From cbdd289c5486f28dc0cf534c2a7f93df0b6660a1 Mon Sep 17 00:00:00 2001 From: Michael Jeanson Date: Thu, 21 Apr 2016 16:11:04 -0400 Subject: [PATCH] Fix: writeback probe on RHEL >= 3.10.0-327.10.1 Signed-off-by: Michael Jeanson Signed-off-by: Mathieu Desnoyers --- .../events/lttng-module/writeback.h | 37 ++++++++++++++----- 1 file changed, 27 insertions(+), 10 deletions(-) diff --git a/instrumentation/events/lttng-module/writeback.h b/instrumentation/events/lttng-module/writeback.h index a215f55b..6006c294 100644 --- a/instrumentation/events/lttng-module/writeback.h +++ b/instrumentation/events/lttng-module/writeback.h @@ -13,17 +13,34 @@ #ifndef _TRACE_WRITEBACK_DEF_ #define _TRACE_WRITEBACK_DEF_ -#if (LINUX_VERSION_CODE < KERNEL_VERSION(4,0,0) && \ - LTTNG_RHEL_VERSION_CODE < LTTNG_RHEL_KERNEL_VERSION(3,10,0,327,10,1)) -static inline struct backing_dev_info *inode_to_bdi(struct inode *inode) +/* + * Vanilla kernels before 4.0 do not implement inode_to_bdi + * RHEL kernels before 3.10.0-327.10.1 do not implement inode_to_bdi + * RHEL kernel 3.10.0-327.10.1 has inode_to_bdi + * RHEL kernel 3.10.0-327.13.1 includes a partial merge of upstream + * commit a212b105b07d75b48b1a166378282e8a77fbf53d which inlines + * inode_to_bdi but not sb_is_blkdev_sb making it unusable by modules. + */ +#if (LINUX_VERSION_CODE < KERNEL_VERSION(4,0,0)) +static inline struct backing_dev_info *lttng_inode_to_bdi(struct inode *inode) { - struct super_block *sb = inode->i_sb; + struct super_block *sb; + + if (!inode) + return &noop_backing_dev_info; + + sb = inode->i_sb; if (strcmp(sb->s_type->name, "bdev") == 0) return inode->i_mapping->backing_dev_info; return sb->s_bdi; } +#else +static inline struct backing_dev_info *lttng_inode_to_bdi(struct inode *inode) +{ + return inode_to_bdi(inode); +} #endif /* #if (LINUX_VERSION_CODE < KERNEL_VERSION(4,0,0)) */ #endif @@ -65,7 +82,7 @@ LTTNG_TRACEPOINT_EVENT(writeback_dirty_page, TP_ARGS(page, mapping), TP_FIELDS( ctf_array_text(char, name, - mapping ? dev_name(inode_to_bdi(mapping->host)->dev) : "(unknown)", 32) + mapping ? dev_name(lttng_inode_to_bdi(mapping->host)->dev) : "(unknown)", 32) ctf_integer(unsigned long, ino, mapping ? mapping->host->i_ino : 0) ctf_integer(pgoff_t, index, page->index) ) @@ -77,8 +94,8 @@ LTTNG_TRACEPOINT_EVENT_CLASS(writeback_dirty_inode_template, TP_FIELDS( /* may be called for files on pseudo FSes w/ unregistered bdi */ ctf_array_text(char, name, - inode_to_bdi(inode)->dev ? - dev_name(inode_to_bdi(inode)->dev) : "(unknown)", 32) + lttng_inode_to_bdi(inode)->dev ? + dev_name(lttng_inode_to_bdi(inode)->dev) : "(unknown)", 32) ctf_integer(unsigned long, ino, inode->i_ino) ctf_integer(unsigned long, state, inode->i_state) ctf_integer(unsigned long, flags, flags) @@ -97,7 +114,7 @@ LTTNG_TRACEPOINT_EVENT_CLASS(writeback_write_inode_template, TP_ARGS(inode, wbc), TP_FIELDS( ctf_array_text(char, name, - dev_name(inode_to_bdi(inode)->dev), 32) + dev_name(lttng_inode_to_bdi(inode)->dev), 32) ctf_integer(unsigned long, ino, inode->i_ino) ctf_integer(int, sync_mode, wbc->sync_mode) ) @@ -609,7 +626,7 @@ LTTNG_TRACEPOINT_EVENT(writeback_sb_inodes_requeue, TP_FIELDS( ctf_array_text(char, name, - dev_name(inode_to_bdi(inode)->dev), 32) + dev_name(lttng_inode_to_bdi(inode)->dev), 32) ctf_integer(unsigned long, ino, inode->i_ino) ctf_integer(unsigned long, state, inode->i_state) ctf_integer(unsigned long, dirtied_when, inode->dirtied_when) @@ -657,7 +674,7 @@ LTTNG_TRACEPOINT_EVENT_CLASS(writeback_single_inode_template, TP_FIELDS( ctf_array_text(char, name, - dev_name(inode_to_bdi(inode)->dev), 32) + dev_name(lttng_inode_to_bdi(inode)->dev), 32) ctf_integer(unsigned long, ino, inode->i_ino) ctf_integer(unsigned long, state, inode->i_state) ctf_integer(unsigned long, dirtied_when, inode->dirtied_when) -- 2.34.1