel.org>
2011-05-26vfs: push dentry_unhash on rename_dir into file systemsSage Weil1-0/+3
Only a few file systems need this. Start by pushing it down into each rename method (except gfs2 and xfs) so that it can be dealt with on a per-fs basis. Acked-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Sage Weil <sage@newdream.net> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-05-26vfs: push dentry_unhash on rmdir into file systemsSage Weil1-0/+2
Only a few file systems need this. Start by pushing it down into each fs rmdir method (except gfs2 and xfs) so it can be dealt with on a per-fs basis. This does not change behavior for any in-tree file systems. Acked-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Sage Weil <sage@newdream.net> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-04-25eCryptfs: Flush dirty pages in setattrTyler Hicks1-0/+6
After 57db4e8d73ef2b5e94a3f412108dff2576670a8a changed eCryptfs to write-back caching, eCryptfs page writeback updates the lower inode times due to the use of vfs_write() on the lower file. To preserve inode metadata changes, such as 'cp -p' does with utimensat(), we need to flush all dirty pages early in ecryptfs_setattr() so that the user-updated lower inode metadata isn't clobbered later in writeback. https://bugzilla.kernel.org/show_bug.cgi?id=33372 Reported-by: Rocko <rockorequin@hotmail.com> Signed-off-by: Tyler Hicks <tyhicks@linux.vnet.ibm.com>
2011-04-25eCryptfs: Handle failed metadata read in lookupTyler Hicks4-16/+28
When failing to read the lower file's crypto metadata during a lookup, eCryptfs must continue on without throwing an error. For example, there may be a plaintext file in the lower mount point that the user wants to delete through the eCryptfs mount. If an error is encountered while reading the metadata in lookup(), the eCryptfs inode's size could be incorrect. We must be sure to reread the plaintext inode size from the metadata when performing an open() or setattr(). The metadata is already being read in those paths, so this adds minimal performance overhead. This patch introduces a flag which will track whether or not the plaintext inode size has been read so that an incorrect i_size can be fixed in the open() or setattr() paths. https://bugs.launchpad.net/bugs/509180 Cc: <stable@kernel.org> Signed-off-by: Tyler Hicks <tyhicks@linux.vnet.ibm.com>
2011-04-25eCryptfs: Add reference counting to lower filesTyler Hicks6-59/+92
For any given lower inode, eCryptfs keeps only one lower file open and multiplexes all eCryptfs file operations through that lower file. The lower file was considered "persistent" and stayed open from the first lookup through the lifetime of the inode. This patch keeps the notion of a single, per-inode lower file, but adds reference counting around the lower file so that it is closed when not currently in use. If the reference count is at 0 when an operation (such as open, create, etc.) needs to use the lower file, a new lower file is opened. Since the file is no longer persistent, all references to the term persistent file are changed to lower file. Locking is added around the sections of code that opens the lower file and assign the pointer in the inode info, as well as the code the fputs the lower file when all eCryptfs users are done with it. This patch is needed to fix issues, when mounted on top of the NFSv3 client, where the lower file is left silly renamed until the eCryptfs inode is destroyed. Signed-off-by: Tyler Hicks <tyhicks@linux.vnet.ibm.com>
2011-04-25eCryptfs: dput dentries returned from dget_parentTyler Hicks1-2/+2
Call dput on the dentries previously returned by dget_parent() in ecryptfs_rename(). This is needed for supported eCryptfs mounts on top of the NFSv3 client. Signed-off-by: Tyler Hicks <tyhicks@linux.vnet.ibm.com>
2011-04-25eCryptfs: Remove extra d_delete in ecryptfs_rmdirTyler Hicks1-2/+0
vfs_rmdir() already calls d_delete() on the lower dentry. That was being duplicated in ecryptfs_rmdir() and caused a NULL pointer dereference when NFSv3 was the lower filesystem. Signed-off-by: Tyler Hicks <tyhicks@linux.vnet.ibm.com>
2011-03-31Fix common misspellingsLucas De Marchi1-2/+2
Fixes generated by 'codespell' and manually reviewed. Signed-off-by: Lucas De Marchi <lucas.demarchi@profusion.mobi>
2011-03-28eCryptfs: write lock requested keysRoberto Sassu2-7/+23
A requested key is write locked in order to prevent modifications on the authentication token while it is being used. Signed-off-by: Roberto Sassu <roberto.sassu@polito.it> Signed-off-by: Tyler Hicks <tyhicks@linux.vnet.ibm.com>
2011-03-28eCryptfs: move ecryptfs_find_auth_tok_for_sig() call before mutex_lockRoberto Sassu1-19/+19
The ecryptfs_find_auth_tok_for_sig() call is moved before the mutex_lock(s->tfm_mutex) instruction in order to avoid possible deadlocks that may occur by holding the lock on the two semaphores 'key->sem' and 's->tfm_mutex' in reverse order. Signed-off-by: Roberto Sassu <roberto.sassu@polito.it> Signed-off-by: Tyler Hicks <tyhicks@linux.vnet.ibm.com>
2011-03-28eCryptfs: verify authentication tokens before their useRoberto Sassu3-81/+135
Authentication tokens content may change if another requestor calls the update() method of the corresponding key. The new function ecryptfs_verify_auth_tok_from_key() retrieves the authentication token from the provided key and verifies if it is still valid before being used to encrypt or decrypt an eCryptfs file. Signed-off-by: Roberto Sassu <roberto.sassu@polito.it> [tyhicks: Minor formatting changes] Signed-off-by: Tyler Hicks <tyhicks@linux.vnet.ibm.com>
2011-03-28eCryptfs: modified size of keysig in the ecryptfs_key_sig structureRoberto Sassu2-1/+2
The size of the 'keysig' array is incremented of one byte in order to make room for the NULL character. The 'keysig' variable is used, in the function ecryptfs_generate_key_packet_set(), to find an authentication token with the given signature and is printed a debug message if it cannot be retrieved. Signed-off-by: Roberto Sassu <roberto.sassu@polito.it> Signed-off-by: Tyler Hicks <tyhicks@linux.vnet.ibm.com>
2011-03-28eCryptfs: removed num_global_auth_toks from ecryptfs_mount_crypt_statRoberto Sassu3-3/+0
This patch removes the 'num_global_auth_toks' field of the ecryptfs_mount_crypt_stat structure, used to count the number of items in the 'global_auth_tok_list' list. This variable is not needed because there are no checks based upon it. Signed-off-by: Roberto Sassu <roberto.sassu@polito.it> Signed-off-by: Tyler Hicks <tyhicks@linux.vnet.ibm.com>
2011-03-28eCryptfs: ecryptfs_keyring_auth_tok_for_sig() bug fixRoberto Sassu1-0/+1
The pointer '(*auth_tok_key)' is set to NULL in case request_key() fails, in order to prevent its use by functions calling ecryptfs_keyring_auth_tok_for_sig(). Signed-off-by: Roberto Sassu <roberto.sassu@polito.it> Cc: <stable@kernel.org> Signed-off-by: Tyler Hicks <tyhicks@linux.vnet.ibm.com>
2011-03-28eCryptfs: Unlock page in write_begin error pathTyler Hicks1-0/+5
Unlock the page in error path of ecryptfs_write_begin(). This may happen, for example, if decryption fails while bring the page up-to-date. Cc: <stable@kernel.org> Signed-off-by: Tyler Hicks <tyhicks@linux.vnet.ibm.com>
2011-03-28ecryptfs: modify write path to encrypt page in writepageThieu Le6-30/+38
Change the write path to encrypt the data only when the page is written to disk in ecryptfs_writepage. Previously, ecryptfs encrypts the page in ecryptfs_write_end which means that if there are multiple write requests to the same page, ecryptfs ends up re-encrypting that page over and over again. This patch minimizes the number of encryptions needed. Signed-off-by: Thieu Le <thieule@chromium.org> [tyhicks: Changed NULL .drop_inode sop pointer to generic_drop_inode] Signed-off-by: Tyler Hicks <tyhicks@linux.vnet.ibm.com>
2011-03-28eCryptfs: Remove ECRYPTFS_NEW_FILE crypt stat flagTyler Hicks3-27/+14
Now that grow_file() is not called in the ecryptfs_create() path, the ECRYPTFS_NEW_FILE flag is no longer needed. It helped ecryptfs_readpage() know not to decrypt zeroes that were read from the lower file in the grow_file() path. Signed-off-by: Tyler Hicks <tyhicks@linux.vnet.ibm.com>
2011-03-28eCryptfs: Remove unnecessary grow_file() functionTyler Hicks2-23/+1
When creating a new eCryptfs file, the crypto metadata is written out and then the lower file was being "grown" with 4 kB of encrypted zeroes. I suspect that growing the encrypted file was to prevent an information leak that the unencrypted file was empty. However, the unencrypted file size is stored, in plaintext, in the metadata so growing the file is unnecessary. Signed-off-by: Tyler Hicks <tyhicks@linux.vnet.ibm.com>
2011-02-21eCryptfs: Copy up lower inode attrs in getattrTyler Hicks1-0/+2
The lower filesystem may do some type of inode revalidation during a getattr call. eCryptfs should take advantage of that by copying the lower inode attributes to the eCryptfs inode after a call to vfs_getattr() on the lower inode. I originally wrote this fix while working on eCryptfs on nfsv3 support, but discovered it also fixed an eCryptfs on ext4 nanosecond timestamp bug that was reported. https://bugs.launchpad.net/bugs/613873 Cc: <stable@kernel.org> Signed-off-by: Tyler Hicks <tyhicks@linux.vnet.ibm.com>
2011-02-21ecryptfs: read on a directory should return EISDIR if not supportedAndy Whitcroft1-0/+1
read() calls against a file descriptor connected to a directory are incorrectly returning EINVAL rather than EISDIR: [EISDIR] [XSI] [Option Start] The fildes argument refers to a directory and the implementation does not allow the directory to be read using read() or pread(). The readdir() function should be used instead. [Option End] This occurs because we do not have a .read operation defined for ecryptfs directories. Connect this up to generic_read_dir(). BugLink: http://bugs.launchpad.net/bugs/719691 Signed-off-by: Andy Whitcroft <apw@canonical.com> Signed-off-by: Tyler Hicks <tyhicks@linux.vnet.ibm.com>
2011-02-21eCryptfs: Handle NULL nameidata pointersTyler Hicks3-26/+29
Allow for NULL nameidata pointers in eCryptfs create, lookup, and d_revalidate functions. Signed-off-by: Tyler Hicks <tyhicks@linux.vnet.ibm.com>
2011-02-17eCryptfs: Revert "dont call lookup_one_len to avoid NULL nameidata"Tyler Hicks1-94/+12
This reverts commit 21edad32205e97dc7ccb81a85234c77e760364c8 and commit 93c3fe40c279f002906ad14584c30671097d4394, which fixed a regression by the former. Al Viro pointed out bypassed dcache lookups in ecryptfs_new_lower_dentry(), misuse of vfs_path_lookup() in ecryptfs_lookup_one_lower() and a dislike of passing nameidata to the lower filesystem. Reported-by: Al Viro <viro@ZenIV.linux.org.uk> Signed-off-by: Tyler Hicks <tyhicks@linux.vnet.ibm.com>
2011-01-17ecryptfs: remove unnecessary decrypt when extending a fileFrank Swiderski1-8/+14
Removes an unecessary page decrypt from ecryptfs_begin_write when the page is beyond the current file size. Previously, the call to ecryptfs_decrypt_page would result in a read of 0 bytes, but still attempt to decrypt an entire page. This patch detects that case and merely zeros the page before marking it up-to-date. Signed-off-by: Frank Swiderski <fes@chromium.org> Signed-off-by: Tyler Hicks <tyhicks@linux.vnet.ibm.com>
2011-01-17ecryptfs: Fix ecryptfs_printk() size_t warningsTyler Hicks2-12/+12
Commit cb55d21f6fa19d8c6c2680d90317ce88c1f57269 revealed a number of missing 'z' length modifiers in calls to ecryptfs_printk() when printing variables of type size_t. This patch fixes those compiler warnings. Signed-off-by: Tyler Hicks <tyhicks@linux.vnet.ibm.com>
2011-01-17fs/ecryptfs: Add printf format/argument verification and fix falloutJoe Perches6-29/+30
Add __attribute__((format... to __ecryptfs_printk Make formats and arguments match. Add casts to (unsigned long long) for %llu. Signed-off-by: Joe Perches <joe@perches.com> [tyhicks: 80 columns cleanup and fixed typo] Signed-off-by: Tyler Hicks <tyhicks@linux.vnet.ibm.com>
2011-01-17ecryptfs: fixed testing of file descriptor flagsRoberto Sassu1-2/+2
This patch replaces the check (lower_file->f_flags & O_RDONLY) with ((lower_file & O_ACCMODE) == O_RDONLY). Signed-off-by: Roberto Sassu <roberto.sassu@polito.it> Signed-off-by: Tyler Hicks <tyhicks@linux.vnet.ibm.com>
2011-01-17ecryptfs: test lower_file pointer when lower_file_mutex is lockedRoberto Sassu2-27/+21
This patch prevents the lower_file pointer in the 'ecryptfs_inode_info' structure to be checked when the mutex 'lower_file_mutex' is not locked. Signed-off-by: Roberto Sassu <roberto.sassu@polito.it> Signed-off-by: Tyler Hicks <tyhicks@linux.vnet.ibm.com>
2011-01-17ecryptfs: missing initialization of the superblock 'magic' fieldRoberto Sassu1-0/+2
This patch initializes the 'magic' field of ecryptfs filesystems to ECRYPTFS_SUPER_MAGIC. Signed-off-by: Roberto Sassu <roberto.sassu@polito.it> [tyhicks: merge with 66cb76666d69] Signed-off-by: Tyler Hicks <tyhicks@linux.vnet.ibm.com>
2011-01-17ecryptfs: moved ECRYPTFS_SUPER_MAGIC definition to linux/magic.hRoberto Sassu1-1/+0
The definition of ECRYPTFS_SUPER_MAGIC has been moved to the include file 'linux/magic.h' to become available to other kernel subsystems. Signed-off-by: Roberto Sassu <roberto.sassu@polito.it> Signed-off-by: Tyler Hicks <tyhicks@linux.vnet.ibm.com>
2011-01-17ecryptfs: fix truncation error in ecryptfs_read_update_atimeEdward Shishkin1-1/+1
This is similar to the bug found in direct-io not so long ago. Fix up truncation (ssize_t->int). This only matters with >2G reads/writes, which the kernel doesn't permit. Signed-off-by: Edward Shishkin <edward.shishkin@gmail.com> Cc: Jeff Moyer <jmoyer@redhat.com> Cc: Christoph Hellwig <hch@infradead.org> Cc: Eric Sandeen <esandeen@redhat.com> Signed-off-by: Tyler Hicks <tyhicks@linux.vnet.ibm.com>
2011-01-13ecryptfs: fix broken buildLinus Torvalds1-3/+2
Stephen Rothwell reports that the vfs merge broke the build of ecryptfs. The breakage comes from commit 66cb76666d69 ("sanitize ecryptfs ->mount()") which was obviously not even build tested. Tssk, tssk, Al. This is the minimal build fixup for the situation, although I don't have a filesystem to actually test it with. Reported-by: Stephen Rothwell <sfr@canb.auug.org.au> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-01-12sanitize ecryptfs ->mount()Al Viro2-88/+68
kill ecryptfs_read_super(), reorder code allowing to use normal d_alloc_root() instead of opencoding it. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-01-07fs: provide rcu-walk aware permission i_opsNick Piggin1-1/+3
Signed-off-by: Nick Piggin <npiggin@kernel.dk>
2011-01-07fs: rcu-walk aware d_revalidate methodNick Piggin1-2/+7
Require filesystems be aware of .d_revalidate being called in rcu-walk mode (nd->flags & LOOKUP_RCU). For now do a simple push down, returning -ECHILD from all implementations. Signed-off-by: Nick Piggin <npiggin@kernel.dk>
2011-01-07fs: dcache reduce branches in lookup pathNick Piggin2-3/+3
Reduce some branches and memory accesses in dcache lookup by adding dentry flags to indicate common d_ops are set, rather than having to check them. This saves a pointer memory access (dentry->d_op) in common path lookup situations, and saves another pointer load and branch in cases where we have d_op but not the particular operation. Patched with: git grep -E '[.>]([[:space:]])*d_op([[:space:]])*=' | xargs sed -e 's/\([^\t ]*\)->d_op = \(.*\);/d_set_d_op(\1, \2);/' -e 's/\([^\t ]*\)\.d_op = \(.*\);/d_set_d_op(\&\1, \2);/' -i Signed-off-by: Nick Piggin <npiggin@kernel.dk>
2011-01-07fs: icache RCU free inodesNick Piggin1-1/+11
RCU free the struct inode. This will allow: - Subsequent store-free path walking patch. The inode must be consulted for permissions when walking, so an RCU inode reference is a must. - sb_inode_list_lock to be moved inside i_lock because sb list walkers who want to take i_lock no longer need to take sb_inode_list_lock to walk the list in the first place. This will simplify and optimize locking. - Could remove some nested trylock loops in dcache code - Could potentially simplify things a bit in VM land. Do not need to take the page lock to follow page->mapping. The downsides of this is the performance cost of using RCU. In a simple creat/unlink microbenchmark, performance drops by about 10% due to inability to reuse cache-hot slab objects. As iterations increase and RCU freeing starts kicking over, this increases to about 20%. In cases where inode lifetimes are longer (ie. many inodes may be allocated during the average life span of a single inode), a lot of this cache reuse is not applicable, so the regression caused by this patch is smaller. The cache-hot regression could largely be avoided by using SLAB_DESTROY_BY_RCU, however this adds some complexity to list walking and store-free path walking, so I prefer to implement this at a later date, if it is shown to be a win in real situations. I haven't found a regression in any non-micro benchmark so I doubt it will be a problem. Signed-off-by: Nick Piggin <npiggin@kernel.dk>
2011-01-07fs: dcache scale dentry refcountNick Piggin1-1/+1
Make d_count non-atomic and protect it with d_lock. This allows us to ensure a 0 refcount dentry remains 0 without dcache_lock. It is also fairly natural when we start protecting many other dentry members with d_lock. Signed-off-by: Nick Piggin <npiggin@kernel.dk>
2011-01-07fs: change d_hash for rcu-walkNick Piggin1-2/+2
Change d_hash so it may be called from lock-free RCU lookups. See similar patch for d_compare for details. For in-tree filesystems, this is just a mechanical change. Signed-off-by: Nick Piggin <npiggin@kernel.dk>
2010-11-17BKL: remove extraneous #include <smp_lock.h>Arnd Bergmann1-1/+0
The big kernel lock has been removed from all these files at some point, leaving only the #include. Remove this too as a cleanup. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Copyright © 1996 – 2023 Jason A. Donenfeld. All Rights Reverse Engineered.