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path: root/fs/ecryptfs/inode.c
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2012-09-14eCryptfs: Copy up attributes of the lower target inode after renameTyler Hicks
After calling into the lower filesystem to do a rename, the lower target inode's attributes were not copied up to the eCryptfs target inode. This resulted in the eCryptfs target inode staying around, rather than being evicted, because i_nlink was not updated for the eCryptfs inode. This also meant that eCryptfs didn't do the final iput() on the lower target inode so it stayed around, as well. This would result in a failure to free up space occupied by the target file in the rename() operation. Both target inodes would eventually be evicted when the eCryptfs filesystem was unmounted. This patch calls fsstack_copy_attr_all() after the lower filesystem does its ->rename() so that important inode attributes, such as i_nlink, are updated at the eCryptfs layer. ecryptfs_evict_inode() is now called and eCryptfs can drop its final reference on the lower inode. http://launchpad.net/bugs/561129 Signed-off-by: Tyler Hicks <tyhicks@canonical.com> Tested-by: Colin Ian King <colin.king@canonical.com> Cc: <stable@vger.kernel.org> [2.6.39+]
2012-08-02Merge tag 'ecryptfs-3.6-rc1-fixes' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tyhicks/ecryptfs Pull ecryptfs fixes from Tyler Hicks: - Fixes a bug when the lower filesystem mount options include 'acl', but the eCryptfs mount options do not - Cleanups in the messaging code - Better handling of empty files in the lower filesystem to improve usability. Failed file creations are now cleaned up and empty lower files are converted into eCryptfs during open(). - The write-through cache changes are being reverted due to bugs that are not easy to fix. Stability outweighs the performance enhancements here. - Improvement to the mount code to catch unsupported ciphers specified in the mount options * tag 'ecryptfs-3.6-rc1-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tyhicks/ecryptfs: eCryptfs: check for eCryptfs cipher support at mount eCryptfs: Revert to a writethrough cache model eCryptfs: Initialize empty lower files when opening them eCryptfs: Unlink lower inode when ecryptfs_create() fails eCryptfs: Make all miscdev functions use daemon ptr in file private_data eCryptfs: Remove unused messaging declarations and function eCryptfs: Copy up POSIX ACL and read-only flags from lower mount
2012-07-29ecryptfs_lookup_interpose(): allocate dentry_info firstAl Viro
less work on failure that way Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-07-29sanitize ecryptfs_lookup()Al Viro
* ->lookup() never gets hit with . or .. * dentry it gets is unhashed, so unless we had gone and hashed it ourselves, there's no need to d_drop() the sucker. * wrong name printed in one of the printks (NULL, in fact) Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-07-22don't expose I_NEW inodes via dentry->d_inodeAl Viro
d_instantiate(dentry, inode); unlock_new_inode(inode); is a bad idea; do it the other way round... Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-07-14don't pass nameidata * to vfs_create()Al Viro
all we want is a boolean flag, same as the method gets now Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-07-14don't pass nameidata to ->create()Al Viro
boolean "does it have to be exclusive?" flag is passed instead; Local filesystem should just ignore it - the object is guaranteed not to be there yet. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-07-14stop passing nameidata to ->lookup()Al Viro
Just the flags; only NFS cares even about that, but there are legitimate uses for such argument. And getting rid of that completely would require splitting ->lookup() into a couple of methods (at least), so let's leave that alone for now... Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-07-13eCryptfs: Revert to a writethrough cache modelTyler Hicks
A change was made about a year ago to get eCryptfs to better utilize its page cache during writes. The idea was to do the page encryption operations during page writeback, rather than doing them when initially writing into the page cache, to reduce the number of page encryption operations during sequential writes. This meant that the encrypted page would only be written to the lower filesystem during page writeback, which was a change from how eCryptfs had previously wrote to the lower filesystem in ecryptfs_write_end(). The change caused a few eCryptfs-internal bugs that were shook out. Unfortunately, more grave side effects have been identified that will force changes outside of eCryptfs. Because the lower filesystem isn't consulted until page writeback, eCryptfs has no way to pass lower write errors (ENOSPC, mainly) back to userspace. Additionaly, it was reported that quotas could be bypassed because of the way eCryptfs may sometimes open the lower filesystem using a privileged kthread. It would be nice to resolve the latest issues, but it is best if the eCryptfs commits be reverted to the old behavior in the meantime. This reverts: 32001d6f "eCryptfs: Flush file in vma close" 5be79de2 "eCryptfs: Flush dirty pages in setattr" 57db4e8d "ecryptfs: modify write path to encrypt page in writepage" Signed-off-by: Tyler Hicks <tyhicks@canonical.com> Tested-by: Colin King <colin.king@canonical.com> Cc: Colin King <colin.king@canonical.com> Cc: Thieu Le <thieule@google.com>
2012-07-08eCryptfs: Initialize empty lower files when opening themTyler Hicks
Historically, eCryptfs has only initialized lower files in the ecryptfs_create() path. Lower file initialization is the act of writing the cryptographic metadata from the inode's crypt_stat to the header of the file. The ecryptfs_open() path already expects that metadata to be in the header of the file. A number of users have reported empty lower files in beneath their eCryptfs mounts. Most of the causes for those empty files being left around have been addressed, but the presence of empty files causes problems due to the lack of proper cryptographic metadata. To transparently solve this problem, this patch initializes empty lower files in the ecryptfs_open() error path. If the metadata is unreadable due to the lower inode size being 0, plaintext passthrough support is not in use, and the metadata is stored in the header of the file (as opposed to the user.ecryptfs extended attribute), the lower file will be initialized. The number of nested conditionals in ecryptfs_open() was getting out of hand, so a helper function was created. To avoid the same nested conditional problem, the conditional logic was reversed inside of the helper function. https://launchpad.net/bugs/911507 Signed-off-by: Tyler Hicks <tyhicks@canonical.com> Cc: John Johansen <john.johansen@canonical.com> Cc: Colin Ian King <colin.king@canonical.com>
2012-07-08eCryptfs: Unlink lower inode when ecryptfs_create() failsTyler Hicks
ecryptfs_create() creates a lower inode, allocates an eCryptfs inode, initializes the eCryptfs inode and cryptographic metadata attached to the inode, and then writes the metadata to the header of the file. If an error was to occur after the lower inode was created, an empty lower file would be left in the lower filesystem. This is a problem because ecryptfs_open() refuses to open any lower files which do not have the appropriate metadata in the file header. This patch properly unlinks the lower inode when an error occurs in the later stages of ecryptfs_create(), reducing the chance that an empty lower file will be left in the lower filesystem. https://launchpad.net/bugs/872905 Signed-off-by: Tyler Hicks <tyhicks@canonical.com> Cc: John Johansen <john.johansen@canonical.com> Cc: Colin Ian King <colin.king@canonical.com>
2012-05-30get rid of pointless allocations and copying in ecryptfs_follow_link()Al Viro
switch to generic_readlink(), while we are at it Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-02-16eCryptfs: Copy up lower inode attrs after setting lower xattrTyler Hicks
After passing through a ->setxattr() call, eCryptfs needs to copy the inode attributes from the lower inode to the eCryptfs inode, as they may have changed in the lower filesystem's ->setxattr() path. One example is if an extended attribute containing a POSIX Access Control List is being set. The new ACL may cause the lower filesystem to modify the mode of the lower inode and the eCryptfs inode would need to be updated to reflect the new mode. https://launchpad.net/bugs/926292 Signed-off-by: Tyler Hicks <tyhicks@canonical.com> Reported-by: Sebastien Bacher <seb128@ubuntu.com> Cc: John Johansen <john.johansen@canonical.com> Cc: <stable@vger.kernel.org>
2012-01-25eCryptfs: Check inode changes in setattrTyler Hicks
Most filesystems call inode_change_ok() very early in ->setattr(), but eCryptfs didn't call it at all. It allowed the lower filesystem to make the call in its ->setattr() function. Then, eCryptfs would copy the appropriate inode attributes from the lower inode to the eCryptfs inode. This patch changes that and actually calls inode_change_ok() on the eCryptfs inode, fairly early in ecryptfs_setattr(). Ideally, the call would happen earlier in ecryptfs_setattr(), but there are some possible inode initialization steps that must happen first. Since the call was already being made on the lower inode, the change in functionality should be minimal, except for the case of a file extending truncate call. In that case, inode_newsize_ok() was never being called on the eCryptfs inode. Rather than inode_newsize_ok() catching maximum file size errors early on, eCryptfs would encrypt zeroed pages and write them to the lower filesystem until the lower filesystem's write path caught the error in generic_write_checks(). This patch introduces a new function, called ecryptfs_inode_newsize_ok(), which checks if the new lower file size is within the appropriate limits when the truncate operation will be growing the lower file. In summary this change prevents eCryptfs truncate operations (and the resulting page encryptions), which would exceed the lower filesystem limits or FSIZE rlimits, from ever starting. Signed-off-by: Tyler Hicks <tyhicks@canonical.com> Reviewed-by: Li Wang <liwang@nudt.edu.cn> Cc: <stable@vger.kernel.org>
2012-01-04fs: propagate umode_t, misc bitsAl Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-01-04kill ecryptfs_create_underlying_file()Al Viro
it's a just a wrapper for vfs_create() Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-01-04switch ->mknod() to umode_tAl Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-01-04switch ->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>
2012-01-04switch 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>
2011-11-23eCryptfs: Prevent file create race conditionTyler Hicks
The file creation path prematurely called d_instantiate() and unlock_new_inode() before the eCryptfs inode info was fully allocated and initialized and before the eCryptfs metadata was written to the lower file. This could result in race conditions in subsequent file and inode operations leading to unexpected error conditions or a null pointer dereference while attempting to use the unallocated memory. https://launchpad.net/bugs/813146 Signed-off-by: Tyler Hicks <tyhicks@canonical.com> Cc: stable@kernel.org
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>
2011-07-29ecryptfs: Make inode bdi consistent with superblock bdiThieu Le
Make the inode mapping bdi consistent with the superblock bdi so that dirty pages are flushed properly. Signed-off-by: Thieu Le <thieule@chromium.org> Cc: <stable@kernel.org> [2.6.39+] Signed-off-by: Tyler Hicks <tyhicks@linux.vnet.ibm.com>
2011-07-20don't pass nameidata to vfs_create() from ecryptfs_create()Al Viro
Instead of playing with removal of LOOKUP_OPEN, mangling (and restoring) nd->path, just pass NULL to vfs_create(). The whole point of what's being done there is to suppress any attempts to open file by underlying fs, which is what nd == NULL indicates. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-07-20ecryptfs_inode_permission() doesn't need to bail out on RCUAl Viro
... now that inode_permission() can take MAY_NOT_BLOCK and handle it properly. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-07-20->permission() sanitizing: don't pass flags to ->permission()Al Viro
not used by the instances anymore. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-05-29eCryptfs: Cleanup and optimize ecryptfs_lookup_interpose()Tyler Hicks
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: Fix new inode race conditionTyler Hicks
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 Hicks
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 Hicks
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 ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6 * '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 Weil
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 ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/ecryptfs/ecryptfs-2.6 * '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: Clear i_nlink in rmdirTyler Hicks
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 Weil
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 Weil
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 Hicks
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 Hicks
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 Hicks
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 Hicks
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 Hicks
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>
2011-03-28eCryptfs: Remove ECRYPTFS_NEW_FILE crypt stat flagTyler Hicks
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 Hicks
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 Hicks
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: Handle NULL nameidata pointersTyler Hicks
Allow for NULL nameidata pointers in eCryptfs create, lookup, and d_revalidate functions. Signed-off-by: Tyler Hicks <tyhicks@linux.vnet.ibm.com>
2011-02-18eCryptfs: Revert "dont call lookup_one_len to avoid NULL nameidata"Tyler Hicks
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: test lower_file pointer when lower_file_mutex is lockedRoberto Sassu
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>
2011-01-13sanitize ecryptfs ->mount()Al Viro
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 Piggin
Signed-off-by: Nick Piggin <npiggin@kernel.dk>
2011-01-07fs: dcache reduce branches in lookup pathNick Piggin
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: dcache scale dentry refcountNick Piggin
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>