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path: root/fs/ext4/acl.c
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2017-11-02License cleanup: add SPDX GPL-2.0 license identifier to files with no licenseGreg Kroah-Hartman
Many source files in the tree are missing licensing information, which makes it harder for compliance tools to determine the correct license. By default all files without license information are under the default license of the kernel, which is GPL version 2. Update the files which contain no license information with the 'GPL-2.0' SPDX license identifier. The SPDX identifier is a legally binding shorthand, which can be used instead of the full boiler plate text. This patch is based on work done by Thomas Gleixner and Kate Stewart and Philippe Ombredanne. How this work was done: Patches were generated and checked against linux-4.14-rc6 for a subset of the use cases: - file had no licensing information it it. - file was a */uapi/* one with no licensing information in it, - file was a */uapi/* one with existing licensing information, Further patches will be generated in subsequent months to fix up cases where non-standard license headers were used, and references to license had to be inferred by heuristics based on keywords. The analysis to determine which SPDX License Identifier to be applied to a file was done in a spreadsheet of side by side results from of the output of two independent scanners (ScanCode & Windriver) producing SPDX tag:value files created by Philippe Ombredanne. Philippe prepared the base worksheet, and did an initial spot review of a few 1000 files. The 4.13 kernel was the starting point of the analysis with 60,537 files assessed. Kate Stewart did a file by file comparison of the scanner results in the spreadsheet to determine which SPDX license identifier(s) to be applied to the file. She confirmed any determination that was not immediately clear with lawyers working with the Linux Foundation. Criteria used to select files for SPDX license identifier tagging was: - Files considered eligible had to be source code files. - Make and config files were included as candidates if they contained >5 lines of source - File already had some variant of a license header in it (even if <5 lines). All documentation files were explicitly excluded. The following heuristics were used to determine which SPDX license identifiers to apply. - when both scanners couldn't find any license traces, file was considered to have no license information in it, and the top level COPYING file license applied. For non */uapi/* files that summary was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 11139 and resulted in the first patch in this series. If that file was a */uapi/* path one, it was "GPL-2.0 WITH Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 WITH Linux-syscall-note 930 and resulted in the second patch in this series. - if a file had some form of licensing information in it, and was one of the */uapi/* ones, it was denoted with the Linux-syscall-note if any GPL family license was found in the file or had no licensing in it (per prior point). Results summary: SPDX license identifier # files ---------------------------------------------------|------ GPL-2.0 WITH Linux-syscall-note 270 GPL-2.0+ WITH Linux-syscall-note 169 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17 LGPL-2.1+ WITH Linux-syscall-note 15 GPL-1.0+ WITH Linux-syscall-note 14 ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5 LGPL-2.0+ WITH Linux-syscall-note 4 LGPL-2.1 WITH Linux-syscall-note 3 ((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3 ((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1 and that resulted in the third patch in this series. - when the two scanners agreed on the detected license(s), that became the concluded license(s). - when there was disagreement between the two scanners (one detected a license but the other didn't, or they both detected different licenses) a manual inspection of the file occurred. - In most cases a manual inspection of the information in the file resulted in a clear resolution of the license that should apply (and which scanner probably needed to revisit its heuristics). - When it was not immediately clear, the license identifier was confirmed with lawyers working with the Linux Foundation. - If there was any question as to the appropriate license identifier, the file was flagged for further research and to be revisited later in time. In total, over 70 hours of logged manual review was done on the spreadsheet to determine the SPDX license identifiers to apply to the source files by Kate, Philippe, Thomas and, in some cases, confirmation by lawyers working with the Linux Foundation. Kate also obtained a third independent scan of the 4.13 code base from FOSSology, and compared selected files where the other two scanners disagreed against that SPDX file, to see if there was new insights. The Windriver scanner is based on an older version of FOSSology in part, so they are related. Thomas did random spot checks in about 500 files from the spreadsheets for the uapi headers and agreed with SPDX license identifier in the files he inspected. For the non-uapi files Thomas did random spot checks in about 15000 files. In initial set of patches against 4.14-rc6, 3 files were found to have copy/paste license identifier errors, and have been fixed to reflect the correct identifier. Additionally Philippe spent 10 hours this week doing a detailed manual inspection and review of the 12,461 patched files from the initial patch version early this week with: - a full scancode scan run, collecting the matched texts, detected license ids and scores - reviewing anything where there was a license detected (about 500+ files) to ensure that the applied SPDX license was correct - reviewing anything where there was no detection but the patch license was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied SPDX license was correct This produced a worksheet with 20 files needing minor correction. This worksheet was then exported into 3 different .csv files for the different types of files to be modified. These .csv files were then reviewed by Greg. Thomas wrote a script to parse the csv files and add the proper SPDX tag to the file, in the format that the file expected. This script was further refined by Greg based on the output to detect more types of files automatically and to distinguish between header and source .c files (which need different comment types.) Finally Greg ran the script using the .csv files to generate the patches. Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-30ext4: Don't clear SGID when inheriting ACLsJan Kara
When new directory 'DIR1' is created in a directory 'DIR0' with SGID bit set, DIR1 is expected to have SGID bit set (and owning group equal to the owning group of 'DIR0'). However when 'DIR0' also has some default ACLs that 'DIR1' inherits, setting these ACLs will result in SGID bit on 'DIR1' to get cleared if user is not member of the owning group. Fix the problem by moving posix_acl_update_mode() out of __ext4_set_acl() into ext4_set_acl(). That way the function will not be called when inheriting ACLs which is what we want as it prevents SGID bit clearing and the mode has been properly set by posix_acl_create() anyway. Fixes: 073931017b49d9458aa351605b43a7e34598caef CC: stable@vger.kernel.org Signed-off-by: Theodore Ts'o <tytso@mit.edu> Signed-off-by: Jan Kara <jack@suse.cz> Reviewed-by: Andreas Gruenbacher <agruenba@redhat.com>
2017-07-30ext4: preserve i_mode if __ext4_set_acl() failsErnesto A. Fernández
When changing a file's acl mask, __ext4_set_acl() will first set the group bits of i_mode to the value of the mask, and only then set the actual extended attribute representing the new acl. If the second part fails (due to lack of space, for example) and the file had no acl attribute to begin with, the system will from now on assume that the mask permission bits are actual group permission bits, potentially granting access to the wrong users. Prevent this by only changing the inode mode after the acl has been set. Signed-off-by: Ernesto A. Fernández <ernesto.mnd.fernandez@gmail.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu> Reviewed-by: Jan Kara <jack@suse.cz>
2017-07-06ext4: fix __ext4_new_inode() journal credits calculationTahsin Erdogan
ea_inode feature allows creating extended attributes that are up to 64k in size. Update __ext4_new_inode() to pick increased credit limits. To avoid overallocating too many journal credits, update __ext4_xattr_set_credits() to make a distinction between xattr create vs update. This helps __ext4_new_inode() because all attributes are known to be new, so we can save credits that are normally needed to delete old values. Also, have fscrypt specify its maximum context size so that we don't end up allocating credits for 64k size. Signed-off-by: Tahsin Erdogan <tahsin@google.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2017-06-22ext4: xattr inode deduplicationTahsin Erdogan
Ext4 now supports xattr values that are up to 64k in size (vfs limit). Large xattr values are stored in external inodes each one holding a single value. Once written the data blocks of these inodes are immutable. The real world use cases are expected to have a lot of value duplication such as inherited acls etc. To reduce data duplication on disk, this patch implements a deduplicator that allows sharing of xattr inodes. The deduplication is based on an in-memory hash lookup that is a best effort sharing scheme. When a xattr inode is read from disk (i.e. getxattr() call), its crc32c hash is added to a hash table. Before creating a new xattr inode for a value being set, the hash table is checked to see if an existing inode holds an identical value. If such an inode is found, the ref count on that inode is incremented. On value removal the ref count is decremented and if it reaches zero the inode is deleted. The quota charging for such inodes is manually managed. Every reference holder is charged the full size as if there was no sharing happening. This is consistent with how xattr blocks are also charged. [ Fixed up journal credits calculation to handle inline data and the rare case where an shared xattr block can get freed when two thread race on breaking the xattr block sharing. --tytso ] Signed-off-by: Tahsin Erdogan <tahsin@google.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2017-06-21ext4: improve journal credit handling in set xattr pathsTahsin Erdogan
Both ext4_set_acl() and ext4_set_context() need to be made aware of ea_inode feature when it comes to credits calculation. Also add a sufficient credits check in ext4_xattr_set_handle() right after xattr write lock is grabbed. Original credits calculation is done outside the lock so there is a possiblity that the initially calculated credits are not sufficient anymore. Signed-off-by: Tahsin Erdogan <tahsin@google.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2017-05-24ext4: fix quota charging for shared xattr blocksTahsin Erdogan
ext4_xattr_block_set() calls dquot_alloc_block() to charge for an xattr block when new references are made. However if dquot_initialize() hasn't been called on an inode, request for charging is effectively ignored because ext4_inode_info->i_dquot is not initialized yet. Add dquot_initialize() to call paths that lead to ext4_xattr_block_set(). Signed-off-by: Tahsin Erdogan <tahsin@google.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu> Reviewed-by: Jan Kara <jack@suse.cz>
2016-11-14ext4: use current_time() for inode timestampsDeepa Dinamani
CURRENT_TIME_SEC and CURRENT_TIME are not y2038 safe. current_time() will be transitioned to be y2038 safe along with vfs. current_time() returns timestamps according to the granularities set in the super_block. The granularity check in ext4_current_time() to call current_time() or CURRENT_TIME_SEC is not required. Use current_time() directly to obtain timestamps unconditionally, and remove ext4_current_time(). Quota files are assumed to be on the same filesystem. Hence, use current_time() for these files as well. Signed-off-by: Deepa Dinamani <deepa.kernel@gmail.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu> Reviewed-by: Arnd Bergmann <arnd@arndb.de>
2016-09-22posix_acl: Clear SGID bit when setting file permissionsJan Kara
When file permissions are modified via chmod(2) and the user is not in the owning group or capable of CAP_FSETID, the setgid bit is cleared in inode_change_ok(). Setting a POSIX ACL via setxattr(2) sets the file permissions as well as the new ACL, but doesn't clear the setgid bit in a similar way; this allows to bypass the check in chmod(2). Fix that. References: CVE-2016-7097 Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Jeff Layton <jlayton@redhat.com> Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
2016-03-31posix_acl: Inode acl caching fixesAndreas Gruenbacher
When get_acl() is called for an inode whose ACL is not cached yet, the get_acl inode operation is called to fetch the ACL from the filesystem. The inode operation is responsible for updating the cached acl with set_cached_acl(). This is done without locking at the VFS level, so another task can call set_cached_acl() or forget_cached_acl() before the get_acl inode operation gets to calling set_cached_acl(), and then get_acl's call to set_cached_acl() results in caching an outdate ACL. Prevent this from happening by setting the cached ACL pointer to a task-specific sentinel value before calling the get_acl inode operation. Move the responsibility for updating the cached ACL from the get_acl inode operations to get_acl(). There, only set the cached ACL if the sentinel value hasn't changed. The sentinel values are chosen to have odd values. Likewise, the value of ACL_NOT_CACHED is odd. In contrast, ACL object pointers always have an even value (ACLs are aligned in memory). This allows to distinguish uncached ACLs values from ACL objects. In addition, switch from guarding inode->i_acl and inode->i_default_acl upates by the inode->i_lock spinlock to using xchg() and cmpxchg(). Filesystems that do not want ACLs returned from their get_acl inode operations to be cached must call forget_cached_acl() to prevent the VFS from doing so. (Patch written by Al Viro and Andreas Gruenbacher.) Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-04-02ext4: remove unused header filesSheng Yong
Remove unused header files and header files which are included in ext4.h. Signed-off-by: Sheng Yong <shengyong1@huawei.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2014-01-25ext2/3/4: use generic posix ACL infrastructureChristoph Hellwig
Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-01-25fs: make posix_acl_create more usefulChristoph Hellwig
Rename the current posix_acl_created to __posix_acl_create and add a fully featured helper to set up the ACLs on file creation that uses get_acl(). Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-01-25fs: make posix_acl_chmod more usefulChristoph Hellwig
Rename the current posix_acl_chmod to __posix_acl_chmod and add a fully featured ACL chmod helper that uses the ->set_acl inode operation. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-02-09ext4: fix the number of credits needed for acl ops with inline dataTheodore Ts'o
Operations which modify extended attributes may need extra journal credits if inline data is used, since there is a chance that some extended attributes may need to get pushed to an external attribute block. Changes to reflect this was made in xattr.c, but they were missed in fs/ext4/acl.c. To fix this, abstract the calculation of the number of credits needed for xattr operations to an inline function defined in ext4_jbd2.h, and use it in acl.c and xattr.c. Also move the function declarations used in inline.c from xattr.h (where they are non-obviously hidden, and caused problems since ext4_jbd2.h needs to use the function ext4_has_inline_data), and move them to ext4.h. Signed-off-by: "Theodore Ts'o" <tytso@mit.edu> Reviewed-by: Tao Ma <boyu.mt@taobao.com> Reviewed-by: Jan Kara <jack@suse.cz>
2013-02-08ext4: pass context information to jbd2__journal_start()Theodore Ts'o
So we can better understand what bits of ext4 are responsible for long-running jbd2 handles, use jbd2__journal_start() so we can pass context information for logging purposes. The recommended way for finding the longer-running handles is: T=/sys/kernel/debug/tracing EVENT=$T/events/jbd2/jbd2_handle_stats echo "interval > 5" > $EVENT/filter echo 1 > $EVENT/enable ./run-my-fs-benchmark cat $T/trace > /tmp/problem-handles This will list handles that were active for longer than 20ms. Having longer-running handles is bad, because a commit started at the wrong time could stall for those 20+ milliseconds, which could delay an fsync() or an O_SYNC operation. Here is an example line from the trace file describing a handle which lived on for 311 jiffies, or over 1.2 seconds: postmark-2917 [000] .... 196.435786: jbd2_handle_stats: dev 254,32 tid 570 type 2 line_no 2541 interval 311 sync 0 requested_blocks 1 dirtied_blocks 0 Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2012-11-08ext4: fix memory leak in ext4_xattr_set_acl()'s error pathEugene Shatokhin
In ext4_xattr_set_acl(), if ext4_journal_start() returns an error, posix_acl_release() will not be called for 'acl' which may result in a memory leak. This patch fixes that. Reviewed-by: Lukas Czerner <lczerner@redhat.com> Signed-off-by: Eugene Shatokhin <eugene.shatokhin@rosalab.ru> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu> Cc: stable@vger.kernel.org
2012-09-18userns: Convert extN to support kuids and kgids in posix aclsEric W. Biederman
Convert ext2, ext3, and ext4 to fully support the posix acl changes, using e_uid e_gid instead e_id. Enabled building with posix acls enabled, all filesystems supporting user namespaces, now also support posix acls when user namespaces are enabled. Cc: Theodore Tso <tytso@mit.edu> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andreas Dilger <adilger.kernel@dilger.ca> Cc: Jan Kara <jack@suse.cz> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
2012-09-18userns: Pass a userns parameter into posix_acl_to_xattr and posix_acl_from_xattrEric W. Biederman
- Pass the user namespace the uid and gid values in the xattr are stored in into posix_acl_from_xattr. - Pass the user namespace kuid and kgid values should be converted into when storing uid and gid values in an xattr in posix_acl_to_xattr. - Modify all callers of posix_acl_from_xattr and posix_acl_to_xattr to pass in &init_user_ns. In the short term this change is not strictly needed but it makes the code clearer. In the longer term this change is necessary to be able to mount filesystems outside of the initial user namespace that natively store posix acls in the linux xattr format. Cc: Theodore Tso <tytso@mit.edu> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andreas Dilger <adilger.kernel@dilger.ca> Cc: Jan Kara <jack@suse.cz> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2011-08-01switch posix_acl_equiv_mode() to umode_t *Al Viro
... so that &inode->i_mode could be passed to it Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-08-01switch posix_acl_create() to umode_t *Al Viro
so we can pass &inode->i_mode to it Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-07-25fs: take the ACL checks to common codeChristoph Hellwig
Replace the ->check_acl method with a ->get_acl method that simply reads an ACL from disk after having a cache miss. This means we can replace the ACL checking boilerplate code with a single implementation in namei.c. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-07-25kill boilerplates around posix_acl_create_masq()Al Viro
new helper: posix_acl_create(&acl, gfp, mode_p). Replaces acl with modified clone, on failure releases acl and replaces with NULL. Returns 0 or -ve on error. All callers of posix_acl_create_masq() switched. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-07-25kill boilerplate around posix_acl_chmod_masq()Al Viro
new helper: posix_acl_chmod(&acl, gfp, mode). Replaces acl with modified clone or with NULL if that has failed; returns 0 or -ve on error. All callers of posix_acl_chmod_masq() switched to that - they'd been doing exactly the same thing. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-07-25vfs: move ACL cache lookup into generic codeLinus Torvalds
This moves logic for checking the cached ACL values from low-level filesystems into generic code. The end result is a streamlined ACL check that doesn't need to load the inode->i_op->check_acl pointer at all for the common cached case. The filesystems also don't need to check for a non-blocking RCU walk case in their acl_check() functions, because that is all handled at a VFS layer. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-07-20->permission() sanitizing: don't pass flags to ->check_acl()Al Viro
not used in the instances anymore. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-07-20->permission() sanitizing: pass MAY_NOT_BLOCK to ->check_acl()Al Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-03-23userns: rename is_owner_or_cap to inode_owner_or_capableSerge E. Hallyn
And give it a kernel-doc comment. [akpm@linux-foundation.org: btrfs changed in linux-next] Signed-off-by: Serge E. Hallyn <serge.hallyn@canonical.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Daniel Lezcano <daniel.lezcano@free.fr> Acked-by: David Howells <dhowells@redhat.com> Cc: James Morris <jmorris@namei.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-01-07ext2,3,4: provide simple rcu-walk ACL implementationNick Piggin
This simple implementation just checks for no ACLs on the inode, and if so, then the rcu-walk may proceed, otherwise fail it. Signed-off-by: Nick Piggin <npiggin@kernel.dk>
2011-01-07fs: provide rcu-walk aware permission i_opsNick Piggin
Signed-off-by: Nick Piggin <npiggin@kernel.dk>
2010-06-15ext4: update ctime when changing the file's permission by setfaclJan Kara
ext4 didn't update the ctime of the file when its permission was changed. Steps to reproduce: # touch aaa # stat -c %Z aaa 1275289822 # setfacl -m 'u::x,g::x,o::x' aaa # stat -c %Z aaa 1275289822 <- unchanged But, according to the spec of the ctime, ext4 must update it. Port of ext3 patch by Miao Xie <miaox@cn.fujitsu.com>. CC: linux-ext4@vger.kernel.org Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2010-05-21ext4: constify xattr_handlerStephen Hemminger
Signed-off-by: Stephen Hemminger <shemminger@vyatta.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-12-16sanitize xattr handler prototypesChristoph Hellwig
Add a flags argument to struct xattr_handler and pass it to all xattr handler methods. This allows using the same methods for multiple handlers, e.g. for the ACL methods which perform exactly the same action for the access and default ACLs, just using a different underlying attribute. With a little more groundwork it'll also allow sharing the methods for the regular user/trusted/secure handlers in extN, ocfs2 and jffs2 like it's already done for xfs in this patch. Also change the inode argument to the handlers to a dentry to allow using the handlers mechnism for filesystems that require it later, e.g. cifs. [with GFS2 bits updated by Steven Whitehouse <swhiteho@redhat.com>] Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: James Morris <jmorris@namei.org> Acked-by: Joel Becker <joel.becker@oracle.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-09-08ext[234]: move over to 'check_acl' permission modelLinus Torvalds
Don't implement per-filesystem 'extX_permission()' functions that have to be called for every path component operation, and instead just expose the actual ACL checking so that the VFS layer can now do it for us. Reviewed-by: James Morris <jmorris@namei.org> Acked-by: Serge Hallyn <serue@us.ibm.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-24helpers for acl caching + switch to thoseAl Viro
helpers: get_cached_acl(inode, type), set_cached_acl(inode, type, acl), forget_cached_acl(inode, type). ubifs/xattr.c needed includes reordered, the rest is a plain switchover. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-06-24switch ext4 to inode->i_aclAl Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-06-17ext4: avoid unnecessary spinlock in critical POSIX ACL pathTheodore Ts'o
If a filesystem supports POSIX ACL's, the VFS layer expects the filesystem to do POSIX ACL checks on any files not owned by the caller, and it does this for every single pathname component that it looks up. That obviously can be pretty expensive if the filesystem isn't careful about it, especially with locking. That's doubly sad, since the common case tends to be that there are no ACL's associated with the files in question. ext4 already caches the ACL data so that it doesn't have to look it up over and over again, but it does so by taking the inode->i_lock spinlock on every lookup. Which is a noticeable overhead even if it's a private lock, especially on CPU's where the serialization is expensive (eg Intel Netburst aka 'P4'). For the special case of not actually having any ACL's, all that locking is unnecessary. Even if somebody else were to be changing the ACL's on another CPU, we simply don't care - if we've seen a NULL ACL, we might as well use it. So just load the ACL speculatively without any locking, and if it was NULL, just use it. If it's non-NULL (either because we had a cached entry, or because the cache hasn't been filled in at all), it means that we'll need to get the lock and re-load it properly. (This commit was ported from a patch originally authored by Linus for ext3.) Signed-off-by: "Theodore Ts'o" <tytso@mit.edu> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-03-31New helper - current_umask()Al Viro
current->fs->umask is what most of fs_struct users are doing. Put that into a helper function. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2008-07-26ext4: Cleanup whitespace and other miscellaneous style issuesTheodore Ts'o
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2008-07-26[PATCH] sanitize ->permission() prototypeAl Viro
* kill nameidata * argument; map the 3 bits in ->flags anybody cares about to new MAY_... ones and pass with the mask. * kill redundant gfs2_iop_permission() * sanitize ecryptfs_permission() * fix remaining places where ->permission() instances might barf on new MAY_... found in mask. The obvious next target in that direction is permission(9) folded fix for nfs_permission() breakage from Miklos Szeredi <mszeredi@suse.cz> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2008-04-29ext4: move headers out of include/linuxChristoph Hellwig
Move ext4 headers out of include/linux. This is just the trivial move, there's some more thing that could be done later. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Mingming Cao <cmm@us.ibm.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2008-04-29ext4: fix wrong gfp type under transactionJosef Bacik
This fixes the allocations with GFP_KERNEL while under a transaction problems in ext4. This patch is the same as its ext3 counterpart, just switches these to GFP_NOFS. Signed-off-by: Josef Bacik <jbacik@redhat.com> Cc: <linux-ext4@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Mingming Cao <cmm@us.ibm.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2007-07-17Introduce is_owner_or_cap() to wrap CAP_FOWNER use with fsuid checkSatyam Sharma
Introduce is_owner_or_cap() macro in fs.h, and convert over relevant users to it. This is done because we want to avoid bugs in the future where we check for only effective fsuid of the current task against a file's owning uid, without simultaneously checking for CAP_FOWNER as well, thus violating its semantics. [ XFS uses special macros and structures, and in general looked ... untouchable, so we leave it alone -- but it has been looked over. ] The (current->fsuid != inode->i_uid) check in generic_permission() and exec_permission_lite() is left alone, because those operations are covered by CAP_DAC_OVERRIDE and CAP_DAC_READ_SEARCH. Similarly operations falling under the purview of CAP_CHOWN and CAP_LEASE are also left alone. Signed-off-by: Satyam Sharma <ssatyam@cse.iitk.ac.in> Cc: Al Viro <viro@ftp.linux.org.uk> Acked-by: Serge E. Hallyn <serge@hallyn.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2006-10-11[PATCH] ext4 whitespace cleanupsAndrew Morton
Someone's tab key is emitting spaces. Attempt to repair some of the damage. Cc: <linux-ext4@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-11[PATCH] jbd2: enable building of jbd2 and have ext4 use it rather than jbdMingming Cao
Reworked from a patch by Mingming Cao and Randy Dunlap Signed-off-By: Randy Dunlap <rdunlap@xenotime.net> Signed-off-by: Mingming Cao <cmm@us.ibm.com> Signed-off-by: Dave Kleikamp <shaggy@austin.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-11[PATCH] ext4: rename ext4 symbols to avoid duplication of ext3 symbolsMingming Cao
Mingming Cao originally did this work, and Shaggy reproduced it using some scripts from her. Signed-off-by: Mingming Cao <cmm@us.ibm.com> Signed-off-by: Dave Kleikamp <shaggy@austin.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-11[PATCH] ext4: initial copy of files from ext3Dave Kleikamp
Start of the ext4 patch series. See Documentation/filesystems/ext4.txt for details. This is a simple copy of the files in fs/ext3 to fs/ext4 and /usr/incude/linux/ext3* to /usr/include/ex4* Signed-off-by: Dave Kleikamp <shaggy@austin.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>